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53-1 002 43 7-0 1 Januar y 20 12 ® Ser v erIron ADX Global Ser v er Load Balancing Guide Suppor ting Brocade Ser verIr on ADX version 12.4.00.
© 20 12 Brocade Comm unications Systems, Inc. All Rights Reserved. Broc ade, the B-wing symbol, B igIron, DCFM, D CX, Fabric OS , FastIr on, IronVie w, NetIron, SAN Heal th, Ser verIr on, T urboIr on.
ServerIron ADX Global Server Load Balancing Guide iii 53-1002437-01 Contents About This Document Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix Suppor ted har dware and software . . . . . . .
iv ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Site persist ence in GSLB using stickiness . . . . . . . . . . . . . . . . . . . . . 64 Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Enabling sticky GSLB .
ServerIron ADX Global Server Load Balancing Guide v 53-1002437-01 DNSSEC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112 V erification with DIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
vi ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 Displaying sit e information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 Displaying real server inf ormation .
ServerIron ADX Global Server Load Balancing Guide vii 53-1002437-01 Displaying GSLB for IPv6 configurations . . . . . . . . . . . . . . . . . . . . . 23 1 Show commands f or basic GSLB configurations . . . . . . . . . . . 23 1 Show commands f or advanced f eatures .
viii ServerIron ADX Global Server Load Balancing Guide 53-1002437-01.
ServerIron ADX Global Server Load Balancing Guide ix 53-1002437-01 About This Document Audience This document is designed f or system administ rators with a working kno wledge of Lay er 2 and Lay er 3 switching an d routing.
x ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 For readability , comma nd names in the narrative por tions of this guide are presented in bold: for exa mp le , show version . Notes, cautions, and danger notices The f ollowing notices and statements are used in this manual.
ServerIron ADX Global Server Load Balancing Guide xi 53-1002437-01 Related publications The f ollowing Brocade documents supplement the inf ormation in this guide: • Release Not es for ServerIron Switch and Rout er Sof tware T raf f icWorks 12.
xii ServerIron ADX Global Server Load Balancing Guide 53-1002437-01.
ServerIron ADX Global Server Load Balancing Guide 1 53-1002437-01 Chapter 1 Global Server Load Balancing Global Server Load Balancing overview Global Server Load Balancing (GSLB) enables a Se r verIr .
2 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Global Server Load Balancing overview 1 If the local DNS server does no t have an addre ss record f or the request ed ser ver , the local DNS ser ver makes a recursive query. When a request reaches an authoritativ e DNS ser ver , that DNS server responds to this DNS quer y .
ServerIron ADX Global Server Load Balancing Guide 3 53-1002437-01 Global Server Load Balancing overview 1 • Session table statistics and CPU load information — The sit e Ser verIron ADXs rep or t this information t o the GSLB Ser verIron ADX at regula r int er vals.
4 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Global Server Load Balancing overview 1 • IMAP4: the we ll -k n own na m e fo r p or t 143 • LD AP : the well-known name for port .
ServerIron ADX Global Server Load Balancing Guide 5 53-1002437-01 Global Server Load Balancing overview 1 This example sho ws a Ser verIr on ADX configured as a DNS pro xy . The Ser verIron ADX is configured as a DNS pro xy for the DNS server that is author itativ e for the domain brocade.
6 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Global Server Load Balancing overview 1 servers that receive the recor ds retain them in th eir databases f or only 1 0 seconds. Af ter the ten seconds expire, subsequent requests fr om the clien t initiate ano ther query to the authoritative DNS server .
ServerIron ADX Global Server Load Balancing Guide 7 53-1002437-01 Global Server Load Balancing overview 1 If the GSLB policy reje cts all of the sites, the GSLB Ser verIr on ADX sends the DNS reply unchanged to th e cl ie nt . All of these metrics ha ve def ault values but you ca n change the values if needed.
8 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Global Server Load Balancing overview 1 NOTE Y ou cannot use the weight ed IP metric if the w eighted site me tric is enabled. The GSLB ServerIr on ADX uses relative per centages in order to achie ve 1 0 0% to tal weight distribution.
ServerIron ADX Global Server Load Balancing Guide 9 53-1002437-01 Global Server Load Balancing overview 1 Round-trip time between the remo te ServerIron ADX and the client The Round-trip time (RTT) is.
10 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Global Server Load Balancing overview 1 Site ServerIron AD X’s connection load A GSLB site’s connection load is the av erage numb er of new connections per second on the sit e, ov er a given number of int er vals.
ServerIron ADX Global Server Load Balancing Guide 11 53-1002437-01 Global Server Load Balancing overview 1 Site ServerIron ADX’s administrative preference The administrative pref erence is an optional metric .
12 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Global Server Load Balancing overview 1 Use the round robin selection metric instead of th e least response selectio n m etric when yo u want to pre vent the GSLB ServerIr on ADX from fa voring ne w or recently recov ered sites over pre viously configured active sites.
ServerIron ADX Global Server Load Balancing Guide 13 53-1002437-01 Minimum required conf iguration 1 NOTE The sum of number of VIPs configured and the number of GSLB hosts configured on the GSLB ServerIron ADX should not exce ed 102 4. Similarl y , the sum of real ser vers configured and the number of DNS IP addresses should not exceed 40 96.
14 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Minimum required configuratio n 1 Issue show gslb site on the controller to display site communication information. The stat e displays “CONNECTION EST ABLISHED” when communication is successful.
ServerIron ADX Global Server Load Balancing Guide 15 53-1002437-01 Configuring GSLB 1 Configuring GSLB The examples in the pr ocedures in this sectio n are based on the configuration shown in Figu re 1 on page 4 . TA B L E 1 Configuration t asks: Global SLB Feature See page.
16 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Configuring GSLB 1 Y ou can configure the GSLB ServerIr on ADX to be a pr oxy f or more than one DNS server . As shown in the example in Figure 1 on page 4 , y ou implement GSLB by connecting a Ser verIr on ADX to an authoritativ e DNS ser ver .
ServerIron ADX Global Server Load Balancing Guide 17 53-1002437-01 Proxy for DNS server 1 Proxy for DNS server NOTE The f ollowing scenario is fo r switch sof tware. If yo u are using r outer software, then all y ou need is an interface IP on the ServerIr on ADX that can reach the DNS ser ver .
18 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Proxy for DNS server 1 For e xample, the GSLB ServerIr on ADX shown in Figure 1 on page 4 needs a source IP address in the subnet 209. 15 7 .23.x. Without this source IP a ddress, La yer 4 and La yer 7 health checks t o the ServerIron ADXs at the S unnyvale sit e (209.
ServerIron ADX Global Server Load Balancing Guide 19 53-1002437-01 Proxy for DNS server 1 Syntax: [no] ser ver real-name <t ext> <ip- addr> Syntax: [no] por t dns pro xy Syntax: [no] por t.
20 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Proxy for DNS server 1 ServerIronADX(config-gslb-site-sunnyvale)# si-name slb-2 209.157.22.210 200 NOTE The administrative pref erence metric is disabled b y default, which means it is no t used by the GSLB policy .
ServerIron ADX Global Server Load Balancing Guide 21 53-1002437-01 Proxy for DNS server 1 Specifying GSLB controller locations By default, the GSLB contr oller is assigned to the Nor th America geographic. Specify the GSLB controller location by entering the f ollowin g command at the global configuration leve l.
22 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Proxy for DNS server 1 • IMAP4 : the well-kno wn nam e f or por t 1 43 • LDAP: the well-known name for por t 389 • NNTP: the we.
ServerIron ADX Global Server Load Balancing Guide 23 53-1002437-01 Proxy for DNS server 1 T o display the status of CNAM E, enter the f ollowing command.
24 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Proxy for DNS server 1 Syntax: host-info <h ost-name> http | <TCP-portnum> status-code <range> [<range> [ <range> [ <range> ]]] Y ou can specify up to four ra nges (total of eigh t values).
ServerIron ADX Global Server Load Balancing Guide 25 53-1002437-01 Proxy for DNS server 1 Syntax: host-info <h ost-name> alias <alias-name> NOTE Make sure y ou configu re the alias only af ter config uring the zone and the host application the alias is for , as shown in the e xample abo ve.
26 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Private VIPs for GSLB 1 ServerIronADX(config)# gslb dns zone brocade.com ServerIronADX(config-gslb-dns-brocade.com)# host-info www http ServerIronADX(config-gslb-dns-brocade.com)# host-info www ip-list 209.
ServerIron ADX Global Server Load Balancing Guide 27 53-1002437-01 Private VIPs for GSLB 1 FIGURE 3 GSLB and privat e VIPs Using the ex ample in Figure 3 , suppose the configu ration specifies that the public IP address will be us e d by b ot h t he p ee r GS L B S e r ve rI ro n A D X A a nd t he si te Se r ver Iro n A D X B .
28 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Private VIPs for GSLB 1 Private VIP display information T o obtain more information about the publ ic an d private IP addresse s conf.
ServerIron ADX Global Server Load Balancing Guide 29 53-1002437-01 Configuring GSLB protoc ol parameters 1 The displa y shows that the public IP address, 20 7 .
30 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Configuring GSLB protocol parame ters 1 The <tcp-por tnum> paramet er specifies the TCP port number you want the Ser verIr on ADX to use fo r exc h a n g i n g G S L B i n fo r m a t i o n with other ServerIr on ADXs.
ServerIron ADX Global Server Load Balancing Guide 31 53-1002437-01 Configuring GSLB protoc ol parameters 1 Removing IP addresses for sites th at fail a health check By default, the S er verIron ADX does no t remov e an IP address from a DNS re ply even if the address fails a health check.
32 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Configuring GSLB protocol parame ters 1 T o display the stat e of this feature, enter the sh ow gslb policy command. The DNS best-only field indicates whether the feature is enabled or disabled.
ServerIron ADX Global Server Load Balancing Guide 33 53-1002437-01 Configuring GSLB protoc ol parameters 1 ServerIronADX(config-gslb-policy)# no dns ttl Syntax: [no] dns ttl Enabling DNS override By default, the GSLB ServerIr on ADX selects the best site IP address from among the addresses contained in the DNS reply .
34 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Configuring GSLB protocol parame ters 1 When you enable DNS override, th e GSLB Ser verIr on ADX replaces the IP addresses in the DNS reply with the “b est” of the pro xy ser ver a ddresses y ou specify .
ServerIron ADX Global Server Load Balancing Guide 35 53-1002437-01 Configuring GSLB protoc ol parameters 1 TA B L E 2 GSLB policy metrics Metric Default Configuration options Ser ver (host) health Enabled.
36 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Configuring GSLB protocol parame ters 1 Connection load Disabled. Y ou can enable this metric. Y o u also can change the data collection int er val, the number of intervals used t o calculate the connection load a verage, and the relativ e weights of the int er vals.
ServerIron ADX Global Server Load Balancing Guide 37 53-1002437-01 Configuring GSLB protoc ol parameters 1 Af ter changing policy values, you can displa y the new v alues using the show gslb policy command.
38 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Configuring GSLB protocol parame ters 1 • active bindings: The ServerIr on ADX’s preference f or the IP address with the highest number of active bindings. • capacity : The remote Ser verIron ADX’s session capacity threshold.
ServerIron ADX Global Server Load Balancing Guide 39 53-1002437-01 Configuring GSLB protoc ol parameters 1 ServerIronADX(config)# gslb policy ServerIronADX(config-gslb-policy)# health-check Se.
40 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Configuring GSLB protocol parame ters 1 Implementing the we ighted IP metric Beginning with rout er sof tware release 08. 1. 00R, you can configure the ServerIron ADX t o distribute GSLB traffic among IP addresses in a DNS reply , based on weights assigned to the I P addresses.
ServerIron ADX Global Server Load Balancing Guide 41 53-1002437-01 Configuring GSLB protoc ol parameters 1 • The number of eligible I P addresses to be ev aluated b y the weighte d IP metric and the.
42 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Configuring GSLB protocol paramete rs 1 <IP address> is the IP address f or which you are assigning a weight.
ServerIron ADX Global Server Load Balancing Guide 43 53-1002437-01 Configuring GSLB protoc ol parameters 1 Now consider the e xample in Ta b l e 6 . In this example, the to tal of the Configured weight ed site metrics (second column) does not equal 1 00.
44 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Configuring GSLB protocol parame ters 1 Traffic distribution sp ecifications In general, DNS response selection count ers are maintained per IP address, per domain name. Fo r exam ple, suppose you configure three GSLB sites wi th assign ed weights.
ServerIron ADX Global Server Load Balancing Guide 45 53-1002437-01 Configuring GSLB protoc ol parameters 1 Displaying results of traffic distribution for Weighted Sites T o view the results of traffic distribution af ter co n figuring weighted sit e m etrics, enter the f ollowing command.
46 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Configuring GSLB protocol paramete rs 1 The second example sho ws the third site. SITE: THREE * a.b.c DNS Requests: 36 ServerIronADX VIP Selection (%) == === ============= 1.
ServerIron ADX Global Server Load Balancing Guide 47 53-1002437-01 Configuring GSLB protoc ol parameters 1 For each VIP of interest, the GSLB Ser verIron ADX stores the number of acti ve bindings for the respective application port.
48 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Configuring GSLB protocol parame ters 1 GSLB active bindings enhancements The follo wing features ha ve been added to GSLB active bin.
ServerIron ADX Global Server Load Balancing Guide 49 53-1002437-01 Configuring GSLB protoc ol parameters 1 ServerIronADX# configure terminal ServerIronADX(config)# gslb dns zone company.com ServerIronADX(config-gslb-dns-company.com)# host-info www http ServerIronADX(config-gslb-dns-company.
50 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Configuring GSLB protocol parame ters 1 ServerIronADX(config)# gslb policy ServerIronADX(config-gslb-policy)# connection-load limit 500 This command sets t he site connection limit to 500 connections.
ServerIron ADX Global Server Load Balancing Guide 51 53-1002437-01 Configuring GSLB protoc ol parameters 1 Changing the sample interv al weight The interval weights are the relative weights of each data sample within a set of sampling intervals.
52 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Configuring GSLB protocol parame ters 1 Yo u c a n c h a n g e t h e s e p a r a m e t e r s on an individual basis.
ServerIron ADX Global Server Load Balancing Guide 53 53-1002437-01 Configuring GSLB protoc ol parameters 1 Modifying round-trip time values The Round-trip time (RTT) is the amou nt of time that pass e.
54 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Configuring GSLB protocol parame ters 1 Syntax: [no] round- trip-time cache-interval <num> The <num> parameter specifies the aging interval and can be from 1 0-1,000,000 se conds (about 11-1 /2 days).
ServerIron ADX Global Server Load Balancing Guide 55 53-1002437-01 Configuring GSLB protoc ol parameters 1 ServerIronADX(config)# gslb policy ServerIronADX(config-gslb-policy)# round-trip-time explore-percentage 10 The command in this example changes the R TT explore percentage fr om 5% to 1 0 %.
56 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Secure GSLB 1 The <ip-addr> specifies the address of the c ache entr y. This is not necessarily the address of a remote sit e. The address you specify here is combin ed with the prefix length t o result in a network prefix (network por tion of an IP ad dres s).
ServerIron ADX Global Server Load Balancing Guide 57 53-1002437-01 Secure GSLB 1 • Peer authentication — Each netwo rk device must be authenticated bef ore it can connect to the GSLB netw ork. This check ensures that any peer a G SLB device communicat es with is the legitimate peer .
58 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Secure GSLB 1 RSA challenge dialogue Once the initial peer au thentication is complete , there is a challenge response dialogue betw een the two ServerIr on ADXs as follow s.
ServerIron ADX Global Server Load Balancing Guide 59 53-1002437-01 Secure GSLB 1 Configuring secure-communi cation on the controller On the GSLB contr oller , to enable the secure pr otocol instead of.
60 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Secure GSLB 1 ServerIron(config)#wr mem .Write startup-config in progress. ..Write startup-config done. ServerIron(config)#Saving SSH host keys process is ongoing. Please wait .
ServerIron ADX Global Server Load Balancing Guide 61 53-1002437-01 Secure GSLB 1 NOTE When you specify a TCP port for the k ey e xchange communication, DO NO T use por t 182, or the por t that you configured for GSLB communicati on traf fic. The default destination T CP por t f or key e xchange is 56895.
62 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Secure GSLB 1 9. Af ter the k ey-exchange (fingerprint) tak es place, the ke y must be save d on both the controller and site ServerIr on ADX using the cr ypto k ey-ex change sav e-peer-k ey command.
ServerIron ADX Global Server Load Balancing Guide 63 53-1002437-01 Secure GSLB 1 The one-ti me option configures the peer public ke ys for a one-ti me usage, which is the highest level of security . They e xpire af ter each T CP session to the peer device is disconnect ed.
64 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Site persistence in GSLB using stickiness 1 The <si-name> paramet er specifies the name of the peer sit e ServerIron ADX t o regenerate the session keys f or . The <s i-ip-addr ess> parameter specifies the I P address of the peer site ServerIr on ADX.
ServerIron ADX Global Server Load Balancing Guide 65 53-1002437-01 Site persistence in GSLB using stickiness 1 • Client IP address/prefix • Domain name the client requ ested • Selecte d IP addre.
66 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Site persisten ce in GSLB using stickiness 1 Enabling sticky GSLB Enabling sticky GSLB is the minimum required configuration.
ServerIron ADX Global Server Load Balancing Guide 67 53-1002437-01 Site persistence in GSLB using stickiness 1 Syntax: [no] sticky NOTE No special CLI command s need to be issued on the sit e ServerIron ADX. Allowing sticky sessions for a specific prefix length Y ou can all ow sticky sessions for a specific prefix length (not all hosts).
68 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Site persistence in GSLB using stickiness 1 Displaying current sticky GSLB sessions T o display current Sticky GSLB sessions, rcon s o le into a barrel processor (BP) and enter the following command.
ServerIron ADX Global Server Load Balancing Guide 69 53-1002437-01 Site persistence in GSLB using stickiness 1 Sticky GSLB counters T o display ho w many times an IP address was sele ct ed as the best cand idate f or a client request, enter the f ollowing command.
70 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Site persistence in GSLB using hashing 1 Deleting sticky GSLB sess ion for a specific client T o delete Sticky GSLB sessions for a specific client, enter a command such as the f ollowing: ServerIronADX#clear gslb sticky-session client-ip 100.
ServerIron ADX Global Server Load Balancing Guide 71 53-1002437-01 Site persistence in GSLB using hashing 1 T o display the hash table for all domains or a specific zone-name, ente r a command on the .
72 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Site persistence in GSLB using hashing 1 Example 1. 1. 1.42 yields hash inde x 45 {(1+1+1+42 %256) = 45 } 1 72.
ServerIron ADX Global Server Load Balancing Guide 73 53-1002437-01 Site persistence in GSLB using hashing 1 The hash table allocation look s like the f ollowing: Now the ne w IP address 1. 1. 1.43 is configured f or domain www .foo. com . The ServerIron ADX sorts the IP addresses for domain www .
74 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Site persistence in GSLB using hashing 1 SLB-ServerIronADX(config)#gslb policy SLB-ServerIronADX(config-gslb-policy)#hash-persist.
ServerIron ADX Global Server Load Balancing Guide 75 53-1002437-01 Site persistence in GSLB using hashing 1 SLB-ServerIronADX#clear gslb phash table zone-name gslb.
76 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Weighted distribution of sites with hash-based persistence 1 In the pre vious screen shot, the field "persist en t hash se lection count =7" means IP 1 00. 1. 1. 163 had been select ed 7 times in result of a match in the hash persistent policy .
ServerIron ADX Global Server Load Balancing Guide 77 53-1002437-01 Weighted distribution of sites with hash-based persist ence 1 • “Disabling rehash on change in hash weig ht configuration” on page 79 GSLB hash-b ased persiste nce GSLB pr ovides two methods f or persistence- Stic ky method and Hash-based persistence.
78 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Weighted distribution of sites with hash-based persistence 1 In our example, Hash bucket 0 will be assigned to 1.1.1.42 Hash bucket 1 will be assigned to 1.1.1.43 Hash bucket 2 will be assigned to 1.
ServerIron ADX Global Server Load Balancing Guide 79 53-1002437-01 Weighted distribution of sites with hash-based persist ence 1 The ServerIron ADX sorts the IP addresses for domain www .foo.com in ascending or der of the addresses as follo ws. 1.1.1.
80 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Weighted distribution of sites with hash-based persistence 1 NOTE All the existing CLI for old hash-based persist ence is applicable to w eighted hash based persistence also. It is not described in this document for the sake of brevity .
ServerIron ADX Global Server Load Balancing Guide 81 53-1002437-01 Weighted distribution of sites with hash-based persist ence 1 Configuring weights for domain IP addresses Weight ed Hash-based GSLB persist ence enables the user to d istribute the hash buck ets for th e domain in propor tion to the weights configured f o r the domain IP addresse s.
82 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Weighted distribution of sites with hash-based persistence 1 ServerIronADX(config-gslb-policy)# hash-persist disable-weight-rehash Use the f ollowing command line interface to disa ble rehashing on weight change for host-le vel GSLB policy .
ServerIron ADX Global Server Load Balancing Guide 83 53-1002437-01 Weighted distribution of sites with hash-based persist ence 1 Manually forcing rehash for a domain Consider the case where user disab.
84 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying the contents of active RTT cache entries 1 ******************************************************** Client IP address: 30.
ServerIron ADX Global Server Load Balancing Guide 85 53-1002437-01 Affinity 1 Affinity The GSLB affinity feature configures the GSLB Se rverIron ADX to alwa ys prefer a specific sit e ServerIron ADX f or queries fr om clients whose addre sses are within a given IP pref ix.
86 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Affinity 1 • If the reply contains a VIP on the ServerIron ADX associated with the prefix that the client’s IP address is in, the ServerIron ADX places the VIP at the top of the address list in the reply .
ServerIron ADX Global Server Load Balancing Guide 87 53-1002437-01 Affinity 1 The <si-ip-addr > parameter specifies the sit e Ser verIr on ADX’s management IP address. NOTE In either case, the running-config and the star tup-co nfig file ref er to the ServerIron ADX b y its IP address.
88 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 GSLB domain-level affinity 1 Displaying affinity selection counters Y ou can display the number o f times an IP addre ss is selected based on af finity. T o displa y the information, enter the f ollowing command.
ServerIron ADX Global Server Load Balancing Guide 89 53-1002437-01 GSLB domain -level affinity 1 Command line interface Users will now be able t o configure domain-lev el af fi nity gr oups in addition t o the global affinity definitions. The ne w command line interface for the domain-lev el af fini ty feature is described below .
90 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 GSLB domain-level affinity 1 Show commands • “show gslb affinity -group <group-number>” • “show gslb resources” •.
ServerIron ADX Global Server Load Balancing Guide 91 53-1002437-01 DNS cache proxy 1 TCP APP Count (%) * 1.1.1.16: cfg real-ip ACTIVE N-AM 5 17 0 (0%) * 1.1.1.108: cfg v-ip ACTIVE N-AM 0 0 5 (100%) show gslb dns detail Use this command to display the affinity group associat ed with the domain and the number of selections based on af finity .
92 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 DNS cache proxy 1 In configurations where the Ser verIr on ADX and DNS server are co-l ocated, the additional r ound trip time between the ServerIron ADX and DNS se rver is usually negligible.
ServerIron ADX Global Server Load Balancing Guide 93 53-1002437-01 DNS cache proxy 1 • DISABLE (the def ault) • ENABLE Displaying DNS cache proxy statistics The GSLB ServerIron ADX maintains statistics fo r the transparent DNS as well as DNS pr oxy mode query intercept and D NS cache proxy f eatures.
94 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 DNS cache proxy 1 The Direct response field, under “DNS cache pr oxy stat”, lists how many DNS q ueries the GSLB ServerIron ADX has responded t o using the DNS cache pro xy feature inst ead of forwarding the queries t o the DNS server .
ServerIron ADX Global Server Load Balancing Guide 95 53-1002437-01 Transparent DNS query intercept 1 GSLB ServerIron ADX performs GSLB on client qu eries f or IPv4 address records (A recor ds).
96 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Transparent DNS query intercept 1 • Redirect the client queries to a pr oxy DNS server and send the reply unchanged. The ServerIron ADX redirects the client request to the alternate DNS ser ver and sends the response, as is, t o the client.
ServerIron ADX Global Server Load Balancing Guide 97 53-1002437-01 Transparent DNS query intercept 1 Redirecting queries T o configure transparent DNS q uer y intercept t o redirect queries to a pr ox.
98 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Transparent DNS query intercept 1 Use the f ollowing CLI method t o configure this f eature. T o configure the ServerIr on ADX to red irect quer ie s to an alt ernativ e DN S ser ver , enter commands such as the fo llowing: ServerIronADX(config)# source-ip 209.
ServerIron ADX Global Server Load Balancing Guide 99 53-1002437-01 Transparent DNS query intercept 1 This command conf igures a vir tual ser ver that ha s the DNS server’s actual IP address.
100 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Transparent DNS query intercept 1 ServerIronADX(config)# server virtual-name-or-ip dns-intercept 209.
ServerIron ADX Global Server Load Balancing Guide 101 53-1002437-01 Transparent DNS query intercept 1 NOTE For non-direct respond transparent int ercept, you s hould not en able dns transparent-interc ept in the gslb policy .
102 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Enabling DNS request logging 1 For inf ormation about the statisti cs in the DNS cache pro xy stat section , refe r to “Displa ying DNS cache proxy statistics” on page 93 .
ServerIron ADX Global Server Load Balancing Guide 103 53-1002437-01 Enabling DNS request logging 1 Support for the RTT metric When GSLB ran on the MP , the contr oller cached an RTT update only if tha t par ticul ar IP addr ess had made a DNS quer y earlier .
104 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Enabling DNS request logging 1 BP support as GSLB agent If the ServerIron ADX is used as a GSL B agent, the BP synchronizes RTT information collected fr om clients that make T CP SLB connections to the Se r verIro n ADX, to the MP .
ServerIron ADX Global Server Load Balancing Guide 105 53-1002437-01 Enabling DNS request logging 1 The configuration required for the GSLB distribu ted health c heck feature depends on whe ther the GSLB ServerIron ADX and the site ServerIron ADX suppor t the distributed health check f eature or not.
106 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Enabling DNS request logging 1 Enabling the distributed health check feature for an indivi dual site ServerIron ADX Y ou ca n enable the d istributed health chec k feature f or an individual site ServerIron AD X.
ServerIron ADX Global Server Load Balancing Guide 107 53-1002437-01 Enabling DNS request logging 1 T o globally configure the hea lth status repor ting interval, enter commands su ch as the following on the GSLB ServerIr on ADX.
108 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Enabling DNS request logging 1 Impact of distributed health checks on the Flashback metric If the GSLB ServerIr on ADX suppor ts the distribu ted health check feature, then the F lashback metric is disabled b y default in release 08.
ServerIron ADX Global Server Load Balancing Guide 109 53-1002437-01 Enabling DNS request logging 1 Configuration exampl es FIGURE 7 To p o l o gy Example 1 In this example: • The GSLB ServerIron ADX suppor ts the distributed health check f eature. • Site S er v erIron ADXs 1.
110 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Enabling DNS request logging 1 In order to globally configure the hea lth status in terval to 7 seconds, configure the f ollowing on the GSLB ServerIron ADX.
ServerIron ADX Global Server Load Balancing Guide 111 53-1002437-01 Enabling DNS request logging 1 The GSLB ServerIron AD X does not suppor t the dist ributed health check f eature, so the distribut ed health check configuration is neither suppo r ted no r applicable t o the GSLB ServerIron ADX.
112 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 DNSSEC 1 DNSSEC DNSSEC (Domain Name System Secu rity Extensions) is a set of extensions that pr ovide DNS resolvers origin authentication of DNS data, data int egrity and authenticated denial of e xistence.
ServerIron ADX Global Server Load Balancing Guide 113 53-1002437-01 DNSSEC 1 1. LDNS sends a normal type A request with the DO bit set t o the mydnssec.com ADNS 2. If the ADNS support s DNSSEC, the response ha s the DO bit set and a RRSIG record f o r the response RRset in the answer section 3.
114 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 DNSSEC 1 Verification with DIG The f ollowing example show s dig being used to validate a DNSSEC response. DNSSEC GSLB in DNS proxy mode The ServerIron ADX suppor ts GSLB for DNSSEC in the DNS pro xy mode.
ServerIron ADX Global Server Load Balancing Guide 115 53-1002437-01 DNSSEC 1 (IP address) are used in the signature. The TTL s of individual resourc e records are not part of the data used in signing to allow f or aging.
116 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 DNSSEC 1 Configuring load balancing of plai n DNS request across all servers If zones and real ser vers a re configur ed for DNSSEC, then non-dnssec ser vers are used f or requests on non-dnssec zones.
ServerIron ADX Global Server Load Balancing Guide 117 53-1002437-01 Host-level policies for site selection 1 Syntax: show gslb global-statistics Host-level policies for site selection ServerIron ADX p.
118 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Host-level policies for site selection 1 1. Define a name f or the host-lev el GSLB policy . Ref er to page 118 . 2. Configure the parameters fo r the policy. R efer t o page 118 . 3.
ServerIron ADX Global Server Load Balancing Guide 119 53-1002437-01 Host-level policies for site selection 1 Y ou must specify a connection limit to enable th e Connection Load metric. Y ou can speci fy a value from 1 to as high a value as y ou need. There is no def ault.
120 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Host-level policies for site selection 1 Some of the DNS parameters are no t conf igurable in the host-level GSLB policy .
ServerIron ADX Global Server Load Balancing Guide 121 53-1002437-01 Host-level policies for site selection 1 When the ServerIron ADX co mpares the Flashback speeds, it compares the Layer 7 (application-lev el) Flashback speeds firs t, if applicab le.
122 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Host-level policies for site selection 1 GSLB-ServerIronADX(config)# gslb-host-policy abc GSLB-ServerIronADX(config-gslb-host-po.
ServerIron ADX Global Server Load Balancing Guide 123 53-1002437-01 Host-level policies for site selection 1 Enabling the Num-s ession metric The capacity threshold spec ifies how close to the maximum ses sion capacity the si te ServerIronADX (remot e Ser verIr on ADX) can be and st ill be eligible as the b est site f or the client.
124 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Host-level policies for site selection 1 Syntax: [no] round-r obin Enabling the Round-Trip-Time metric Y ou can enable the GSLB metric for the r ound-trip time between the remot e Ser verIr on ADX and the DNS client.
ServerIron ADX Global Server Load Balancing Guide 125 53-1002437-01 Host-level policies for site selection 1 GSLB-ServerIronADX(config)# gslb-host-policy abc GSLB-ServerIronADX(config-gslb-host-policy-abc)# weighted-site Syntax: [no] weight ed-site Use the no f orm of the command to disable the weig ht ed IP metric for the host-level policy .
126 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Host-level policies for site selection 1 Displaying all GSLB policies T o view all defined host-level poli cies, ent er the follo wing command.
ServerIron ADX Global Server Load Balancing Guide 127 53-1002437-01 Host-level policies for site selection 1 Displaying the policy used for hosts T o view which GSLB policy is being used for hosts, ent er the follo wing command. ServerIronADX# show gslb dns zone ZONE: gslb1.
128 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Host-level policies for site selection 1 Deleting GSLB host-level policies Deleting a policy that is not applied to a host Y ou can .
ServerIron ADX Global Server Load Balancing Guide 129 53-1002437-01 Geographic region for a prefix 1 GSLB-ServerIronADX(config-gslb-dns-gslb1.com)# exit GSLB-ServerIronADX(config)# gslb dns zone foo.com GSLB-ServerIronADX(config-gslb-dns-foo.com)# host-info ftp ftp GSLB-ServerIronADX(config-gslb-dns-foo.
130 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Geographic region for a prefix 1 management IP address. If you configure a g eographic prefix entr y that matches the management.
ServerIron ADX Global Server Load Balancing Guide 131 53-1002437-01 Geographic region for a prefix 1 Syntax: [no] geo-prefix { <ipv4-prefix> | <ipv6-prefix> } [asia | eur ope | n-amer ica | s-america | africa] The command configures an as so ciation between a prefix and a geographic location.
132 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Geographic region for a prefix 1 T o view all geographic prefix es on the GSLB ServerIron ADX , enter the fo llowing command. GSLB-ServerIronADX# show gslb cache all geographic user-configured prefix length = 24, prefix = 1.
ServerIron ADX Global Server Load Balancing Guide 133 53-1002437-01 Smoothing mec hanism for RTT measurements 1 The abov e output shows that the geographic lo cation is Asia. The geographic location for 1 0.1 0.1 0.200 is still N or th America (N- AM) be cause it does not match the user -configured geographic prefix.
134 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Smoothing mechanism for RTT measurements 1 This release introduces a new smoothing mechanis m along with a proprietary smoothing algorithm for GSLB RTT measurements to effectiv ely deal with variances in RTT measurements.
ServerIron ADX Global Server Load Balancing Guide 135 53-1002437-01 Smoothing mec hanism for RTT measurements 1 Each successively high RTT sam ple will be graduall y factored int o the existing RTT v alu e using an additive increase. The ramp up fact or spec ifies the step f or the additive increase.
136 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Smoothing mechanism for RTT measurements 1 Syntax: enable-site-rtt-smoothing Disabling enhanced RTT smoothing T o disable enhanced R.
ServerIron ADX Global Server Load Balancing Guide 137 53-1002437-01 Smoothing mec hanism for RTT measurements 1 Specifying the ramp-up-factor The ramp-up f actor specifies the increments in which su ccessively new high RTT samples should be fact ored into the ex isting RTT value.
138 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Smoothing mechanism for RTT measurements 1 Syntax: enable-sim-new- r tt-smooth This command enables enhanc ed RTT smoothing only for simulation purposes.
ServerIron ADX Global Server Load Balancing Guide 139 53-1002437-01 Smoothing mec hanism for RTT measurements 1 RTT state before application of RTT smoothing mechanism: ------------------------------------------------------------------ RTT val = 114, RTT decimal val = 0.
140 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Smoothing mechanism for RTT measurements 1 ---------------------------------------------------------------- RTT value after smoothing = 27, RTT decimal val = 0.
ServerIron ADX Global Server Load Balancing Guide 141 53-1002437-01 Round-trip times 1 GSLB-ServerIronADX(config-gslb-rtt-sim-test)# exit Note that the resulting RTT value obtained after smoothing the f ollowing set of RTT samples (30, 1, 1000,30 ,30,30,30) using the old smoothing me chanism is 90.
142 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Round-trip times 1 c o n f i g u r e d o n t h e r e m o t e s i t e S e r v e r I r o n A D X , t h e p a s s i v e R T T i n f o r m a t i o n i s a l s o g a t h e r e d a n d s e n t out to the GSLB controller .
ServerIron ADX Global Server Load Balancing Guide 143 53-1002437-01 Round-trip times 1 Activ e RTT is alwa ys measured between the Site ServerIron ADX and the client LDNS. This method of measuring RTT enables the GSLB Ser verIr on ADX to use this activ ely gathered RTT e ven if the client and its LDNS do not share the same network prefix.
144 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Round-trip times 1 GSLB ServerIron ADXs on which active RTT gatherin g is enabled is compatible with Sit e Ser verIr on AD X s t ha t ar e ru n ni n g p as s ive RT T g at he r in g, a nd v ic e ver s a.
ServerIron ADX Global Server Load Balancing Guide 145 53-1002437-01 Round-trip times 1 Syntax: [no] gslb active-rtt-gathering Once you ent er this command on the GSLB Server Ir on ADX, the GS LB Ser v.
146 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Round-trip times 1 Configuring active RTT parameters Configuring active RTT query message interval The active R TT quer y message interval ref ers to the time intervals at which the GSLB S er v erIron ADX sends the list of LDNS addresses to the Sit e Ser verIr on ADXs.
ServerIron ADX Global Server Load Balancing Guide 147 53-1002437-01 Round-trip times 1 Configuring the active RTT refresh interval The Site ServerIr on ADX maintains a timestamp for each of the LDNS prefixes in its activ e RTT cache. The time stamp indicat es the last time R TT was probed.
148 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Round-trip times 1 In the exam ple above, assume that the GSLB Serv erIr on ADX is configured as Mode 2. Also assume that this GSLB ServerIr on ADX is pro viding GSLB f or www .foo.com where the IP addresses for this domain are IP-1, IP-2, and IP-3.
ServerIron ADX Global Server Load Balancing Guide 149 53-1002437-01 Round-trip times 1 GSLB-ServerIronADX# configure terminal GSLB-ServerIronADX(config)# gslb policy GSLB-ServerIronADX(config-.
150 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Round-trip times 1 If neither of these co mmands is configured, then the GSLB ServerIron ADX will no t use any DNS probe measure ment repor t ed by the Sit e Ser verIr on ADXs and will use only the RTT values reported by the ICMP pr obe for the best IP address selection.
ServerIron ADX Global Server Load Balancing Guide 151 53-1002437-01 Round-trip times 1 If both the ICM P and DNS fast-aging commands are enabled o n the Site ServerIr on ADX, then failure of either ICM P or DNS probes will quickly age out LDNS prefixes from the active RTT ca che.
152 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Round-trip times 1 Displaying RTT information Displaying the RTT gather ing mechanism T o view the RTT gathering mechanism for a Site ServerIron ADX, ent er the following command on the GSLB ServerIr on ADX.
ServerIron ADX Global Server Load Balancing Guide 153 53-1002437-01 Round-trip times 1 Displaying the active RT T gathering configuration T o view the active RTT gathering configuratio n parameters, enter the f oll owing command.
154 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Round-trip times 1 Displaying the RTT informati on of a client IP address The GSLB ServerIr on ADX maintains a cache of RTT inf ormatio n received fr om the site Ser verIron ADXs through the GSLB pr otocol.
ServerIron ADX Global Server Load Balancing Guide 155 53-1002437-01 Round-trip times 1 This output shows that the prefix 1. 1.0.0, prefix length = 20 was creat ed due to an active R TT update fr om the Site ServerIr on ADX. The primar y RTT repor ted f or this prefix by Sit e Ser verIr on ADX 1.
156 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Round-trip times 1 Displaying the RTT algorithm mode T o display the RTT algorithm mode, ent er the following command.
ServerIron ADX Global Server Load Balancing Guide 157 53-1002437-01 GSLB affinity for high availability 1 GSLB affinity for high availability The GSLB Affinity feature configures the GSLB Se rverIron .
158 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 GSLB affinity for high availability 1 Syntax: [no] gslb ha-group <ServerIron ADX-IP-addre ss-1> <Ser verIron ADX-IP-add res.
ServerIron ADX Global Server Load Balancing Guide 159 53-1002437-01 GSLB affinity for high availability 1 1. Make sure you configure HA groups f or the Ser verIr on ADX.
160 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 GSLB affinity for high availability 1 Syntax: show gslb sit e <site-name > The field "Cfg HA peer" shows the config ured HA pee r Site ServerIron AD X for this Sit e Ser verIr on ADX.
ServerIron ADX Global Server Load Balancing Guide 161 53-1002437-01 GSLB affinity for high availability 1 FIGURE 1 1 GSLB af f inity for HA ServerIron ADX 1. 1. 1. 102 is a GSLB ServerIr on ADX that is pro viding GSLB for domain www .foo.com . One of the IP addresses f or ww.
162 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 GSLB optimization 1 Client LDNS 2. 1. 1.53 sends a DNS request t o GSLB Ser verIr on ADX for www. foo.com . GSLB ServerIron ADX rearranges th e DNS reply as fo llows. 1. It checks if there is any affinity definit ion associated with the client LDNS network.
ServerIron ADX Global Server Load Balancing Guide 163 53-1002437-01 GSLB optimization 1 1. On contro ller , enable VIP list pr ocess optimization by issuing the f ollowing command at global config level.
164 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 GSLB optimization 1 Syntax: show gslb sit e The optimized dist hcheck paramet er in the show gslb site output indicates if V IP list process optimiz ation is enabl ed on ServerIr on ADX.
ServerIron ADX Global Server Load Balancing Guide 165 53-1002437-01 Displaying GSLB information 1 Guidelines and recommendations for using this feature W e recommend that you observe the f ollowi ng g.
166 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB information 1 T o display inf ormation for all the configured sites, ent er the follo wing command at any lev el of the CLI. ServerIronADX(config)# show gslb site SITE: sunnyvale ServerIronADX: slb-1 209.
ServerIron ADX Global Server Load Balancing Guide 167 53-1002437-01 Displaying GSLB information 1 T o display inf ormatio n about the GSLB site call ed “sunnyv ale” and the Ser verIr on ADXs pro viding SLB within those sit es, enter the f ollowing command.
168 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB information 1 Displaying real server infor mation rshow 209. 15 7 .22.209 server real Generally , remote ServerIr on ADXs in a GSLB conf iguratio n are themselves configured with real servers and vir tual ser vers.
ServerIron ADX Global Server Load Balancing Guide 169 53-1002437-01 Displaying GSLB information 1 The GSLB protocol allows y ou to quer y the site ServerIron ADXs for configuration information as well as the session and CPU inf ormation used by the GSLB policy .
170 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB information 1 Displaying DNS zone and hosts T o display inf ormation about the DNS zones and ho st names that y ou hav e configured the GSLB ServerIron ADX t o globally load balance, use either of the f ollowing methods.
ServerIron ADX Global Server Load Balancing Guide 171 53-1002437-01 Displaying GSLB information 1 TA B L E 11 GSLB zone and host application information This field... Displays... ZONE The zone name. Th e name that appears here is th e name you specified when you co nfigured the zone inf ormation.
172 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB information 1 Displaying detailed DNS information Y ou can display all the information display ed by the show gslb d.
ServerIron ADX Global Server Load Balancing Guide 173 53-1002437-01 Displaying GSLB information 1 In this ex ample, Ser verIr on ADX slb-1 is the ac tive Ser verIron ADX f or VIPs 209. 15 7 .22. 100 and 1 09. 15 7 .22. 10 1 and Ser verIr on ADX slb-2 is the default activ e Ser verIr on ADX for VIPs 209.
174 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB information 1 Displaying metric infor mation Y ou can show the f ollow ing informat ion: • The metrics that were used t o select a given sit e as the best site.
ServerIron ADX Global Server Load Balancing Guide 175 53-1002437-01 Displaying GSLB information 1 Displaying the default GSLB policy T o display the d efault GSLB poli cy , enter the f ollowing command.
176 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB information 1 DNS ov erride Indicates whether DNS o verride is enabled. DNS ov erride replaces the addresses in a DNS reply with the “best” address fr om a list of addresses you configure.
ServerIron ADX Global Server Load Balancing Guide 177 53-1002437-01 Displaying GSLB information 1 Displaying the user-configured GSLB policy T o display the user -configured GSLB po licy , enter the f ollowing command.
178 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB information 1 For a description of the inf ormation shown by this command, ref er to “Displa ying the default GSLB policy” on page 17 5 .
ServerIron ADX Global Server Load Balancing Guide 179 53-1002437-01 Displaying GSLB information 1 This example sho ws the RTT prefix cache entr y th at contains site IP address 1 92. 1678.2. 1. The prefix source line indicat es that the prefix ca che entr y that matches the site address w as added statically.
180 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB information 1 Displaying GSLB resources For GSLB parame ters, you can displa y the number of currently configured it ems and the maximum number of items y ou can configure on the ServerIr on ADX.
ServerIron ADX Global Server Load Balancing Guide 181 53-1002437-01 Displaying GSLB information 1 Displaying dynamic server information When you configure GSLB, the Ser verIron ADX creat e s dynamic real ser ver configurations based on the IP addresses the GSLB ServerIr on ADX receives in response t o DNS queries sent to the real DNS ser ver .
182 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB information 1 T o display dynamic ser ver information, enter th e commands sho wn in the follo wing examples. The por tions of the output that are shown in bold type are those of interest.
ServerIron ADX Global Server Load Balancing Guide 183 53-1002437-01 Displaying GSLB information 1 Syntax: show server dynamic vir tual Displaying the port bindings T o display the port bindings the ServerIron ADX cr eates for the dynamically created real servers and vir tual ser vers, enter the f ollowing command.
184 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB information 1 The show ser ver dynamic sessions command pro vides a simple wa y to list the real servers. The output is based on the output for the sho w ser ver sessi ons command.
ServerIron ADX Global Server Load Balancing Guide 185 53-1002437-01 Displaying GSLB information 1 ServerIronADX# show gslb cache all affinity prefix length = 24, prefix = 28.1.1.0, region = N-AM prefix source = affinity, affinity = site: local, ServerIronADX: 1.
186 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 SNMP traps and syslog messages 1 ServerIronADX# show gslb cache 1.1.0.0 smaller-than 24 prefix length = 20, prefix = 1.1.0.0, region = ASIA prefix source = geographic (user-configured), rtt-update, site = local, ServerIronADX = (1.
ServerIron ADX Global Server Load Balancing Guide 187 53-1002437-01 SNMP traps and syslog messages 1 A given do main name can be associat ed with multip le health check TC P or UDP por t s. In that case, the GSLB ServerIr on ADX considers an IP address t o be active only if all its associat ed TCP and UDP por ts pass their health checks.
188 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 GSLB error handling for unsupported DNS requests 1 • The final two GSLB messages in this e xample (the ones nearest the top of the log) indic ate that the site ServerIr on ADXs responded to the La yer 3 health chec k (IP ping).
ServerIron ADX Global Server Load Balancing Guide 189 53-1002437-01 GSLB error handling fo r unsupported DNS requests 1 This process w orks in topologies where the GSLB Ser verIr on ADX front-ends a DNS server . How eve r , not all GSLB topologies require a DNS server .
190 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 GSLB error handling for unsupported DNS requests 1 Error handling response format The GSLB error handling response f ormat complies with RFC 2308, NOD A T A type 3 response. By default, the return cod e (rcode) is noerror .
ServerIron ADX Global Server Load Balancing Guide 191 53-1002437-01 GSLB error handling fo r unsupported DNS requests 1 refused = query refused serv fail = ser ver failure NOTE Do not change the error cod e unless you are absolute ly cer tain of the ef fect of the co nfiguratio n.
192 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 GSLB error handling for unsupported DNS requests 1.
ServerIron ADX Global Server Load Balancing Guide 193 53-1002437-01 Chapter 2 Global Server Load Balancing for IPv6 Global server load balancing for IPv6 overview Global Server Load Balancing (GSLB) e.
194 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Global server load balancing for IPv6 ove rview 2 GSLB for IPv6 feature support In the initial release of GSLB for IPv6, a subset of modes, GSLB policy metrics, and other f e atures and modules are suppor ted.
ServerIron ADX Global Server Load Balancing Guide 195 53-1002437-01 Global server load balancing for IPv6 overview 2 • If the client does not adv er tise EDNS0 header with a buf f er larger than 5 12 bytes, eight IPv6 addresses per host are supported in the response.
196 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Basic GSLB for IPv6 configuration 2 The GSLB contr oller makes decisions based on th e GSLB po licy. In the example abo ve, both th e IPv6 VIPs were healthy , so client was directed to the IPv6 VIP that was geographically closer based on the configured policy .
ServerIron ADX Global Server Load Balancing Guide 197 53-1002437-01 Basic GSLB for IPv6 configuration 2 Configuring the GSLB controller The GSLB ServerIron ADX suppor ts global ser ver load balancing in DNS cache pr oxy with DNS ov erride mode.
198 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Basic GSLB for IPv6 configuration 2 Enabling DNS override DNS ov erride enables you t o configure the GSLB ServerIron ADX to "ov erride" the DNS reply f or a domain and specify the IP addresse s for the domains co nfigured on it.
ServerIron ADX Global Server Load Balancing Guide 199 53-1002437-01 Basic GSLB for IPv6 configuration 2 • FTP : the well-known name f or por t 2 1. (Ports 20 and 2 1 both are FTP por ts but on the ServerIron ADX, the name “FT P” corresponds to por t 2 1.
200 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Basic GSLB for IPv6 configuration 2 The ip-list <ipv6- address> variable sp ecifIes the proxy IPv6 address(es ). Y o u can specify as many pro xy IP addresses as you need. If you specify mu ltiple addresses, separat e each address with a space.
ServerIron ADX Global Server Load Balancing Guide 201 53-1002437-01 Basic GSLB for IPv6 configuration 2 Site ServerIron ADX configuration Enabling the GSLB protocol The GSLB prot ocol is disabled by default on si t e Ser verIr on ADX switches.
202 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Basic GSLB for IPv6 configuration 2 DNS ov erride allows the ServerIr on ADX to replac e the IP address in the DNS reply with the IP addresses you configure for the DNS cache pr oxy .
ServerIron ADX Global Server Load Balancing Guide 203 53-1002437-01 Advanced GSLB conf iguration for IPv6 2 If you ha ve enabled the GSLB pr otocol on the sit e ServerIron ADXs, the GSLB Ser verIr on .
204 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Advanced GSLB configuration for IP v6 2 Configuring GSLB policy metrics for IPv6 The GSLB ServerIron ADX suppor ts global ser ver lo ad balancing of IPv6 addresses in cache pr oxy with DNS ov erride mode.
ServerIron ADX Global Server Load Balancing Guide 205 53-1002437-01 Advanced GSLB conf iguration for IPv6 2 Wei g h te d s i te m et r i c Disabled. When the weig hted IP metric is enabled, the weig hted site me tric is disabled. The w eighted sit e metric is an alternati ve to the w eighted IP metric.
206 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Advanced GSLB configuration for IP v6 2 All of these metrics ha ve def ault values but you ca n change the values if needed. In addition, you can disable in dividual met rics or reo rder them.
ServerIron ADX Global Server Load Balancing Guide 207 53-1002437-01 Advanced GSLB conf iguration for IPv6 2 NOTE Brocade recommends that you alwa ys use the health check as the first metric. Other wise, it is possible that the GSL B policy will not select a “best” choice, and thus send the DNS reply unchanged.
208 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Advanced GSLB configuration for IP v6 2 There are no paramet ers for the least response se lection or r ound robin selection metrics. These metrics are tie-break ers. Only one of them is en abled at a time and the one that is enabled is alwa ys the last metric in the policy .
ServerIron ADX Global Server Load Balancing Guide 209 53-1002437-01 Advanced GSLB conf iguration for IPv6 2 When you configure a Ser verIro n ADX for GSLB, it learns a series of IP addresses fr om its configured DNS real servers. Then it per forms La yer 3, Lay er 4, and if possible, Layer 7 health checks against those IP addresses.
210 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Advanced GSLB configuration for IPv6 2 For e xample, y ou could add the zone gslb.com, a dd the host www within the gslb.
ServerIron ADX Global Server Load Balancing Guide 211 53-1002437-01 Advanced GSLB conf iguration for IPv6 2 The command results in an “IP-address not f oun d f or host-name” error if the IPv6 address specified for the ip-weight parameter w as not used as an argument when you defined the IP list.
212 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Advanced GSLB configuration for IP v6 2 By default, the w eighted sit e metric is disabled. When enabled, it is place d second in the GSLB algorithm, af ter the server (host) health metric .
ServerIron ADX Global Server Load Balancing Guide 213 53-1002437-01 Advanced GSLB conf iguration for IPv6 2 ftp . gs lb .c om VIP 200 1:DB8::2 belongs to New Y ork with a w eight of 30 VIP 200 1:DB8::3 belongs to London with a weight of 20 Suppose that t en DNS requests are made to www.
214 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Advanced GSLB configuration for IP v6 2 The default va lue for the threshold is 90%. Thus a sit e Ser verIr on ADX is el igible to be the best site only if its session utilizati on is below 90%.
ServerIron ADX Global Server Load Balancing Guide 215 53-1002437-01 Advanced GSLB conf iguration for IPv6 2 Use the show gslb dns detail command to vie w the active bindings f or each IP address. Ref er to “Displaying D NS zone and hosts” on page 23 7 fo r s a m p l e o u t p u t .
216 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Advanced GSLB configuration for IP v6 2 ServerIronADX# configure terminal ServerIronADX(config)# gslb dns zone company.com ServerIronADX(config-gslb-dns-company.com)# host-info www http ServerIronADX(config-gslb-dns-company.
ServerIron ADX Global Server Load Balancing Guide 217 53-1002437-01 Advanced GSLB conf iguration for IPv6 2 Configuring a geographic prefix Using the geo-prefix command, you can c onfigure the geographic location of an IP address prefix, or ov erride an existing geographic region f or an IP address prefix by c onfiguring a new one.
218 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Advanced GSLB configuration for IP v6 2 If GSLB default location is not specified and if the requesting client prefix is fr om an unknown geography , then the GSLB controller assigns "nor th-america" as its geography .
ServerIron ADX Global Server Load Balancing Guide 219 53-1002437-01 Advanced GSLB conf iguration for IPv6 2 • Session capacity thresh old : Specifies ho w close to th e maximum session capacity the site Ser verIr on ADX (remot e Ser verIron ADX) can be and still be e ligible as the best site f or the client.
220 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Advanced GSLB configuration for IP v6 2 Y ou can modify the follo wing FlashBack parameters: • Application tolerance • TC P t o l e r a n c e The GSLB ServerIr on ADX uses a tolerance v alue when comparing the FlashBack speeds of different sites.
ServerIron ADX Global Server Load Balancing Guide 221 53-1002437-01 Advanced GSLB conf iguration for IPv6 2 • Y ou can bias a GSLB Ser verIr on ADX that is also configured as a site ServerIr on ADX (fo r locally configured VIPs) to always fa vor itself as the be st site.
222 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Advanced GSLB configuration for IP v6 2 Use the round robin selection metric instead of th e least response selectio n metric when you want to pre vent the GSLB ServerIr on ADX from fa voring ne w or recently recov ered sites over pre viously configured active sites.
ServerIron ADX Global Server Load Balancing Guide 223 53-1002437-01 Advanced GSLB conf iguration for IPv6 2 NOTE Hash-based persist ence is a better choice f or GSLB configurations that utilize two GS.
224 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Advanced GSLB configuration for IP v6 2 No special CLI command s need to be issued on the sit e ServerIron ADX. Specifying sticky se ssion prefix lengths T o create sticky f or a specific group (subnet) of cl ients, configure a different prefix length f or that group .
ServerIron ADX Global Server Load Balancing Guide 225 53-1002437-01 Advanced GSLB conf iguration for IPv6 2 High availability considerations for IPv6 sticky persistence Sticky GSLB enables the GSLB contr oller to return the same IP address if a client sends multiple DNS requests within a configurable period of time.
226 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Advanced GSLB configuration for IP v6 2 T o create site persistence f or a specif ic group (s ubnet) of clients, configure a dif ferent hash-based persistence prefix length f or that group.
ServerIron ADX Global Server Load Balancing Guide 227 53-1002437-01 Advanced GSLB conf iguration for IPv6 2 ServerIronADX(config)# gslb policy ServerIronADX(config-gslb-policy)# hash-persist weighted .
228 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Advanced GSLB configuration for IP v6 2 • <weight> is a value from 0 t o 100. The default v alu e is 1. A weight of 0 implies that the client IP will not be allocat ed any hash buck ets.
ServerIron ADX Global Server Load Balancing Guide 229 53-1002437-01 Advanced GSLB conf iguration for IPv6 2 If u se r co n f ig u re s th i s c o mm a n d, h e o r sh e wi l l h ave to ma n ua l ly r eh a sh a t a l a ter c o nven ie n t t i me .
230 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Advanced GSLB configuration for IP v6 2 A site must pass all applicable Layer 4 and La yer 7 health checks t o av oid being removed.
ServerIron ADX Global Server Load Balancing Guide 231 53-1002437-01 Displaying GSLB for IPv6 configurations 2 • If the host has an IPv6 IP list configured, the Ser verIr on ADX applies GSLB policy t o the addresses on the list and responds with AAAA recor ds.
232 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB for IPv6 configurations 2 Direct response = 0 Query type ANY = 0 Query type A = 56 Query type AAAA = 87 The command .
ServerIron ADX Global Server Load Balancing Guide 233 53-1002437-01 Displaying GSLB for IPv6 configurations 2 DNS active-only Indicates whether the GSLB ServerIron ADX remo ves IP addresses fr om the DNS response i f those add resses fail a health check .
234 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB for IPv6 configurations 2 Displaying the user-configured GSLB policy Use the show gslb policy command to view user -.
ServerIron ADX Global Server Load Balancing Guide 235 53-1002437-01 Displaying GSLB for IPv6 configurations 2 In the following example, the o rder has been c han ged, two of the metrics hav e been disabled, and the administrative pre fer ence has been enabled.
236 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB for IPv6 configurations 2 T o view the results of traffic distribution af ter co nfiguring weighted site metrics, ent er the following command: ServerIronADX(config)# show gslb traffic site SITE: local Weight: 50 * a.
ServerIron ADX Global Server Load Balancing Guide 237 53-1002437-01 Displaying GSLB for IPv6 configurations 2 • Local (weight: 50; Ser verIron ADX: 200 1:db8::1; VIPs: 200 1:db8::180 (HTTP) , 200 1:.
238 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB for IPv6 configurations 2 Output differs depending on the ServerIr on ADX de vice used and the sof tware release installed on the ServerIron ADX. TA B L E 2 3 GSLB zone and host application informat ion This field.
ServerIron ADX Global Server Load Balancing Guide 239 53-1002437-01 Displaying GSLB for IPv6 configurations 2 Use the sho w gslb dns command to vie w information about the distribution of traffic af ter the configuratio n of weighted IP metrics. State The stat e of the server .
240 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB for IPv6 configurations 2 The command can be used with or without the < zone-name > variable, which speci fies a si ngle zone. If this variable is om itt ed, all zones are displa yed.
ServerIron ADX Global Server Load Balancing Guide 241 53-1002437-01 Displaying GSLB for IPv6 configurations 2 Syntax: clear gslb dns zone-name [ <name> ] Rep l ac e <zone -name> with the zone for whic h you want t o clear the DNS selection counte rs.
242 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB for IPv6 configurations 2 For descriptions of the other inf o rmation displa yed by the sho w gslb dns detail command, refer t o “Displaying D NS zone and hosts” on page 23 7 .
ServerIron ADX Global Server Load Balancing Guide 243 53-1002437-01 Displaying GSLB for IPv6 configurations 2 T o display inf ormation for all configured sites, en t er the follo wing command at any le vel of the CLI: ServerIronADX(config)# show gslb site SITE: sunnyvale ServerIronADX: slb-1 209.
244 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Displaying GSLB for IPv6 configurations 2 TA B L E 2 5 Global SLB sit e informatio n This field... Displays... Ser verIron ADX name and IP addre ss F or ea ch Ser verIron ADX, the fir st item of informatio n listed is the name and management IP address.
ServerIron ADX Global Server Load Balancing Guide 245 53-1002437-01 Displaying GSLB for IPv6 configurations 2 Syntax: show gslb sit e [ <site-name > ] The <sit e-name> parameter specifies a site name.
246 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Troubleshooting GSLB for IPv6 configuration s 2 bucket 2: ipv6 2001:db8::150, hit count 0 bucket 3: ipv6 2001:db8::150, hit count 0 .
ServerIron ADX Global Server Load Balancing Guide 247 53-1002437-01 Troubleshooting GSLB for IPv6 configurat ions 2 ********************************************* PAX Mem dynamic real virtual debug inf.
248 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Troubleshooting GSLB for IPv6 configuration s 2 ********************************************* GSLB backend DNS debug information: **.
ServerIron ADX Global Server Load Balancing Guide 249 53-1002437-01 Troubleshooting GSLB for IPv6 configurat ions 2 1/1 #sh debug trace summary Count of log entries in the buffer: 2 1/1 #show debug tr.
250 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 Troubleshooting GSLB for IPv6 configuration s 2.
ServerIron ADX Global Server Load Balancing Guide 251 53-1002437-01 Appendix A Reference Materials RFC IPv4 IPv4 RFC 791 IPv6 IPv6 RFC 2460 DNS The GSLB ServerIron uses the Internet Assigned Nu mber s Authority’s (IANA ’s) IP address prefixes (IPv4 or IPv6) to generat e an init ial static datab ase of geographic prefixes.
252 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 DNS A 1 45.248.0.0/1 4 EUROPE 1 45.252.0.0/15 EUROPE 1 45.254.0.0/16 EURO PE 1 49.202.0.0/15 EUROPE 1 49.204.0.0/16 EURO PE 1 49.206.0.0/15 EUROPE 1 49.208.0.0/12 EUROPE 1 49.224.0.0/12 EUR OPE 1 49.
ServerIron ADX Global Server Load Balancing Guide 253 53-1002437-01 DNS A 1 7 .0.0.0/8 NORTH A MERICA 171 . 1 6 . 0 . 0 / 1 2 EUROPE 1 7 1.32.0.0/15 EUROPE 18.0.0.0/8 NORTH AM ERICA 19.0.0.0/8 NORT H AMERICA 192. 1 06.1 96.0/23 EUROPE 192. 1 62.0.0/16 EURO PE 192.
254 ServerIron ADX Global Server Load Balancing Guide 53-1002437-01 DNS A IPv6 address assignment The initial implementation of GSLB for IPv6 ad dresse s suppor ts user configurable geographi c prefixes as a metric in GSLB policy settings for IPv6 addresses.
ServerIron ADX Global Server Load Balancing Guide 255 53-1002437-01 DNS A 200 1:0A00::/23 RIPE NCC 200 1:0C00::/23 APNIC 200 1:0E00::/23 APNIC 200 1:1200::/23 LACNIC 200 1:1400::/23 RIPE NCC 200 1:160.
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