Brocade Communications Systems ServerIron ADX 12.4.00 Istruzioni per il montaggio

53-1002437-01

January 2012

ServerIron ADX

Global Server Load Balancing Guide

Supporting Brocade ServerIron ADX version 12.4.00

Brocade, the B-wing symbol, BigIron, DCFM, DCX, Fabric OS, FastIron, IronView, NetIron, SAN Health, ServerIron, TurboIron, and

Wingspan are registered trademarks, and Brocade Assurance, Brocade NET Health, Brocade One, Extraordinary Networks,

MyBrocade, VCS, and VDX are trademarks of Brocade Communications Systems, Inc., in the United States and/or in other

countries. Other brands, products, or service names mentioned are or may be trademarks or service marks of their respective

owners.

Notice: This document is for informational purposes only and does not set forth any warranty, expressed or implied, concerning

any equipment, equipment feature, or service offered or to be offered by Brocade. Brocade reserves the right to make changes to

this document at any time, without notice, and assumes no responsibility for its use. This informational document describes

features that may not be currently available. Contact a Brocade sales office for information on feature and product availability.

Export of technical data contained in this document may require an export license from the United States government.

Brocade Communications Systems, Incorporated

Corporate and Latin American Headquarters

Brocade Communications Systems, Inc.

130 Holger Way

San Jose, CA 95134

Tel: 1-408-333-8000

Fax: 1-408-333-8101

E-mail: inf[email protected] 

Asia-Pacific Headquarters

Brocade Communications Systems China HK, Ltd.

No. 1 Guanghua Road

Chao Yang District

Units 2718 and 2818

Beijing 100020, China

Tel: +8610 6588 8888

Fax: +8610 6588 9999

E-mail: [email protected]

European Headquarters

Brocade Communications Switzerland Sàrl

Centre Swissair

Tour B - 4ème étage

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Switzerland

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Fax: +41 22 799 5641

E-mail: emea-i[email protected]

Asia-Pacific Headquarters

Brocade Communications Systems Co., Ltd. (Shenzhen WFOE)

Citic Plaza

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Unit 1308 – 13th Floor

Guangzhou, China

Tel: +8620 3891 2000

Fax: +8620 3891 2111

E-mail: [email protected]

Document History

Title Publication number Summary of changes Date

ServerIron ADX Global Server Load

Balancing Guide

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Contents

About This Document

Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Supported hardware and software . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Document conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Text formatting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Notes, cautions, and danger notices . . . . . . . . . . . . . . . . . . . . . . x

Notice to the reader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x

Related publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

Getting technical help or reporting errors . . . . . . . . . . . . . . . . . . . . . . xi

Web access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

E-mail and telephone access . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

Chapter 1 Global Server Load Balancing

Global Server Load Balancing overview . . . . . . . . . . . . . . . . . . . . . . . 1

Basic concepts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

GSLB example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

GSLB policy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Minimum required configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Configuring GSLB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Proxy for DNS server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Adding a source IP address. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Configuring real server and virtual server for the DNS server .18

Enabling the GSLB protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Configuring a site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Specifying site locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Specifying GSLB controller locations . . . . . . . . . . . . . . . . . . . . . 21

Configuring a zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Private VIPs for GSLB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Configuring a public IP address for a VIP . . . . . . . . . . . . . . . . . . 27

Private VIP display information . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Configuring GSLB protocol parameters . . . . . . . . . . . . . . . . . . . . . . .29

Secure GSLB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

Initial session key generation . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

RSA challenge dialogue. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

GSLB message content randomization . . . . . . . . . . . . . . . . . . . 58

Configuring secure GSLB. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Regenerating the session keys . . . . . . . . . . . . . . . . . . . . . . . . . .63

Minimum GSLB configuration . . . . . . . . . . . . . . . . . . . . . . . . . . .64

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Site persistence in GSLB using stickiness. . . . . . . . . . . . . . . . . . . . . 64

Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Enabling sticky GSLB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66

Allowing sticky sessions for a specific prefix length . . . . . . . . . 67

Configuring the sticky GSLB session life time . . . . . . . . . . . . . . 67

Displaying current sticky GSLB sessions . . . . . . . . . . . . . . . . . .68

Sticky GSLB counters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Deleting sticky GSLB session for a specific client . . . . . . . . . . .70

Deleting all sticky GSLB sessions . . . . . . . . . . . . . . . . . . . . . . . . 70

Site persistence in GSLB using hashing . . . . . . . . . . . . . . . . . . . . . .70

Enabling hash-based GSLB persistence . . . . . . . . . . . . . . . . . .70

Displaying the hash table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Hashing scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

IP address allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72

IP address failure or removal from domain . . . . . . . . . . . . . . . .72

Rehash: new IP address for a domain or change of state . . . .72

Disabling rehash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73

Hash-persist hold-down: boot up considerations if rehash disabled

Manually forcing rehash for a domain . . . . . . . . . . . . . . . . . . . . 74

Show commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

Weighted distribution of sites with hash-based persistence . . . . . . 76

Overview of distribution of sites with hash-based persistence. 76

Configuring distribution of sites with hash-based persistence.79

Configuring weights for domain IP addresses . . . . . . . . . . . . . . 81

Disabling rehash on introduction of new IP addresses or state

change from down to healthy . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Disable rehash when weight for an IP is changed. . . . . . . . . . . 81

Displaying the contents of active RTT cache entries . . . . . . . . . . . .84

Affinity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85

Defining the affinity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86

Displaying RTT prefix cache entries . . . . . . . . . . . . . . . . . . . . . . 87

Displaying affinity selection counters. . . . . . . . . . . . . . . . . . . . .88

GSLB domain-level affinity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Overview of GSLB domain-level affinity . . . . . . . . . . . . . . . . . . . 88

Command line interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

DNS cache proxy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

Enabling DNS cache proxy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92

Displaying DNS cache proxy state . . . . . . . . . . . . . . . . . . . . . . . 92

Displaying DNS cache proxy statistics . . . . . . . . . . . . . . . . . . . . 93

Combining the DNS cache proxy and DNS override features . . 94

GSLB DNS type any query . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

Transparent DNS query intercept. . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Redirecting queries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Redirecting queries and perform GSLB . . . . . . . . . . . . . . . . . . . 99

Responding to queries directly . . . . . . . . . . . . . . . . . . . . . . . . .100

Displaying transparent DNS query intercept statistics . . . . . .101

Enabling DNS request logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . .102

Distributed health checks for GSLB . . . . . . . . . . . . . . . . . . . . .104

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DNSSEC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112

Verification with DIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114

DNSSEC GSLB in DNS proxy mode . . . . . . . . . . . . . . . . . . . . . .114

Configuring DNSSEC for GSLB . . . . . . . . . . . . . . . . . . . . . . . . .115

Displaying DNSSEC configuration. . . . . . . . . . . . . . . . . . . . . . .116

Displaying DNSSEC statistics . . . . . . . . . . . . . . . . . . . . . . . . . .116

Host-level policies for site selection. . . . . . . . . . . . . . . . . . . . . . . . . 117

Global vs host-level policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Configuring host-level policies . . . . . . . . . . . . . . . . . . . . . . . . .117

Displaying host-level policy information . . . . . . . . . . . . . . . . . .125

Deleting GSLB host-level policies . . . . . . . . . . . . . . . . . . . . . . .128

Configuration example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .128

Geographic region for a prefix . . . . . . . . . . . . . . . . . . . . . . . . . . . . .129

How geographic location is determined . . . . . . . . . . . . . . . . . .129

Configuring a geographic prefix . . . . . . . . . . . . . . . . . . . . . . . .130

Displaying the number of geographic prefixes. . . . . . . . . . . . .131

Displaying information about geographic prefix . . . . . . . . . . .131

Example configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .132

Smoothing mechanism for RTT measurements . . . . . . . . . . . . . . .133

Configuring enhanced RTT smoothing . . . . . . . . . . . . . . . . . . .134

Determining if the new RTT smoothing mechanism is enabled141

Round-trip times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Passive RTT gathering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Active RTT gathering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .142

Support for both active and passive RTT . . . . . . . . . . . . . . . . .143

Active RTT gathering issues and trade-offs . . . . . . . . . . . . . . .144

Enabling active RTT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .144

Discarding passive RTT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145

Disabling passive RTT gathering. . . . . . . . . . . . . . . . . . . . . . . .145

Configuring active RTT parameters. . . . . . . . . . . . . . . . . . . . . .146

Probes for RTT gathering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .149

Active RTT gathering and high availability support . . . . . . . . .151

Displaying RTT information . . . . . . . . . . . . . . . . . . . . . . . . . . . .152

GSLB affinity for high availability . . . . . . . . . . . . . . . . . . . . . . . . . . .157

Configuring an HA group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157

Enabling dynamic detection . . . . . . . . . . . . . . . . . . . . . . . . . . .158

Displaying HA information . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159

GSLB optimization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .162

Optimized VIP list processing . . . . . . . . . . . . . . . . . . . . . . . . . .162

Increased VIP support per site and reduced CPU usage on GSLB

controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .162

Configuration example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .164

Guidelines and recommendations for using this feature . . . .165

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Displaying GSLB information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .165

Displaying site information . . . . . . . . . . . . . . . . . . . . . . . . . . . .165

Displaying real server information . . . . . . . . . . . . . . . . . . . . . .168

Displaying DNS zone and hosts . . . . . . . . . . . . . . . . . . . . . . . .170

Displaying metric information . . . . . . . . . . . . . . . . . . . . . . . . . . 174

Displaying the default GSLB policy . . . . . . . . . . . . . . . . . . . . . .175

Displaying the user-configured GSLB policy. . . . . . . . . . . . . . . 177

Displaying RTT information . . . . . . . . . . . . . . . . . . . . . . . . . . . .178

Displaying GSLB resources . . . . . . . . . . . . . . . . . . . . . . . . . . . .180

Displaying dynamic server information . . . . . . . . . . . . . . . . . .181

Specifying the source IP of probes . . . . . . . . . . . . . . . . . . . . . .184

Displaying information in the prefix cache. . . . . . . . . . . . . . . .184

SNMP traps and syslog messages. . . . . . . . . . . . . . . . . . . . . . . . . .186

Syslog messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .187

Disabling and re-enabling traps . . . . . . . . . . . . . . . . . . . . . . . .188

GSLB error handling for unsupported DNS requests . . . . . . . . . . .188

Default settings for GSLB error handling . . . . . . . . . . . . . . . . .189

Error handling response format . . . . . . . . . . . . . . . . . . . . . . . .190

Disable or re-enabling GSLB error handling. . . . . . . . . . . . . . .190

Configuring the return code . . . . . . . . . . . . . . . . . . . . . . . . . . .190

Viewing error handling statistics . . . . . . . . . . . . . . . . . . . . . . . .191

Clearing the error handling statistics . . . . . . . . . . . . . . . . . . . .191

Chapter 2 Global Server Load Balancing for IPv6

Global server load balancing for IPv6 overview . . . . . . . . . . . . . . .193

GSLB for IPv6 feature support . . . . . . . . . . . . . . . . . . . . . . . . .194

GSLB for IPv6 example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .195

Basic GSLB for IPv6 configuration . . . . . . . . . . . . . . . . . . . . . . . . . .196

Configuring the GSLB controller . . . . . . . . . . . . . . . . . . . . . . . .197

Site ServerIron ADX configuration. . . . . . . . . . . . . . . . . . . . . . .201

Basic configuration example. . . . . . . . . . . . . . . . . . . . . . . . . . .201

Advanced GSLB configuration for IPv6 . . . . . . . . . . . . . . . . . . . . . .203

Configuring GSLB policy metrics for IPv6. . . . . . . . . . . . . . . . .204

Server (host) health metric . . . . . . . . . . . . . . . . . . . . . . . . . . . .208

Weighted IP metric. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .209

Weighted site metric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .211

Session capacity threshold metric . . . . . . . . . . . . . . . . . . . . . .213

Active bindings metric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .214

Geographic location metric . . . . . . . . . . . . . . . . . . . . . . . . . . . .216

Available session capacity metric . . . . . . . . . . . . . . . . . . . . . . .218

FlashBack speed metric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .219

Administrative preference metric . . . . . . . . . . . . . . . . . . . . . . .220

Least response selection metric. . . . . . . . . . . . . . . . . . . . . . . .221

Round robin selection metric . . . . . . . . . . . . . . . . . . . . . . . . . .221

Sticky persistence for IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . . . .222

Hash-based persistence for IPv6 . . . . . . . . . . . . . . . . . . . . . . .225

Weighted hash-based persistence for IPv6 . . . . . . . . . . . . . . .226

Configuring DNS response parameters . . . . . . . . . . . . . . . . . .229

GSLB of ANY queries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .230

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Displaying GSLB for IPv6 configurations . . . . . . . . . . . . . . . . . . . . .231

Show commands for basic GSLB configurations. . . . . . . . . . .231

Show commands for advanced features . . . . . . . . . . . . . . . . .245

Troubleshooting GSLB for IPv6 configurations . . . . . . . . . . . . . . . .246

Appendix A Reference Materials

RFC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .251

IPv4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .251

IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .251

DNS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .251

IPv4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .251

IPv6 address assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . .254

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About This Document

Audience

This document is designed for system administrators with a working knowledge of Layer 2 and

Layer 3 switching and routing.

If you are using a Brocade Layer 3 Switch, you should be familiar with the following protocols if

applicable to your network – IP, RIP, OSPF, BGP, ISIS, IGMP, PIM, DVMRP, and VRRP.

Supported hardware and software

Although many different software and hardware configurations are tested and supported by

Brocade Communications Systems, Inc. for 12.3.00 documenting all possible configurations and

scenarios is beyond the scope of this document.

The following hardware platforms are supported by this release of this guide:

•ServerIron ADX 1000

•ServerIron ADX 4000

•ServerIron ADX 8000

•ServerIron ADX 10K

Document conventions

This section describes text formatting conventions and important notice formats used in this

document.

Text formatting

The narrative-text formatting conventions that are used are as follows:

xServerIron ADX Global Server Load Balancing Guide

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For readability, command names in the narrative portions of this guide are presented in bold: for

example, show version.

Notes, cautions, and danger notices

The following notices and statements are used in this manual. They are listed below in order of

increasing severity of potential hazards.

NOTE

A note provides a tip, guidance or advice, emphasizes important information, or provides a reference

to related information.

CAUTION

A Caution statement alerts you to situations that can be potentially hazardous to you or cause

damage to hardware, firmware, software, or data.

DANGER

A Danger statement indicates conditions or situations that can be potentially lethal or extremely

hazardous to you. Safety labels are also attached directly to products to warn of these conditions

or situations.

Notice to the reader

This document may contain references to the trademarks of the following corporations. These

trademarks are the properties of their respective companies and corporations.

These references are made for informational purposes only.

bold text Identifies command names

Identifies the names of user-manipulated GUI elements

Identifies keywords

Identifies text to enter at the GUI or CLI

italic text Provides emphasis

Identifies variables

Identifies document titles

code text Identifies CLI output

Corporation Referenced Trademarks and Products

Sun Microsystems Solaris

Questo manuale è adatto per i seguenti modelli

Indice

Altri manuali Brocade Communications Systems Interruttore