Brocade Communications Systems 12.4.00 manual Weighted hash-based persistence for IPv6

2 Advanced GSLB configuration for IPv6

To create site persistence for a specific group (subnet) of clients, configure a different hash-based persistence prefix length for that group. Once configured, the GSLB controller will ensure that DNS clients within the same subnet will be served the same IP address in the GSLB response so long as the IP address belongs to the domain and is active.

To specify the prefix length, enter commands such as the following:

ServerIronADX(config)#gslb policy

ServerIronADX(config-gslb-policy)# ipv6-prefix-len-hash-persist 64

Syntax: [no] ipv6-prefix-len-hash-persist <decimal >

The ipv6-prefix-len-hash-persistparameter specifies the hash-based persistence prefix length of IPv6 DNS clients. The parameter enables you to aggregate DNS clients to go to one domain IP. The default prefix length is 128 bits.

Manually forcing a rehash for a domain

The clear gslb ipv6 phash command enables you to clear the hash tables related to IPv6 addresses.

To force a rehash of a persistent GSLB table, enter a command such as the following:

ServerIronADX# clear gslb ipv6 phash table all

Syntax: clear gslb ipv6 phash table [all zone-name <zone-name>host-name <host-name>]

Use the clear gslb ipv6 phash counter command to clear GSLB phash counters. For more information see “Clearing GSLB phash counters” on page 246.

Weighted hash-based persistence for IPv6

Weighted hash-based persistence allocates the hash buckets in a weighted round robin fashion, enabling you to not only maintain persistence, but also determine what percentage of the traffic goes to a particular domain IP address.

With weighted hash-based persistence, you can define hash weights for the IPs in a domain. The hash buckets are distributed among the domain IP addresses in proportion to these weights.

NOTE

All of the commands used to configure hash-based persistence IPv6 are also applicable to weighted hash based persistence.

Enabling weighted hash-based GSLB persistence

Weighted hash-based GSLB persistence can be enabled for all domains or for specific domains as needed. You can enable weighted hash-based persistence as the global or host-level policy. As a result, this feature applies to all the domains this policy is bound to.

NOTE

Weighted hash-based persistence cannot be enabled concurrently with sticky persistence in the same policy. However, you can enable sticky persistence for one policy and weighted hash-based persistence for another policy.

To enable weighted hash-based persistence globally, enter commands on the GSLB controller, such as the following:

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