Brocade Communications Systems ServerIron ADX 12.4.00 - Manual (Page 236)

224 ServerIron ADX Global Server Load Balancing Guide
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Advanced GSLB configuration for IPv6
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No special CLI commands need to be issued on the site ServerIron ADX.
Specifying sticky session prefix lengths
To create sticky for a specific group (subnet) of clients, configure a different 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.
By default, the ServerIron ADX creates sticky sessions for every IPv6 DNS client with a prefix length
of 128 bits. The ipv6-prefix-length parameter enables you to specify an alternative prefix length.
To specify the prefix length, enter commands such as the following:
SLB-Ctrl-ServerIronADX(config)#gslb policy

SLB-Ctrl-ServerIronADX(config-gslb-policy)#sticky ipv6-prefix-length 64
Syntax: [no] sticky ipv6-prefix-length <decimal >
The ipv6-prefix-length parameter specifies the prefix length of IPv6 DNS clients. The parameter
enables you to aggregate DNS clients into one sticky session. The default prefix length is 128 bits.
NOTE
ServerIron ADX does not support the synchronization of sticky sessions across BPs. With sticky
ipv6-prefix-length configured, DNS requests from clients on the same subnet go to different BPs and
different sticky sessions will be created on different BPs. However, each individual client will receive
the same specific domain IP that it received in its previous DNS request.
Specifying sticky session life times
Sometimes clients do not accept DNS servers, thus creating stale sessions. The sticky GSLB
session life time (age) prevents sessions from hanging for extended periods of time.
By default, the life time (age) of sticky sessions is set at five minutes. Use the sticky age command
to specify the time (in minutes) that must past before an idle session “times out” and session
resources are made available to other clients.
To configure the Sticky GSLB session life time (age), enter commands such as the following:
SLB-Ctrl-ServerIronADX(config)#gslb-host-policy test

SLB-Ctrl-ServerIronADX(config-gslb-host-policy-test)#stick age 5
Syntax: [no] sticky age <value>
The <value> is the number of minutes before sticky session is cleared.
Deleting sticky sessions
The clear gslb ipv6 sticky-session command enables you to clear all sticky sessions or sticky
sessions for a specific client.
Syntax: clear gslb ipv6 sticky-session (all | <client-ip> )
The <client-ip> is the IP address or prefix of the client for which sticky session will be deleted. If the
all option is used, the sticky sessions for all clients are cleared.