158 ServerIron ADX Global Server Load Balancing Guide
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GSLB affinity for high availability
1
Syntax: [no] gslb ha-group <ServerIron ADX-IP-address-1> <ServerIron ADX-IP-address-2>
Enter the IP address of the two Site ServerIron ADXs in a HA group for <ServerIron
ADX-IP-address-1> and <ServerIron ADX-IP-address-2>. Currently, you can specify only two Site
ServerIron ADXs in a HA group. You can configure as many HA groups as needed, but a Site
ServerIron ADX can only be in one HA group at a time.
You can associate the affinity definition for a client (or client LDNS prefix) with either of the
ServerIron ADXs in the HA group. GSLB ServerIron ADX automatically uses the affinity definition for
both ServerIron ADXs in the HA group.
NOTE
When running a ServerIron ADX with a switch image, the management IP address must be
configured before configuring a local site. This is true for configuring for a fresh box or changing an
IP address.
ServerIronADX# configure terminal
ServerIronADX(config)# gslb site local
ServerIronADX(config-gslb-site-local)# si 1.1.1.102
ServerIronADX(config-gslb-site-local)# exit
ServerIronADX(config)# gslb site test
ServerIronADX(config-gslb-site-test)# si 1.1.1.9
ServerIronADX(config-gslb-site-test)# exit
ServerIronADX(config)# gslb ha-group 1.1.1.102 1.1.1.9
ServerIronADX(config)# gslb affinity
ServerIronADX(config-gslb-affinity)# prefer 1.1.1.9 for 1.1.1.0/24
ServerIronADX(config-gslb-affinity)# end
In this example, the configured affinity definition is used for ServerIron ADX 1.1.1.102 and
ServerIron ADX 1.1.1.9 since they belong to the same GSLB HA group.
Enabling dynamic detection
You can also enable dynamic detection of HA Site ServerIron ADXs on the GSLB ServerIron ADX. If
Site ServerIron ADX-1 and Site ServerIron ADX-2 are in high availability configuration and
distributed health-checking is enabled between the Site ServerIron ADX and the GSLB ServerIron
ADX, then the GSLB ServerIron ADX will be able to dynamically determine that they are an HA pair.
However it will be not be able to dynamically detect these ServerIron ADXs as an HA pair, if one of
the following occurs:
•One of the Site ServerIron ADXs loses connection to the GSLB ServerIron ADX and does not
re-establish connection to the GSLB ServerIron ADX.
•Distributed health checking is not supported or not enabled between the GSLB ServerIron ADX
and these Site ServerIron ADXs.
HA groups should be configured and dynamic detection should be configured only as a backup
mechanism.
NOTE
Dynamic detection is an optional configuration and is not needed when HA groups are configured.
To enable dynamic detection of HA pairs, complete the following tasks.