Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.02.xx and greater

10-10
Redundancy Groups
High Availability for Wireless Services
You cannot enter some commands from the redundancy group configuration
mode context. For example, you cannot configure IP settings and redundancy
group settings. These you must set on members on an individual basis.
If you paste a configuration file into the redundancy group configuration mode
context, the invalid commands simply do not take effect. For example, you
could configure one Wireless Edge Services xl Module with all the settings for
your network. Then you could set up the redundancy group, access the
redundancy group configuration mode context, move to the global configura-
tion mode context, and paste the startup-config of the base module into the
CLI. The other modules in the redundancy group would receive WLAN, radio,
DHCP, and RADIUS settings (as well as others), but each module would keep
its own IP address.
Note At most four managers can access a group’s redundancy group configuration
mode context at once.
For more information on CLI commands, see Appendix A: ProCurve Wireless
Services xl Module Command Line Reference.
Redundancy Group Behavior When a Member Fails
Members of a redundancy group listen for heartbeats from every other mem-
ber. If, over the duration of the hold period, modules miss heartbeats from one
member, standby members load balance the failed member’s RPs among
themselves. If you desire, you can configure adoption preference IDs to
control which of several standby modules adopt particular RPs.
Active members take no action when another member of the group fails
unless, for whatever reason, the standby members fail to adopt the orphaned
RPs. For example, a failed network connection might isolate a standby mem-
ber from the RPs, or manual adoption might be inadvertently enabled on the
standby member. If a redundancy group consists of only active members,
active members can also adopt a failed members’ RPs, load balancing the RPs
among themselves.
When the active member becomes functional again, the standby modules
continue to support the RPs. You can manually force the standby modules to
revert the RPs to the recovered member. You cannot, however, force an active
member to return any RPs that it may have adopted. (See “Reverting RPs
Adopted by a Standby Member to the Active Member” on page 10-33.)