WESM zl Management and Configuration Guide WT.01.28 and greater

10-6
Redundancy Groups
High Availability for Wireless Services
Adopting RPs in Standby Mode
In standby mode, a redundancy group member adopts RPs only in certain circum-
stances:
■ The standby member does not receive a heartbeat from an active member for the
length of time specified in the hold period option.
In a group with multiple active members, the standby member takes action
should even one member fail.
■ All active members fail to adopt an RP, although the group has enough RP
licenses to adopt the RP.
Table 10-1 describes some of these situations.
Table 10-1. Situations in Which a Standby Member Adopts RPs
If the active member becomes unavailable and a standby member adopts its RPs, the
standby member continues to support these RPs even after the active member
becomes available again, which maintains continuity of service. You can, however,
manually revert the standby member to force it to return the RPs to the active member.
RP Licensing for Redundancy Groups
The sections above described the circumstances in which a member of a redundancy
group can adopt an RP. A final condition for adopting an RP is that the group have
sufficient licenses. (See “Radio Port Licenses” on page 2-122 of Chapter 2: “Config-
uring the ProCurve Wireless Edge Services zl Module.”)
The number of licenses for the redundancy group equals the number of licenses
installed on the group member with the most licenses. For example, a group includes
these members:
■ one Wireless Edge Services zl Module with the default license (for 12 RPs) and
one additive license (for 12 RPs)
Situation Possible Causes
A standby member misses
heartbeats from an active member.
• The active member has failed.
• The wireless services-enabled switch in which the
active member is installed has failed.
• A failed network connection has isolated the
wireless services-enabled switch from the network.
Active modules fail to adopt an RP. • Active members’ internal downlink ports have not
been tagged for the RP VLAN.
• Active members’ are explicitly prohibited from
adopting the RP.