Usage Scenario
In dual-link cold
backup or hot standby scenarios, an AP simultaneously sets up active
and standby links with active and standby ACs, respectively. If the
active link is faulty, the AP switches service traffic to the standby
link and goes online on the standby AC. When the active link recovers,
the AP detects that this link has a higher priority than the other
one and triggers a revertive switchover. After 20 Echo intervals,
the AP switches service traffic back to the active AC.
- To enable an AP to preferentially switch service traffic to the
active link, set the active/standby link switchover mode to the priority
mode.
- To allow an AP to use a link with high network stabilization,
set the active/standby link switchover mode to the network stabilization
mode. When the condition for triggering an active/standby link switchover
is met, the AP preferentially switches service traffic to the link
on a network with higher stabilization. In this case, whether an active/standby
link switchover is performed is only related to the network stabilization
of links but not related to the active and standby roles of links.
You can run the ac protect link-switch packet-loss { gap-threshold gap-threshold | start-threshold start-threshold }
command to configure the condition for triggering an active/standby
link switchover.
In N+1 backup scenarios, APs set up links
only with the primary ACs. When a link between an AP and a primary
AC fails, the AP sets up a link with the backup AC and goes online
on the backup AC. When the primary AC is recovered, a revertive switchover
is triggered. The AP switches the link back to the primary AC after
20 Echo intervals.
- To enable an AP to preferentially go online on the primary AC,
set the active/standby link switchover mode to the priority mode.
- To allow an AP to use a link with high network stabilization,
set the active/standby link switchover mode to the network stabilization
mode.
Precautions
The active/standby link switchover
mode applies to active and standby ACs configured using the ac protect protect-ac and priority commands, or the primary-access and backup-access commands.