20
W
IRELESS
LAN S
WITCH
AND
C
ONTROLLER
MSS V
ERSION
3.0 R
ELEASE
N
OTES
Domain can interfere with communication
among the switches. (16910)
If the Mobility Domain contains intermediary switches
or routers that use a router redundancy protocol, WX
switches that communicate through those intermedi-
ary devices might lose communication with one other
due to the way some router redundancy protocols
handle MAC addresses. If this issue occurs, log mes-
sages appear periodically on the seed WX switch indi-
cating that member WX switches are entering or
leaving the Mobility Domain.
Set the FDB timer (default 300 seconds) and the ARP
timer (default 1200 seconds) to the same values on
the WX switches. 3Com recommends using 300 sec-
onds as the value for both timers. To set the FDB
timer, use the
set fdb agingtime
command. To set
the ARP timer, use the
set arp agingtime
command.
Port group in a VLAN running STP can cause
Layer 2 loop when the WX switch is not the root
bridge. (18171)
If you configure a port group containing ports that
are already in a VLAN that is running STP, and you
then add the port group to the VLAN, a Layer 2 loop
can occur in the VLAN. This can occur when the WX
switch is not the root bridge.
Instead of adding the port group’s ports to the VLAN
individually, configure the port group before you add
the groups ports to the VLAN, then add the port
group to the VLAN.
MAP Issues
WX1200 allows configuration of ports 7 and 8 as
MAP access ports. (18280)
Ports 7 and 8 on the WX1200 are uplink ports and do
not support PoE. However, the CLI allows you to con-
figure these ports as MAP access ports, for directly
connected MAPs, with an external PoE source to
power the MAPs. Even though the MAPs boot, clients
associated with the MAPs might not receive network
access. This issue does not occur if the MAPs con-
nected to ports 7 and 8 are configured as Distributed
MAPs.
To use a MAP that is directly connected to port 7 or 8
on a WX1200, configure the MAP as a Distributed
MAP (
set dap
command), not as a directly connected
MAP (
set port type ap
command).
Distributed MAP can change IP addresses during
boot sequence in environments with multiple
DHCP servers. (16499)
To become fully active, a Distributed MAP does a full
restart after downloading its software image. The first
time the MAP is powered up, it sends a DHCP dis-
cover for an IP address, uses DNS to find its config-
ured WX switch, then downloads its software image
from that WX. After downloading the image, the
MAP restarts itself with the downloaded image and
sends a second DHCP discover to again obtain its IP
address. In a network containing more than one
DHCP server, it is possible for the MAP to use one IP
address when downloading the image, but end up
with a second IP address after rebooting the second
