784 Appendix A:Troubleshooting a WSS
NN47250-500 (Version 03.01)
which use bandwidth. If the observer is present but is not listening to TZSP traffic, the observer continuously sends
ICMP error indications back to the AP. These ICMP messages can affect network and AP performance.
To inform you of this condition, WSS Software generates a log message such as the following the first
time an ICMP error message is received following the start of a snoop filter:
AP Mar 25 13:15:21.681369 ERROR AP 3 ap_network: Observer
10.10.101.2 is not accepting TZSP packets
To prevent ICMP error messages from the observer, Nortel recommends using the Netcat application on
the observer to listen to UDP packets on the TZSP port.

Configuring a snoop filter

To configure a snoop filter, use the following command:
set snoop filter-name [condition-list] [observer ip-addr]
[snap-length num]
The filter-name can be up to 15 alphanumeric characters.
The condition-list specifies the match criteria for packets. Conditions in the list are ANDed. Therefore, to be copied and
sent to an observer, a packet must match all criteria in the condition-list. You can specify up to eight of the following
conditions in a filter, in any order or combination:
frame-type {eq | neq} {beacon | control | data | management | probe}
channel {eq | neq} channel
bssid {eq | neq} bssid
src-mac {eq | neq | lt | gt} mac-addr
dest-mac {eq | neq | lt | gt} mac-addr
host-mac {eq | neq | lt | gt} mac-addr
mac-pair mac-addr1 mac-addr2
direction {eq | neq} {transmit | receive}
To match on packets to or from a specific MAC address, use the dest-mac or src-mac option. To match on both send
and receive traffic for a host address, use the host-mac option. To match on a traffic flow (source and destination MAC
addresses), use the mac-pair option. This option matches for either direction of a flow, and either MAC address can be
the source or destination address.
If you omit a condition, all packets match that condition. For example, if you omit frame-type, all frame types match the
filter.
For most conditions, you can use eq (equal) to match only on traffic that matches the condition value. Use neq (not
equal) to match only on traffic that is not equal to the condition value. The src-mac, dest-mac, and host-mac conditions
also support lt (less than) and gt (greater than).