3com WX1200 3CRWX120695A User Manual

C

HAPTER

 8: C

ONFIGURING

 

AND

 M

ANAGING

 M

OBILITY

 D

OMAIN

 R

OAMING

An unsuccessful roaming attempt might be caused by the following 
timers. You cannot configure either timer.

„

Grace period — A disassociated session has a grace period of 
5 seconds during which MSS can retrieve and forward the session 
history. After 5 seconds, MSS clears the session, and its accounting is 
stopped. 

„

MAC address search — If MSS cannot find the client’s MAC address 
in a Mobility Domain within 5 seconds, it treats the session as a new 
session rather than a roaming session. 

In contrast, the 802.1X reauthentication timeout period has little effect 
on roaming. If the timeout expires, MSS performs 802.1X processing on 
the existing association. Accounting and roaming history are unaffected 
when reauthentication is successful, because the client is still associated 
with the same MAP. If reauthentication fails, MSS clears the session so it is 
not eligible for roaming. 

If the client associates with the same MAP, the session is recorded as a 
new session. (To change the reauthentication timeout, see “Setting the 
802.1X Reauthentication Period” on page 537.)

To monitor the state of roaming clients, use the display sessions 
network verbose command. For example, the following command 
displays information about the sessions of a wireless client who roamed 
between the ports on a WX switch. 

The output shows that the client SHUTTLE\2\exmpl roamed from the MAP 
connected to port 3 to the MAP connected to port 6 on the same WX, 
and then roamed back to the MAP connected to port 3.

WX1200> display sessions network verbose

User

Sess  IP or MAC

VLAN

Port/

Name

  ID  Address

  Name 

Radio

------------------------------ ----  ----------------- --------------- -----
SHUTTLE2\exmpl

 6* 10.3.8.55

default

 3/1

Client MAC: 00:06:25:13:08:33

GID: SESS-4-000404-98441-c807c14b

State: ACTIVE

(prev AUTHORIZED)

now on: WX 10.3.8.103, AP/radio  3/1, AP 00:0b:0e:ff:00:3a, as of 00:00:24 ago
  from: WX 10.3.8.103, AP/radio  6/1, AP 00:0b:0e:00:05:d7, as of 00:01:07 ago
  from: WX 10.3.8.103, AP/radio  3/1, AP 00:0b:0e:ff:00:3a, as of 00:01:53 ago
1 sessions total

(For more information about this command and the fields in the output, 
see the 

.)