Symptom
In ISG routed lite-session scenarios where DHCP LQ server does not reply, ISG assumes that the mac-address from the subscriber is 0000.0000.0000.
When multiple sessions are in the case, this may lead to sessions being incorrectly deleted due to "roaming", as ISG may believe that the same mac ("0000.0000.0000") is used by a different IP address, and therefore clear the old session.
In such case, the following debugs will be observed:
(debug ip subscriber err/ev, debug sss err/ev)
Oct 28 12:26:59.947: IPSub: Received DHCP Leasequery Callback
Oct 28 12:26:59.947: IPSub: No Relay info received in DHCP lease query callback
Oct 28 12:26:59.947: IPSub ERROR: No MAC address received in DHCP lease query callback
Oct 28 12:26:59.947: IPSub: ipsub_check_update_session_keys called for session 2801795093
Oct 28 12:26:59.947: IPSub: Session exists for mac 0000.0000.0000 trigger IPv4/IPv6 Keys update for existing session
The radius termination code will be shown as:
Oct 28 12:26:59.949: RADIUS: Acct-Terminate-Cause[49] 6 user-roamed-out [24]
Oct 28 12:26:59.949: RADIUS: Vendor, Cisco [26] 38
Oct 28 12:26:59.949: RADIUS: Cisco AVpair [1] 32 "disc-cause-ext=User Roamed Out"
Conditions
* ISG route lite-session for which DHCP LQ is configured
* AND DHCP LQ does not reply (no LEASEACTIVE returned) for 2 or more sessions
