Panasonic NN46240-710 - Manual (Page 37)

Nortel Secure Router 8000 Series
Troubleshooting - VPN___________ 1 L2TP troubleshooting
Fault analysis
The establishment of the session indicates that LAC and LNS are reachable. It also indicates
that the request for the connection with the L2TP is initiated. Faults on the LNS may cause the
disconnection of the session.
Enable debugging of the L2TP control on the LNS. By verifying the debugging information,
you can determine whether the session is disconnected when the interface receives the Call
Down message.
When you enable debugging of PPP on the LNS by using the debugging ppp all command,
you can find abnormalities.
*0.2426289 Nortel PPP/8/debug2:Slot=1;
PPP Event:
Virtual-Template1:0 : Ask AAA peer’s IP address
*0.2426417 Nortel PPP/8/debug2:Slot=1;
PPP Event:
Virtual-Template1:0 : WaitPeerIP Timer starting
*0.2426545 Nortel PPP/8/debug2:Slot=1;
PPP Event:
Virtual-Template1:0 : Receive Peer's IP address 0.0.0.0 from AAA
*0.2426705 Nortel PPP/8/debug2:Slot=1;
PPP Event:
Virtual-Template1:0 : WaitPeerIP Timer finished
*0.2426833 Nortel PPP/8/debug2:Slot=1;
The preceding information shows that the interface receives the IP address 0.0.0.0. To check
the configuration, see the procedure in the section “VPDN troubleshooting on the L2TP.” You
can find that the access user is the domain user and no configured address pool is in the
domain. Although the VT is bound with the address pool, the domain user applies for the IP
address from the address pool in the domain. So, when the application for the address and the
IPCP negotiation of the PPP fail, the session is disconnected.
Troubleshooting procedure
Step 1 View the L2TP debugging information to determine that the interface receives the Call Down
information.
Step 2 Viewing the PPP debugging information to determine that the interface does not apply for an
IP address.
Step 3 Based on the configuration in the debugging information, you can find that no address pool is
configured in the domain.
—End
Summary
The cause is a configuration error. To resolve the problem, you need to understand the
differences between common user access and domain user access.
Issue 5.3 (19 January 2009) Nortel Networks Inc. 1-17