Panasonic NN46240-710 - Manual (Page 94)

Nortel Secure Router 8000 Series
Troubleshooting - VPN___________ 3 BGP/MPLS IP VPN troubleshooting
• An arbitrary IGP runs between PE1, P, and PE2 to transfer routing information of the
public network.
• Both MPLS and MPLS LDP are enabled on PE1, P, and PE2 individually.
Fault symptoms: PE1 has the private network route sent from CE1 while PE2 and CE2 do not
have this route.
Fault analysis
A public network tunnel is a necessity when private network traffic traverses the public network
to the remote. Therefore, you must bind the next hop of the private network route with the LSP
between PEs.
• In the case that LSPs are generated first, the binding between the routes and tunnels exists
in TNLM. According to the IP address of the next hop of the private network route, RM
can search TNLM for the binding.
• When routes are learned first and then LSP tunnels are generated, the TNLM notifies the
RM related information such as the destination IP address of the LSP. According to the
information, the RM finds the associated private network route and performs iteration.
• Use the display ip routing-table vpn-instance command on PE2. If no VPN routes
appear, but the configuration is correct and BGP peers are set up correctly, the possible
cause is that the LSP tunnel is not set up successfully.
• Use the display ip routing-table vpn-instance vpn-instance-name ip-address [ mask |
mask-length ] verbose command on PE1 to view the tunnel ID of the LSP
If the tunnel ID is 0x0, it indicates that the route to ip-address does not find the associated
tunnel. The reason is often that the setup of LSP for the next hop of the route fails.
<PE1> display ip routing-table vpn-instance vpna 10.2.1.202 32 verbose
Destination: 10.2.1.202/32
Protocol: BGP Process ID 0
Preference: 255 Cost 0
NextHop 3.3.3.3 Interface NULL0
RelayNextHop 0.0.0.0 Neighbour 3.3.3.3
Label: 15360 Tunnel ID 0x0
SecTunnel ID 0x0
BkNextHop 0.0.0.0 BkInterface
BkLabel NULL Tunnel ID 0x0
SecTunnel ID 0x0
State: Inactive Adv WaitQ Age 00h01m05s
Tag: 0
Check the LSP to the next hop (3.3.3.3):
<PE1> display mpls lsp include 3.3.3.3 32
If the display is blank, it indicates that no LSP to 3.3.3.3 exists. The LSP is not set up
successfully.
Check whether MPLS LDP is enabled on the interface that connects PE1 and P, and on the
interface that connects P and PE2:
[PE1] interface giggabitethernet 1/0/0
[PE1-Gigabitethernet1/0/0] display this
#
interface Gigabitethernet1/0/0
link-protocol ppp
Issue 5.3 (30 March 2009) Nortel Networks Inc. 3-15