105
Perform the
display mpls te tunnel
command on Switch A. You can see that two tunnels are present
with the outgoing interface being VLAN-interface 1 and VLAN-interface 4 respectively. This
indicates that a backup CR-LSP was created upon creation of the primary CR-LSP.
[SwitchA] display mpls te tunnel
LSP-Id Destination In/Out-If Name
1.1.1.9:6 3.3.3.9 -/Vlan1 Tunnel1
1.1.1.9:2054 3.3.3.9 -/Vlan4 Tunnel1
Perform the
display mpls te tunnel path
command on Switch A to identify the paths that the two
tunnels traverse:
[SwitchA] display mpls te tunnel path
Tunnel Interface Name : Tunnel1
Lsp ID : 1.1.1.9 :6
Hop Information
Hop 0 10.1.1.1
Hop 1 10.1.1.2
Hop 2 2.2.2.9
Hop 3 20.1.1.1
Hop 4 20.1.1.2
Hop 5 3.3.3.9
Tunnel Interface Name : Tunnel1
Lsp ID : 1.1.1.9 :2054
Hop Information
Hop 0 30.1.1.1
Hop 1 30.1.1.2
Hop 2 4.4.4.9
Hop 3 40.1.1.1
Hop 4 40.1.1.2
Hop 5 3.3.3.9
Perform the
tracert
command to draw the picture of the path that a packet must travel to reach the
tunnel destination.
[SwitchA] tracert –a 1.1.1.9 3.3.3.9
traceroute to 3.3.3.9(3.3.3.9) 30 hops max,40 bytes packet
1 10.1.1.2 25 ms 30.1.1.2 25 ms 10.1.1.2 25 ms
2 40.1.1.2 45 ms 20.1.1.2 29 ms 40.1.1.2 54 ms
The sample output shows that the current LSP traverses Switch B but not Switch D.
Shut down VLAN-interface 2 on Switch B. Perform the
tracert
command on Switch A to draw the
path to the tunnel destination. The output shows that the LSP is re-routed to traverse Switch D:
[SwitchA] tracert –a 1.1.1.9 3.3.3.9
traceroute to 3.3.3.9(3.3.3.9) 30 hops max,40 bytes packet
1 30.1.1.2 28 ms 27 ms 23 ms
2 40.1.1.2 50 ms 50 ms 49 ms
Perform the
display mpls te tunnel
command on Switch A. You can see that only the tunnel
traversing Switch D is present:
[SwitchA] display mpls te tunnel
LSP-Id Destination In/Out-If Name
1.1.1.9:2054 3.3.3.9 -/Vlan4 Tunnel1