Verifying MPLS labels with CEF

Here is a quick and dirty way to verify that the expected labels are being imposed. This is especially useful within the SP core to verify MPLS LDP behavior and assist in troubleshooting, because we often have an inner and an outer label:

R6#show ip cef vrf blue serial 1/1:0 detail
IP CEF with switching (Table Version 23), flags=0x0
10 routes, 0 reresolve, 0 unresolved (0 old, 0 new), peak 27
14 instant recursive resolutions, 0 used background process
96 leaves, 88 nodes, 95448 bytes, 1498 inserts, 1402 invalidations
0 load sharing elements, 0 bytes, 0 references
universal per-destination load sharing algorithm, id DCD67B0C
6(2) CEF resets, 43 revisions of existing leaves
Resolution Timer: Exponential (currently 1s, peak 2s)
0 in-place/0 aborted modifications
refcounts: 23311 leaf, 23040 node

Table epoch: 0 (10 entries at this epoch)

Adjacency Table has 9 adjacencies
7 IPv4 adjacencies
2 IPv6 adjacencies
10.4.1.2/32, version 20, epoch 0, cached adjacency to Serial1/1:0
0 packets, 0 bytes
via 10.8.1.5, Serial1/1:0, 0 dependencies
next hop 10.8.1.5, Serial1/1:0
valid cached adjacency
172.16.100.0/24, version 22, epoch 0, cached adjacency to Serial1/1:0
0 packets, 0 bytes
tag information set
local tag: VPN-route-head
fast tag rewrite with Se1/1:0, point2point, tags imposed: {28 41}
via 172.31.254.1, 0 dependencies, recursive
next hop 10.8.1.5, Serial1/1:0 via 172.31.254.1/32
valid cached adjacency
tag rewrite with Se1/1:0, point2point, tags imposed: {28 41}