MPLS Bytes Label Switched in the LFIB

In an MPLS implementation, when viewing the output of the show mpls forwarding-table command, there is a column headed as Bytes Label Switched, as seen in the example below:

Device# show mpls forwarding-table Local Outgoing Prefix Bytes label Outgoing Next Hop Label Label or VC or Tunnel Id switched interface 16 Aggregate IPv6 0 17 Aggregate IPv6 0 18 Aggregate IPv6 0 19 Pop Label 0 Se0/0 point2point 20 Pop Label 0 Se0/0 point2point 21 Pop Label 0 Se0/0 point2point 22 Aggregate IPv6 5424 23 Aggregate IPv6 3576 24 Aggregate IPv6 2600

This value shows the number of bytes switched with this incoming label. The total value includes the size of the outgoing label and the Layer 2 header as well.

If you see values of 0, this means that this particular label is not being used to switch traffic. Note however that traffic will increase this counter only if the traffic is entering the route labeled. If the traffic is entering on the head end of the LSP, that is, from the customer, and it is plain IP traffic, then CEF switches it, and this value will remain zero.