MPLS Fundamentals

Verifying Number of Bytes Label Switched

One way of tracking the level of traffic switched for a certain LSP is by looking at the accounting in the LFIB for that LSP. The LFIB has a column for Bytes Tag Switched that keeps track of the amount of label switched bytes. This can indicate whether the level of traffic for a certain LSP is anywhere near the level of traffic you expect. If that counter is 0 when you expect it to be far higher than that, the LSP is experiencing a problem. You can also keep an eye on the counter to see if it is increasing when you know that traffic should be passing through on the LSP and hence that a particular top label should be used for forwarding traffic. Example 13-14 shows the output of the LFIB and the accounting ...