MPLS Fast Reroute (RFC4090)

Hello everyone! Today I will continue test with the methods of protection your LSP. I try to combine in this article the other three methods. It's all described in RFC4090, one of them is one-to-one backup method (FRR in terminology Juniper) when PLR computes a separate backup LSP called a detour LSP. In the one-to-one backup method, a label-switched path is established that intersects the original LSP somewhere downstream of the point of link or node failure. A separate backup LSP is established for each LSP that is backed up. About one-to-many (facility backup) I will describe later in this article. The normal is CE1-PE1-PE3-PE6-CE4, on the figure it is marked in red, and detour path will be CE1-PE1-PE4-PE3-PE6-CE4 and marked in green line.

Configuration of PE1 and PE6 the same on both sides, and I will show only PE1 for brevity:

PE1 LSP detail information:

 Traceroute before damage:

On the first figure red star indicates the damage during testing (in our case we just disable interface aside PE1):

And now we see that path have changed through PE4:

And now about one-to-many backup method or facility backup. The facility backup method takes advantage of the MPLS label stack. Instead of creating a separate LSP for every backed-up LSP, a single LSP is created that serves to back up a set of LSPs. We call such an LSP tunnel a bypass tunnel. As with the one-to-one method, there could be as many as (N-1) bypass tunnels to fully protect an LSP that traverses N nodes. However, each of those bypass tunnels could protect a set of LSPs.
I show how to configure facility backup (link protection and node-link protection).
Some change of configuration:

Output of transit LSP PE3:

I won't show of damage case, just believe - all working fine. Node-link protection is useful when you wish to protect LSPs after a supporting node fails. And some output and changes:

And after damage case LSP will go via blue line (on the first figure). Transit LSP:

That's all for today, see you soon!