We have learned what is ECMP (Equal Cost Multi Path) before. Here, we will talk about ECMP Configuration on Nokia Routers. To explain ECMP better, we will use the below MPLS Topology.
Before configuring ECMP, let’s check the FIB and LDP Bindings. On FIB, only the Best Path exists.
LDP Binding of all the peers are given below.
There is only one Active binding as you can see.
Now, let’s start our ECMP Configuration on Nokia Service Routers example and see the change after our configuration. Above, we saw the tables without ECMP. After the ECMP configuration, we will see tables affected by ECMP.
We will configure ECMP on the global router level. And we will use ECMP for three routers.
Here, we said to our router that, “Use three path for ECMP and divide traffic between them equally.” ECMP Equal Multi Path can be used up to 16 routers.
After our ECMP configuration, our FIB (Forwarding Information Base) will include all of these links and LSP Tunnels are established on all these three links as you can see below. The MPLS traffic will go through all these links.
LDP bindings are still in the table with one difference. Here, the Ingres Label of all these LSPs aresame.
And the most important part. You can see the active LDP bindings below. All the links are active as you can see.