EIGRP over a vNET trunk

New IOS release 15.x introduced Easy Virtual Network (EVN) functionality to leverage some existing deployment features such as VRF-Lite and QinQ.

Its ease of configuration is a real advantage. The idea is very simple: tag each VRF and trunk them to other vNET routers (PE). We will show an example of how it runs on an EIGRP deployment of CEs connecting to each other through PEs that are vNET routers.

DUAL route FSM Processing of EIGRP Queries

Fig. 1: EIGRP route FSM

An interesting case of how DUAL route FSM operates.

First let’s note that an EIGRP router send a Query to its neighbor to find a better route to a destination that has passed from Passive to Active state; that is actively searching for a new feasible route to a destination that no more satisfies the Feasibility Condition.