It was brought to my attention from a customer where redcently deployed Cisco SD-WAN infrastructure.
So, they've started a traceroute from a local LAN segment at the center location, to a remote site LAN segment. Both of initiating and receiving hosts are logically behind the SD-WAN fabric and the traffic passes through it. What they observe is that the penultimate hop in the output of the traceroute is the WAN address of the Edge router.
Now, looking at the configs that the vManager has deployed on the Edge, I could observe the following:
1. The WAN address is configured on interface which is assigned to VPN0
2. There's a Tunnel interface for that particular VPN service, which is configured with "ip unnumbered" borrowing the address from the WAN interface in VPN0.
Given the above, it looks obvious why we observe that behaviour. The question I was asked though was... is this behaviour of the SD-WAN Edge router configurable? Can we change this logic?
