Meraki SD-WAN routing issue

[ramk]

Is there any option in Meraki to influence or set condition to choose eBGP routes over iBGP. We are running a problem on spoke location where the iBGP routes over shortest ASPATH are chosen, we need to manipulate the routes so that eBGP routes should be preferred. 

[Bruce]

The BGP implementation on Meraki MX is intended only for the routing within SD-WAN. It is intended to use iBGP over the WAN component, and then eBGP from a VPN concentrator head-end to the Data Centre core. If you are using BGP on the MXs for anything other than this it is likely unsupported. I don’t know of any way to influence eBGP over iBGP routes, although given that the iBGP runs over the AutoVPN, and the eBGP directly on the WAN port, I’d need a bit more information as to what you’re trying to achieve.

[ramk]

Hi Bruce,

We need to build the geo regional hub and point the site closer to geo hub with back up hub option.... These Hub's will be connecting to nearest datacenter on MPLS link with eBGP configured. 

All the HUB's will be connected over the SD-WAN so they will exchange routes with iBGP.

What we see is when traffic get advertised from eBGP to HUB location it has longest AS path, where as iBGP within SD Wan has lowest AS path. 

We want to prefer the eBGP to reach data center networks, May I know is there any possibilities to achieve this!

[Bruce]

I’m not sure that I fully understand what you are trying to achieve, can you provide a diagram?

Fundamentally the iBGP within the SD-WAN only passes routes within the SD-WAN, as the SD-WAN is an Autonomous System. The routes passed to your hub from the SD-WAN will be via eBGP since the hub will be a separate Autonomous System, your MPLS network to your data centre will likely be another Autonomous System, as will the data centre itself. You may be able to manipulate the ASPATH attribute on your hub BGP router, but I can’t see how you intend to use the SD-WAN.