Is eBGP multihop bad practice?
I am working on a network where there is an MPLS WAN where the two main sites peer with eBGP to the ISP routers.
There is also DC to DC Layer 3 link which is causing some problems with routing loops, it has been suggested to change the routing protocol on this link to be BGP also, the suggested plan is to peer loopback to loopback on the DC edge routing devices, however to get this to work I need to set eBGP multihop to be 4 as there are two more hops in the path as the edge routers connect to the site link routers.
This solution works ok and I have set it up in GNS, however I have read that eBGP multihop like this is not really best practice
Can anyone advise what the reasons not to do this would be,
The current setup is the edge routers peer OSPF to the site link routers (isp)
The plan is to keep OSPF running and just use BGP to better control the routing loops.
I am more looking for any reasons why using eBGP multihop is bad practice rather than any in depth WAN designs