BGP ECMP with different BGP next-hop iBGP distances.

[Devrim.Celik]

Hello,

I am currently looking into BGP multipath. Once enabled, the way I understand it, router advertisements to the same prefix are candidates for BGP multipath. For load-balancing to occur, the weight, MED, local pref, AS_PATH, and iBGP distance to the BGP next-hop have to be identical. Is it possible to disable the check for identical distance to the BGP next-hop?
I found out that it is possible to do so with unequal-cost multipath (via BGP Bandwidth Link), but I'd like to have and equal distribution of traffic.

Thank you in advance and apologies for any wrong assumptions I make. I am quite new to this

[balaji.bandi]

Do you have control over other side ? same ISP or different ISP ?

Check some examples:

https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13762-40.html

[Devrim.Celik]

Yes, I do. In which way does that make a difference?
Thanks for the resource! I'll have a look at it.

[MHM Cisco World]

Try 

Bgp bestpath igp-metric ignore,

See result BUT still bgp select one path.

You need multi-path ibgp to make bgp use both path.

[Devrim.Celik]

Thank you, that will be very useful.
I do understand right, that this will also influence the normal BGP decision process, right? There is no way of only influencing the multipath decision process I guess.

[MHM Cisco World]

Bgp w/o multipath ibgp

Bgp select best path send it to other bgp peer 

Bgp use this best path in routing table

Bgp w multipath ibgp

Bgp select best path send it to other bgp peer 

Bgp use both identical path in routing table,

Here you need to ignore igp-metric 

[Devrim.Celik]

But if I enable igp-metrics for the purpose of multipathing, this also does influence all the decisions for the best path in general, right? There is no way of only ignoring it for multipath decisions but still using it for the best-path decision process?

[MHM Cisco World]

Yes you are right if we ignore igp-metric then the BGP will use both path inject into routing table BUT not use it for best-path, 
best-path then will compare the Router-ID to select the best-path.
so you can workaround this by asking Router-ID for path you want more prefer than other path.

[MHM Cisco World]

any update friend ? can you draw topology ?