[c-nsp] IOS XE BGP Add-Paths Support for VPNv4 + VPNv6 AFI's

[Mark Tinka]

On 8/30/23 18:24, Mark Tinka wrote:

>
> Actually, different RD's are not a solution for VRF routes leaked into 
> the global table. It will only work for traffic carried inside the VRF 
> domain.
>
> If IOS XE can't support Add-Paths for VPN traffic, direct iBGP 
> sessions may be necessary to workaround this. Ouch!

So this turned out to be a known limitation as described in CSCvn41817.

Basically, IOS XE is unable to advertise capability for Add-Paths for 
VPNv4 and VPNv6 AFI's.

 From IOS XE 17.9.x and later, VPNv4 and VPNv6 supports the "bgp 
additional-paths select" and "bgp additional-paths install" features.

However, neither "bgp additional-paths send receive" nor "advertise 
additional-paths" are supported, making it a fractured and not very 
useful feature.

Mark.