[c-nsp] A9K-VSM-500

[Jason Lixfeld]

Hey all,

I’ve been reading through some docs on the A9K-VSM and I have some questions that I couldn’t find answers for. I don’t actually own one of these cards, so I can’t really test this for myself.

1. Cisco recommends[1] the default interface MTU on customer-facing interfaces, and to configure the VSM interfaces to 1518.  Does this imply that the VSM doesn’t support > 9000 MTU, such that if the customer side supported 9K MTU and the application connected to the outside interface supported 9K MTU, it’d be frag-city across the VSM?

2. Assuming a customer has their own inside and outside VRFs (as opposed to multiple customer inside VRFs sharing one single outside VRF), I’m assuming there’d be no issues running a routing protocol (ie: BGP) sourced from the IP on the physical interface in the inside VRF towards a neighbor on the opposite end of that inside interface, or sourced from the IP on the physical interface in the outside VRF towards a neighbor on the opposite end of that outside interface, or both?

3. If I can do #2, how would I redistribute routes between the inside BGP session and the outside BGP session when there’s a pair of ServiceApp interface in between the inside PHY interface and the outside PHY interface?  Simple ebgp multi-hop from the inside interface IP to the outside interface IP over the ServiceApp Interfaces?

[1] https://community.cisco.com/t5/service-providers-documents/asr9000-xr-cgv6-on-vsm-cgn-nat44-deployment-guide/ta-p/3154766/page/3/show-comments/true#mtu <https://community.cisco.com/t5/service-providers-documents/asr9000-xr-cgv6-on-vsm-cgn-nat44-deployment-guide/ta-p/3154766/page/3/show-comments/true#mtu>

Thanks in advance for any clue!