IOS XE does not allow to set Colour community on the PE - CE session

[shreerampardhy]

Hi All, 

I am using 17.03.04a on IOS XE. Currently i noticed that the colour community can only be set on teh vpnv4 session and not on the inbound session with the CE router. This is in contrast with what IOSXR can do ( colour community can be set on routes received from the customer vrf allowing very granular level of settings ). Does anyone know if the IOSXE has this feature on the roadmap to allow the bgp colour community to be set on the ingress of the PE router?

My requirement is to have allow two separate customers who are using same ip address to have different colours assigned to them. This is easily achievable in IOSXR as the community can be set at the vrf level. Not sure how to achieve that on the XE router.

[Harold Ritter · Accepted solution]

Hi @shreerampardhy ,

I am not sure when that feature will be available in XE, but in the meantime you can configure a route-map on the vpnv4 neighbour that will achieve what you want:

route-map test permit 10
match ip address prefix-list customer1
match extcommunity customer1
set extcommunity color 100
route-map test permit 20
match ip address prefix-list customer2
match extcommunity customer2
set extcommunity color 200
route-map test permit 30

!
ip extcommunity-list expanded customer1
10 permit RT:<customer 1 export RT>

!
ip extcommunity-list expanded customer2
10 permit RT:<customer 2 export RT>

!

ip prefix-list customer1 seq 5 permit <customer1 prefixes>

!

ip prefix-list customer2 seq 5 permit <customer2 prefixes>

Regards,

[shreerampardhy]

Many thanks for the update, Harold. I agree that your solution would be the way to go on IOS XE. 

I was thinking of adding tags to customer routes being received on PE - CE sessions and then matching on those tags to assign them colors while advertising towards remote PEs. That way, i thought, i could go down more granular level by assigning specific set of customer routes with color matching lower latency and keeping rest of customer routes on default igp shortest path colour. 

eg - Assign CustomerA Routes X, Y and Z with tag AS:LowLatency and

Assign CustomerA routes A,B,C with tag AS:NormalRoutes

Same to other customers but with different tags.

Then towards the VPNV4 session use route-map to match on those tags and set colors.

[Harold Ritter · Accepted solution]

Hi @shreerampardhy ,

You will not be able to set tags on BGP routes received from customers, as this is not a supported BGP attributes, but you could certainly use communities to achieve the same. You could have the customer set the community for a specific route and set the color by matching on this community in the outbound route-map towards the VPNv4 core. This way you could have many different colors for a given customer based on the community value set for each route they send you.

Regards,

[shreerampardhy]

you are correct Harold. I realized that and ended up using communities instead.  So the flow is as you mentioned above -

access side  - Communities attached to the IP routes...

towards the core - use match statements to identify the communities and assign colours.