MPLS SR-TE set color on outbound for bgp vpnv4 neighbor

[Wippe]

Does SRv4 support setting color values for BGP vpnv4 neighbor outbound directions？

My experimental results indicate that color values can only be set in the receiving direction

How to do that?

[Harold Ritter]

Hi @Wippe ,

You can do it in both directions. The following document shows how this can be done in the outbound direction.

https://www.cisco.com/c/en/us/td/docs/iosxr/ncs5500/segment-routing/72x/b-segment-routing-cg-ncs5500-72x/configure-sr-te-policies.html

Regards,

[Wippe]

THX for ur answer！

But I am using IOS XE Version 17.6.4，my configuration is as follows:

route-map color-ce2 permit 10
set extcommunity color 2

vrf definition 12
rd 1:1
!
address-family ipv4
import map color-ce2
export map color-ce2
route-target export 1:2
route-target import 1:2

address-family ipv4 vrf 12
neighbor 192.168.12.2 remote-as 2
neighbor 192.168.12.2 activate
neighbor 192.168.12.2 route-map color-ce2 in

These configurations have not taken effect correctly，only the color setting for the inbound direction of the VPNV4 address takes effect

WHY?

[Wippe]

Just to add a little bit

Setting the in direction color in add ipv4 vrf 12 for CE devices is also invalid

only set color for inbound RR takes effect

whether configured in VRF or BGP，outbound configure is always invalid

[Harold Ritter]

Hi @Wippe ,

As far as I know, the only supported way to set the color community in IOS-XE is to set a route-map and apply it on the VPNv4 session (inbound or outbound) as described in the following post:

https://community.cisco.com/t5/mpls/ios-xe-does-not-allow-to-set-colour-community-on-the-pe-ce/td-p/4665506

Regards, 

[Wippe]

I have obtained the desired result for this question. Configuring the import map X in VRF can enable the color value to be applied to the incoming routing direction from VPNV4

Can you answer my other question?

Thx!!!!

[Wippe]

One more question

R1#show segment-routing traffic-eng policy all
Name: sr1357 (Color: 1 End-point: 10.200.0.7)
Owners : CLI
Status:
Admin: up, Operational: up for 169:32:35 (since 11-22 07:58:06.663)
Candidate-paths:
Preference 20 (CLI):
Explicit: segment-list srip12467 (active)
Weight: 1, Metric Type: TE
16002 [Prefix-SID, 10.200.0.2]
16004 [Prefix-SID, 10.200.0.4]
16006 [Prefix-SID, 10.200.0.6]
16007 [Prefix-SID, 10.200.0.7]
Preference 10 (CLI):
Explicit: segment-list sr1357 (inactive)
Weight: 1, Metric Type: TE
16003 [Prefix-SID, 10.200.0.3]
16005 [Prefix-SID, 10.200.0.5]
16007 [Prefix-SID, 10.200.0.7]

When I shutdown all interfaces of 10.200.0.6, this list was still active,causing the problem of path not switching,what should i do?

When I shutdown the lookback interface of 10.200.0.6, this list could be inactive

When I reload the device of 10.200.0.6,this list could be inactive

When I down the power of 10.200.0.6,this list was still active

When I shutdown all interfaces of 10.200.0.6 ,show segment-routing traffic-eng topology ipv4 traffic-eng 10.200.0.6,could still see the information of 10.200.0.6 in R1,why?

[Harold Ritter]

Hi @Wippe ,

> When I shutdown all interfaces of 10.200.0.6, this list was still active,causing the problem of path

> not switching,what should i do?

This is due to the fact that only the first SID is checked for liveliness when you used the SID labels for the explicit path policy (as per slide 22 and 24 in attached presentation). The alternative is to use the SID descriptor (IP address) to configure the explicit path policy.

https://www.segment-routing.net/tutorials/2017-03-06-segment-routing-traffic-engineering-srte/

Regards,