Policy based routing, local traffic ASR IOS-XR

[als95]

How can I aply something like PBR but for the traffic originated from the router interface itself in a multi-homed setup? See the diagram attached.

I have 10.0.0.1/31 configured on TenGigE0/0/0/1. I would like ping replies to ping requests to that IP always returned via the same TenGigE0/0/0/1.

At that moment I receive pings from 192.18.1.1 and bgp table has TenGigE0/0/0/5 a best route. This is not a desired behavior since traffic should be returned via TenGigE0/0/0/1 where 10.0.0.0/31 is located.

Is there a way on IOS-XR to apply Policy Based Routing to locally generated packets?

[David Ruess]

Hello,

You cna try the command:

ip local policy route-map <name>

Then you can also run the debug ip policy to see if your traffic is hitting the local policy or not.

-David

[als95]

There is no ip local policy route-map there.

RP/0/RSP0/CPU0:router19(config)#ip local policy route-map
^
% Invalid input detected at '^' marker.
RP/0/RSP0/CPU0:router19(config)#exit
RP/0/RSP0/CPU0:router19#show version
Wed Jan 3 22:08:07.767 MST
Cisco IOS XR Software, Version 7.4.1

[MHM Cisco World]

https://xrdocs.io/ncs5500/tutorials/acl-based-forwarding-and-object-tracking-for-ncs5xx-and-ncs55xx/

Everything in ios xr is different than other ios. 

Check link about ABF

MHM

[als95]

ABF is ingress mechanism only.

[MHM Cisco World]

friend at least check the link 
you never check it and answer directly 
this same as your issue
https://community.cisco.com/t5/xr-os-and-platforms/local-policy-map-pbr-policy-based-routing-in-ios-xr/td-p/4416012

and see the solution 
Make review next time 
MHM

[als95]

Nothing on that link is about locally generated traffic. ABF is for the TRANSIT INGRESS traffic. My question is about LOCALLY GENERATED EGRESS traffic. 

[MHM Cisco World]

OK, did you try config ABF and test 
match the host <IP from which the ICMP is send> and set the next-hop as you want 
try and share config and result 
MHM

[als95]

And apply that ABF where exactly? Again I'm still talking locally generated traffic.

Again, ABF is INGRESS and TRANSIT, I'm talking about EGRESS and LOCALLY generated.

[MHM Cisco World]

ok what about ePBR?
did you try it
MHM

[als95]

what is ePBR? Any doc about it and how to apply that to locally generated egress traffic? 

[MHM Cisco World]

https://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k-r7-5/ip-addresses/configuration/guide/b-ip-addresses-cg-asr9000-75x/Implementing-policy-based-routing.html

[als95]

Your link about INBOUND aka INGRESS. Again, my question is about LOCAL EGRESS. 

[paul driver]

Hello
Applying PBR doesn't necessary change the how the return traffic is routed meaning you most probably would encounter asymmetric routing unless PBR is applied on the other side of the connection as such you would break network connectivity especially if you have strict uRPF enabled.

If you wish to traffic engineer certain traffic then there are alternatives to PBR , depending on how your network is setup - can you elaborate a bit more on your present network topology?

[als95]

Quite the opposite - I expect symmetric routing. But we can ignore that part for a moment.

Question is still open: how to steer locally generated traffic on IOSXR, i.e. ICMP replies from the router itself.