[c-nsp] IOS-XR and PBR

Oliver Boehmer (oboehmer) oboehmer at cisco.com
Thu Sep 11 02:09:50 EDT 2014

>I am looking to setup some policy based routing on an IOS-XR router. From
>what I understand, XR does not have PBR, but ABF. When looking at how ABF
>works, I don¹t see how to set a next hop route (only next hop per TCP

well, you can direct any traffic matching an ACE (be it layer 3 or 4) to a
chosen next-hop.

>My question then would be, how does one accomplish this on XR? What
>I need to do is allow a particular IP block to only have access to one of
>our backbone carriers and not the others. We have their /24 only announced
>out the one carrier, but for outbound traffic, I want to make sure their
>traffic remains on that carrier but also have access to our local routes
>(all our local customers and local networks). Is this something that can
>done with ABF 

Yes, it can be done, but possibly a bit more difficult:

ipv4 access-list ABF
 permit CUST/24 <your-own-netblocks>
 permit CUST/24 next-hop <your-upstream-provider>

not sure how your topology looks and where you would need to apply this
forwarding rule, but the next-hop can be directly connected or resolve via
some form of tunnel (including LDP/LSP).


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