Access-list Based Forwarding in IOS XR

[manoj.karmacharya]

Topology:
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CE1 <---> PE1 <---> PE2 <---> CE2

Configured as:
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• CE1 [ Linux Box ] has default route to PE1. CE1 is connected to PE1 in default-vrf of PE1.
• MP-BGP configured between PE1 & PE2. 
• CE2 is also a linux box with DNS service & linux router. CE2 is connected to PE2 in vrf VPN01. Route exchanged with eBGP peering. CE2 announced it's Lo0 and default route to PE2
• vrf VPN01 configured in PE1 & PE2. 
• PE2 advertises routes received from CE2 to PE1 via MP-BGP peering. 
• Now, VPN01 RIB in PE1 consist of routes Lo0 of CE2 and default-route

Objective

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Any traffic sourced from CE1 and destined to UDP Port 53 to be redirected to vrf VPN01 by PE1

Can anyone help me to meet objective?

[Peter L]

Hi

Check out this supportforum document regarding ABF on the ASR9K. Think that it will help you getting started with ABF.

https://supportforums.cisco.com/t5/service-providers-documents/asr9000-xr-abf-acl-based-forwarding/ta-p/3153403

Regards Peter

[sbhadrav@cisco.com]

Interfaces/VLANs/VRFs on A9K-PE1 to be forwarded with ABF to IGW1, if IGW1 is to fail or not become reachable, the traffic should then get forwarded to IGW2, the same requirement is present on A9K-PE2. There might be multiple Internet gateways in this network, so it’s important to associate each PE with the primary and secondary IGW. In the examples below we will use the loopback addresses of the IGWs, equally one can use any IP address on the GW. It some designs it might be more suitable to use the IP address of the internet facing interface.