Re: [c-nsp] Prefer (outbound) certain bgp peer for AS or subnet ?
Hi, with local-pref you can control outgoing traffic for a specific destination. Prefer one of your upstreams based on the source of traffic, you have to use policy-based routing. Regards, Alex Am 16.10.2013 03:49, schrieb CiscoNSP List: Thanks for everyone's responses - Would the following work (Prefer upstream B egress for the subnet in question)? route-map TEST permit 10 match ip address 100 set local-preference 200 neighbor UPSTREAM_B route-map TEST in Cheers. ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] Prefer (outbound) certain bgp peer for AS or subnet ?
On 15/10/2013, at 12:47 PM, CiscoNSP List cisconsp_l...@hotmail.com wrote: Hi, Have 2 BGP peers with upstreams(full tables from each) on an ASR1000, and we are seeing asymmetric routing for an AS (and /24) - Customer believes this is causing performance issues. Egress traffic to this AS + /24 is going via upstream A (As it only has 3 AS's - Upstream B has 4 AS's to this destination), but return traffic is coming in via upstream B. What is the best method to prefer upstream B egress (For AS or /24)? (But still maintain redundancy if upstream B should go down)? How about using a route-map on the upstream B peer to set a higher local-preference for that originating AS (using a as-path access-list) or prefix (using an ip prefix-list)? Tom ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] Prefer (outbound) certain bgp peer for AS or subnet ?
On 15/10/2013 05:17, CiscoNSP List wrote: What is the best method to prefer upstream B egress (For AS or /24)? Asymmetric routing is a normal part of internet operations. It's not clear why your clients are complaining, but if it's purely because the traffic is routed asymmetrically (rather than because of performance problems on the outbound / return paths), they need gentle application of a cluebat. If you want to prefer a specific uplink based on a source address or ASN, then you need to use policy based routing. This is probably a real bad idea for all the usual reasons. On the other hand, if there are good performance reasons to select a specific egress path for one customer, then probably there are good reasons to use that path for all your other customers too. In this case you might want to put in a policy rule to bump your metrics based on an upstream community or prefix list or as path, depending on how granular you want things to be and how much RP CPU you're prepared to sacrifice on the problem. Nick ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] Prefer (outbound) certain bgp peer for AS or subnet ?
Thanks for everyone's responses - Would the following work (Prefer upstream B egress for the subnet in question)? route-map TEST permit 10 match ip address 100 set local-preference 200 neighbor UPSTREAM_B route-map TEST in Cheers. From: cisconsp_l...@hotmail.com To: cisco-nsp@puck.nether.net Date: Tue, 15 Oct 2013 13:17:20 +1100 Subject: [c-nsp] Prefer (outbound) certain bgp peer for AS or subnet ? Hi, Have 2 BGP peers with upstreams(full tables from each) on an ASR1000, and we are seeing asymmetric routing for an AS (and /24) - Customer believes this is causing performance issues. Egress traffic to this AS + /24 is going via upstream A (As it only has 3 AS's - Upstream B has 4 AS's to this destination), but return traffic is coming in via upstream B. What is the best method to prefer upstream B egress (For AS or /24)? (But still maintain redundancy if upstream B should go down)? Cheers ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
