AAh - Thank you James! So the ASR920 will not ECMP over 2 links, it requires 4...that would explain the difference between egress/ingress (and why the 920 is not working particularly well!)
Yes, this is ECMP, not LAG - So changing the load sharing algorithm can only be done globally (As I tried to do it under the individual interfaces, and was only presented with per dst as an option) (config-if)#ip load-sharing ? per-destination Deterministic distribution So, changing globally will potentially cause a service disruption? (May need to do this in maintenance window) - Do you suggest "include-ports" as a possible candidate? #ip cef load-sharing algorithm ? include-ports Algorithm that includes layer 4 ports original Original algorithm tunnel Algorithm for use in tunnel only environments universal Algorithm for use in most environments And yes, we are running MPLS over these links (But not a LAG as mentioned) - So does your comment re MPLS hasting still apply to our setup, or only to a LAG? Thanks again for your response - Extremely helpful! ________________________________ From: cisco-nsp <cisco-nsp-boun...@puck.nether.net> on behalf of James Bensley <jwbens...@gmail.com> Sent: Thursday, 31 August 2017 6:43 AM To: cisco-nsp@puck.nether.net Subject: Re: [c-nsp] OSPF equal cost load balancing I think two layer ECMP links are being used here, both of which are in the IGP. Are you running MPLS over these links too? The ME3600 is able to ECMP over any number of links as far as I know (up to the max, which is 8 or 16) however I think the ASR920 will only ECMP over 4 or 8 links (so not 2 as in your case). This could be the problem here. Could you also try to change the CEF load balancing algorithm (assuming this is ECMP and not LAG, this won't affect a LAG): ASR920(config)#ip cef load-sharing algorithm ? include-ports Algorithm that includes layer 4 ports original Original algorithm tunnel Algorithm for use in tunnel only environments universal Algorithm for use in most environments If it is a LAG then on the ASR920 try to adjust these options: ASR920(config)#port-channel load-balance-hash-algo ? dst-ip Destination IP dst-mac Destination MAC src-dst-ip Source XOR Destination IP Addr src-dst-mac Source XOR Destination MAC src-dst-mixed-ip-port Source XOR Destination Port, IP addr src-ip Source IP src-mac Source MAC If you're running MPLS over the LAG the ASR920 can hash MPLS over the LAG and the ASR920 should hash over 2 links just fine. Cheers, James. _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp cisco-nsp Info Page - puck.nether.net<https://puck.nether.net/mailman/listinfo/cisco-nsp> puck.nether.net To see the collection of prior postings to the list, visit the cisco-nsp Archives. Using cisco-nsp: To post a message to all the list members, send ... 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/
