[c-nsp] OSPF equal cost load balancing

CiscoNSP List CiscoNSP_list at hotmail.com
Wed Aug 30 00:58:16 EDT 2017

Hi Everyone,

Have an ASR920 connected to an ME3600 with 2 x 1Gb links with same ospf cost (It was a single 1Gb, but secondary 1Gb was added as utilization was getting close to 1Gb) - Was hoping for at least a partial balance of traffic across the 2 links, but egress from ASR920 to the ME3600(Ingress to customers), we are seeing one of the 1Gb links basically maxing out, and the other doing virtually nothing (10-15Mb/sec)...other direction we are seeing pretty much 50:50 balance across the 2 x 1Gb links....I know per-dest algorithm is used, and know that there are a only few big bandwidth users on the ME3600, but I cant understand why basically "all" of the traffic is going down one link?

Is there anyway to "tweak" the load-sharing of the equal cost paths (I can only see per-dst as an option)

Is a L3 etherchannel going to be any "better" with load-balancing than the current ospf equal cost?  (we have voip running over these links, so want to avoid packet delivery order issues)

Is TE a potential solution in this case?

We cant go 10G unfortunately, as the ME3600's dont have 10G ports unlocked, and they are earmarked for retirement - so stuck with multiple 1G links for a short-term fix 😞

Appreciate any feedback/suggestions.


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