Strange connectivity issue Frontier EVPL

Jay Hennigan jay at
Fri Nov 6 16:59:28 UTC 2020

We have a strange issue that defies logic. We have a NNI at our POP with 
Frontier serving as an aggregation circuit with different customers on 
different VLANs. It's working well to several customers.

Bringing up a new customer shows roughly half of the IP addresses 
unreachable across the link, as if there's some kind of load-balancing 
or hashing function that's mis-directing half of the traffic. It's 
consistent, if an address is reachable it's always reachable. If it's 
not reachable, it's never reachable. Everything ARPs fine.

The Frontier circuit is layer 2 so shouldn't care about IP addresses. 
Frontier tech shows no trouble. They changed the RAD device on-premise. 
We've triple-checked configurations, torn down and rebuilt subinterface, 
etc. with no joy.

Any suggestions?

Jay Hennigan - jay at
Network Engineering - CCIE #7880
503 897-8550 - WB6RDV

More information about the NANOG mailing list