Strange connectivity issue Frontier EVPL

aaron1 at aaron1 at
Fri Nov 6 17:27:06 UTC 2020

EVPL (eline) should not be learning macs.  So mac table size should be a non-issue.  Unless someone somewhere has constructed a 2-part bridge domain (mef-speak, etree or elan of sorts) which would have mac learning, then Matt's question comes into play.


-----Original Message-----
From: NANOG < at> On Behalf Of Matt Hoppes
Sent: Friday, November 6, 2020 11:09 AM
To: Jay Hennigan <jay at>; NANOG list <nanog at>
Subject: Re: Strange connectivity issue Frontier EVPL

Could you be running up against a MAC table limit on the circuit?

On 11/6/20 11:59 AM, Jay Hennigan wrote:
> 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?

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