Strange connectivity issue Frontier EVPL

Mike Hammett nanog at
Fri Nov 6 20:18:44 UTC 2020

This is my biggest complaint about non-wavelength transport. The provider is overselling a port somewhere in the circuit, unless it's a wave. 

Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 

----- Original Message -----

From: will at 
To: nanog at 
Sent: Friday, November 6, 2020 11:54:53 AM 
Subject: Re: Strange connectivity issue Frontier EVPL 

I have similar Frontier NNI's out of One Wilshire, some 1gig some 10. 

While I haven't seen the half-IP-reachable issue you describe I have spent 
days and days chasing performance issues on them. I finally got gig 
line-rate capable iperf3 boxes at both ends and see distinct differences 
in single-TCP stream performance vs running 3-4 streams, and the difference 
disappears like clockwork at "unbusy hours" (1am-7am) every day. 

After running hundreds of tests and adjusting my buffering and RED on both 
ends of these circuits I just have come to the conclusion that they have 
some LAGs somewhere "in the middle" that get busy during the day, and 
they don't care if I have to run 4 TCP streams to max a 1gig circuit. 

It makes browser-based speedtests look really bad but otherwise the 
circuits are usable. We're trying to replace the worst ones with 
wavelength services. 

-Will Orton 

On Fri, Nov 06, 2020 at 08:59:28AM -0800, 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? 
> -- 
> Jay Hennigan - jay at 
> Network Engineering - CCIE #7880 
> 503 897-8550 - WB6RDV 

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