Network engineers from the state communicated to me they use BGP.

The Sonic does not use BGP.

The northernlights hop is a good 10 hops away.


The Internet works for all other districts at the same time the sonic 
flips over to the fail-over, with no complaints that specific sites 
cannot be reached.


I can only assume the state really is using BGP. The one constant is the 
school traffic always follows the same path to responder.sonicwall.com



On 01/20/2015 09:19 PM, Justin Krejci wrote:
> Well I guess I would ask how is it you know there is a BGP route 
> change happening? Do you have bidirectional traceroutes? Much of the 
> Internet has asymmetrical routing so even if you don't see a problem 
> or change in one direction that doesn't mean the return path is the 
> same or is problem free.
>
> In general, yes your pings will continue to work under a normal BGP 
> re-routing, you may just see a change in RTT if the new path is faster 
> or slower than the previous one. There is nothing special about plain 
> old pings that would otherwise be affected by a route change.
>
> What could be possible is one router along the problem path has some 
> kind of filter that is filtering pings, doing DPI with some kind of 
> filtering policy, or some other wonky behavior.
>
> It's it clear if the sonicwalls in question are doing BGP or not 
> (sounds like no). It is also not clear of the gigapops hop is the the 
> sonicwalls first hop or not.
>
>
>
> -------- Original message --------
> From: Raymond Norton
> Date:01/20/2015 8:56 PM (GMT-06:00)
> To: TCLUG Mailing List
> Subject: Re: [tclug-list] OT network question
>
>
> > My un-educated answer: it depends.  If the BGP route is the next hop
> > from the machine sending the ping, then yes, you'll probably need to
> > restart.  The ping instance will continue to want to use the broken
> > path as its next hop.  If, however, you're downstream from the BGP
> > route (another hop between you and the BGP router) it shouldn't matter
> > because your machine's next hop wouldn't change.
> >
> > Does that describe the behavior you're seeing?
>
>
> Specifically, this is what we have going: A couple school districts use
> Sonicwall firewalls. The fail-over system does a sustained ping to
> responder.sonicwall.com. The path it takes 100% of the time always hits
> northernlights.gigapop.net (146.57.252.194) and another dozen hops after
> that. The state has been having a lot of difficulty with this hop,
> because of some major routing changes made by the U of M for traffic
> destined to Chicago. Almost all of our districts never know there is a
> problem, because BGP on the state routers finds a better path. However,
> the two districts  (both use sonic) sustained pings insists on using the
> northernlights hop, thus triggering their fail-over circuit, even though
> there is not an actual Internet outage. Just trying to come to a
> definitive reason why this occurs so I can possibly find a fix .
> _______________________________________________
> TCLUG Mailing List - Minneapolis/St. Paul, Minnesota
> tclug-list at mn-linux.org
> http://mailman.mn-linux.org/mailman/listinfo/tclug-list
>
>
> _______________________________________________
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> tclug-list at mn-linux.org
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-- 
Raymond Norton
LCTN
952.955.7766

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