<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></head><body >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. <div><br></div><div>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.</div><div><br></div><div>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.</div><div><br></div><div>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.</div><div><br></div><br><br><div>-------- Original message --------</div><div>From: Raymond Norton <admin@lctn.org> </div><div>Date:01/20/2015 8:56 PM (GMT-06:00) </div><div>To: TCLUG Mailing List <tclug-list@mn-linux.org> </div><div>Subject: Re: [tclug-list] OT network question </div><div><br></div><br>> My un-educated answer: it depends. If the BGP route is the next hop<br>> from the machine sending the ping, then yes, you'll probably need to<br>> restart. The ping instance will continue to want to use the broken<br>> path as its next hop. If, however, you're downstream from the BGP<br>> route (another hop between you and the BGP router) it shouldn't matter<br>> because your machine's next hop wouldn't change.<br>><br>> Does that describe the behavior you're seeing?<br><br><br>Specifically, this is what we have going: A couple school districts use <br>Sonicwall firewalls. The fail-over system does a sustained ping to <br>responder.sonicwall.com. The path it takes 100% of the time always hits <br>northernlights.gigapop.net (146.57.252.194) and another dozen hops after <br>that. The state has been having a lot of difficulty with this hop, <br>because of some major routing changes made by the U of M for traffic <br>destined to Chicago. Almost all of our districts never know there is a <br>problem, because BGP on the state routers finds a better path. However, <br>the two districts (both use sonic) sustained pings insists on using the <br>northernlights hop, thus triggering their fail-over circuit, even though <br>there is not an actual Internet outage. Just trying to come to a <br>definitive reason why this occurs so I can possibly find a fix .<br>_______________________________________________<br>TCLUG Mailing List - Minneapolis/St. Paul, Minnesota<br>tclug-list@mn-linux.org<br>http://mailman.mn-linux.org/mailman/listinfo/tclug-list<br></body>