Re: AGIS Route Flaps Interrupting its Peering?

["Rebecca L. Nitzan" <nitzan () es net>]

Peter et al:

    We too have had nothing but trouble with the netedge boxes
(to mae-east and mae-west).  They are particularly insidious 
when they are "kind of working".  A couple years ago, when traffic 
loads were lower, they seemed to perform well. Does anyone know if
MFS has plans to address this problem?
        
                        -- Becca

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Rebecca L. Nitzan                        Lawrence Berkeley National Lab
Network Engineering Services Group       1 Cyclotron Rd, 50A/3101 MS 50C
ESnet - Energy Sciences Network          Berkeley, CA. 94720
phone: 510-486-6468 fax: 510-486-4300    nitzan () es net
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> Here's some background:
>
> AGIS's router is not colocated at the MAE parking garage, but is in fact
> colocated at WorldCom in downtown Washington DC.  Our bits get from there to
> the MAE via a DS3, and that DS3 is terminated at each end with a device
> called a NetEdge, which does the FDDI to DS3 ATM conversion.
>
> These NetEdges seem to have three different possible operating states:
> completely working (which doesn't happen often enough); broken (often, right
> out of the box); and kind of working (which happens all too often).  This
> third operating state results in some very interesting, possibly misleading,
> and sometimes damaging behavior.  It looks quite similar to the kind of
> behavior you get when you change the MAC layer device but keep the same ip
> address at either of the MAE's: ARP caches get inconsistent, and BGP
> sessions with other routers flop around, leading to routes getting flap
> dampened by those running the appropriate code.
>
>
> Here's what happened:
>
> AGIS's connection to MAE-East experienced one of these kind-of-working
> problems which resulted in the erratic behavior above.  Digex customers
> wishing to reach AGIS customers called the Digex NOC, and the posting which
> started this all was made to the Digex internal news group.  Similarly, AGIS
> customers had problems, and we worked with MFS to get the problem resolved
> (they must have a warehouse full of swapped-out NetEdges at this point).
>
> In the interval, a short-on-facts bozo spit into the wind and got us and
> Digex wet.  I'm in private correspondence with Ed Kern to postmortem the
> situation.
>
>  Peter
>
>
> At 10:25 AM 7/5/96 -0400, Ed Kern wrote:
> > > One key point is that we have not received any complaints or reports
> > > of any sort concerning any perceived issues at mae-east from any
> > > mae-east peers.  Digex made no attempt to contact us.  We were already
> > > working with Advantis on the unreachable issue above, but the first we
> > > heard of the "AGIS attacks mae-east" report was when a Digex customer
> > > sent us a report similar to that forwarded to all of you by Cook.
> >
> > Went into this in the last message...Digex will try and be more
> > proactive with pointing out Agis flapping prefixes in the future.
> >
> >
> > > An appropriate audience would have been the AGIS noc and the Digex
> > > noc.  I think the Cook approach was inappropriate because the issue
> > > was purely between Digex and AGIS until Cook distributed it to the
> > > three widespread mailing lists.
> >
> > I agree..
> >
> >
> > > >   How is the report flawed?
> > >
> > > I see that Ed Kern has already replied indicating that the report was
> > > indeed flawed.  I don't think that there is anything to be gained by
> > > going into further detail.
> >
> > What I was referring to was the internal circulation here...which I was
> > under the impression got to external customers....now im not so
> > sure...
> >
> > The internal report was flawed because it relied to much on source
> > routes and came to some bad conclusions on the internal state of agis.
> >
> >
> > > My key point is that nothing of interest happened.  This was a
> > > non-issue until the misinformation was blasted around the Internet
> > > technical universe.
> >
> > I would argue that the external message that got sent around was
> > misinformation...It was correct information from what the people
> > could see at the time it was released...(lots of dampened prefixes and
> > a down peer)..
> >
> >
> > Ed
>
> _____________________________________________________________________
> Peter Kline  Senior Network Engineer|                    313-730-5151
> AGIS - Internet Backbone Services   |                _Lucem Diffundo_
> Post-Traumatic Success Disorder+    |
> /////////////////////////////////////////////////////////////////////
> You can pretend to care, but you can't pretend to be there.
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