A BGP issue?

Viral Vira viraviralh at gmail.com
Tue Mar 8 06:50:57 CST 2011


I have seen this kind of problems in our customers networks and this is
motly related to MTU/MSS. Network reachability is fine but applciations does
not work. Apply the MSS on the LAN interface which is around 100 bytes less
than the MTU on the WAN interface.

-Thanks,
Viral.

On 8 March 2011 16:11, Vadim Antonov <avg at kotovnik.com> wrote:

>  On Tue, 2011-03-08 at 09:25 +0200, Hank Nussbacher wrote:
> > At 21:49 07/03/2011 -0500, Patrick W. Gilmore wrote:
> > >On Mar 7, 2011, at 14:27, Greg Ihnen <os10rules at gmail.com> wrote:
> > >
> > > > I run a small network on a mission base in the Amazon jungle which is
> > > fed by a satellite internet connection. We had an outage from Feb 25th
> to
> > > the 28th where we had no connectivity with email, http/s, ftp, Skype
> > > would indicate it's connected but even chatting failed, basically
> > > everything stopped working except for ICMP. I could ping everywhere
> just
> > > fine. I started doing traceroutes and they all were very odd, all not
> > > reaching their destination and some hopping all over creation before
> > > dying. But if I did traceroute with ICMP it worked fine. Does this
> > > indicate our upstream (Bantel.net) had a BGP issue? Bantel blamed
> > > Hughesnet which is the service they resell. I'm wondering what kind of
> > > problem would let ping work fine but not any of the other protocols. It
> > > also seems odd that I could traceroute via UDP part way to a
> destination
> > > but then it would fail if the problem was my own provider. Thanks.
> > > >
> > > > If this is the wrong forum for this post I'm sorry and please just
> hit
> > > delete. If this is the wrong forum but you'd be kind enough to share
> your
> > > expertise please reply off-list. Thanks!
> > >
> > >Honestly, I would rate this as one of the most on-topic posts in a
> while.
> >
> > +1.
> > When you have http working I suggest running:
> > http://netalyzr.icsi.berkeley.edu/index.html
> > to give you a benchmark of what your connection can do in the way of
> protocols.
> >
> > Regards,
> > Hank
>
>
> Greg - you may want try doing pings with large packets. You may have MTU
> mismatch or some other problem with a link with lets small ICMP pings
> through but mangles or discards large packets.
>
> --vadim
>
>
>



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