Re: tcpip stops working after some time

[Ken Irving <fnkci@uaf.edu>]

On Wed, Dec 24, 2008 at 02:16:26PM -0800, owens@netptc.net wrote:
> >From: fnkci@uaf.edu
> >>On Wed, Dec 24, 2008 at 10:25:07PM +0200, Micha Feigin wrote:
> >>> Ken Irving <fnkci@uaf.edu> wrote:
...
> >>> > 
> >>> > A too-big MTU setting can give odd results in some cases.
> >>> > 
> >>> 
> >>> but how would it change on a running system?
> >>
> >>It probably wouldn't, but maybe an upstream router could have.  I'm 
> >>just tossing out the idea in the off chance it might apply, given 
> >>that some packets go quickly and others don't.
> 
> AFAIK the MTU is set by the initiator of the IP connection and any
> intermediate router can't change it.

MTU is a property of a link, not of packets; I was suggesting that
perhaps a change occurred in the settings of a router through which
packets are going.  This is probably much ado about nothing, but it
is at least easy to test, e.g., by bringing up the interface with a
lower MTU, and seeing if the problem goes away.  Years ago I had to
mess with this to accomodate a (possibly broken) DSL or ppp interface.
Some of the symptoms described in this thread sounded familiar, e.g.,
sometimes things work great, other times slow or not at all.

Ken

-- 
Ken Irving