Stumper

Wed Jan 22 01:24:48 UTC 2003

On Tue, Jan 21, 2003 at 08:06:07PM -0500, hc wrote:
> 
> MTU on user-end shouldn't really be an issue here.. B/c if so, then (I 
> am only assuming this) how could they access other sites like yahoo.com, 
> etc? I am sure your web site is no different than other common ones.

Well, you're forgetting that odd things tend to happen if MTU on one
side of the connection doesn't agree with the other side of the
link. (MTU is not a function of the transmitter or the receiver but,
rather, a function of the link you're operating on.) We all know what
kind of screwy things can happen when they disagree. (Try holding a
BGP link up over a connection where they differ... t'ain't easy.)

One other possibility here:

I once had to deal with a problem where a particular link would
receive and send data, apparently, just fine. There were errors
counting up one one end, yes, but slowly enough that it didn't seem to
indicate a real source of a problem. Well, DNS queries would go out
just fine but the responses never made it back over this link. As I
said, once connected via IP instead of domain name, everything seemed
to progress just fine. After much head scratching and a complete
visual inspection of every device in the circuit, turns out that two
pieces of gear in the middle were misoptioned.

Very weird but it did happen.

Not that I suspect that to be the problem here (I'm firmly in the MTU
court on this one until evidence shows otherwise) but it is a
possibility..

-Wayne