From: Richard Dawe <rich AT phekda DOT freeserve DOT co DOT uk>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Those damn va_list errors
Date: Sun, 30 Jun 2002 20:37:21 +0100
Lines: 34
Message-ID: <3D1F5DF1.92B21343@phekda.freeserve.co.uk>
References: <afd341$2pj$1 AT star DOT cs DOT vu DOT nl> <3d1a7b23 DOT sandmann AT clio DOT rice DOT edu> <1025201969 DOT 276236 AT queeg DOT ludd DOT luth DOT se> <3D1B70F2 DOT 52ED1749 AT phekda DOT freeserve DOT co DOT uk> <1025383681 DOT 113436 AT queeg DOT ludd DOT luth DOT se> <3D1ECAAE DOT 37E88DB4 AT phekda DOT freeserve DOT co DOT uk> <1025439260 DOT 198847 AT queeg DOT ludd DOT luth DOT se> <3D1EF9A2 DOT 2C2BD818 AT phekda DOT freeserve DOT co DOT uk> <afna4r$8o1$1 AT antares DOT lu DOT erisoft DOT se>
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To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

Hello.

Martin Stromberg wrote:
> 
> Richard Dawe (rich AT phekda DOT freeserve DOT co DOT uk) wrote:
> : Your packets may be being dropped, due to their size. Try reducing the MTU
> : on the interface that's connected to the Internet. On Windows this is done
> : by hacking the registry.
> 
> Why? Every other ftp site I've tried doesn't have this problem. (They
> are mostly big, more common ones though.)

Some IP stacks use path and reverse path MTU discovery to work out the largest
packet that it can send between it and other hosts. It's possible that
something between your computer and clio.rice.edu breaks MTU discovery, so
that your computer thinks it can send packets of a certain size. But in
reality something in between drops the packets, because they are too large to
be sent further.

Also reverse path MTU discovery is broken in some operating systems in some
circumstances. One example is Windows 2000, when you're using IPSec (IP
security), where it miscalculates the MTU slightly.

> Wouldn't my ethernet connect speed be effected to the worse if I did?

Maybe slightly.

It depends how much you reduce it to. Use a binary search and ping, to find
the maximum packet size you can send to clio.rice.edu. Set your MTU to that.

Hope that helps, bye,

-- 
Richard Dawe [ http://www.phekda.freeserve.co.uk/richdawe/ ]