[ILUG] Re: [Q] Max number of TCP(?) packets without waiting for an ACK(?)

[Gavin McCullagh]

Hi,

On Tue, 16 Dec 2008, paul at clubi.ie wrote:

>> have forgotten.   nonetheless, it seems to point the
>> finger at MTU-related issue(s?).
>
> Did you say you were using a VPN?

I think that turned out to be that the two hosts were on a different VLAN.

> Ask your admin if he has set the firewall to filter out ICMP (not a very 
> clueful thing to do - so how come NUIM do it Gavin?). Keep the thick copy 
> of Stevens handy, in case he says yes.

I'm not sure if NUIM do?  I finished as a research student there a year or
so ago.  We were somewhat separated from the main network so I wasn't too
aware if they were ICMP bashers.

Another large NUI college in South Dublin used to block ICMP in all its
forms within their campus.  This was considered a security measure on the
basis that one particularly nasty win-borne worm used to ping hosts before
attacking them.  There was considerable wailing and gnashing of teeth from
those who (as users) occasionally needed to debug network issues, but those
who sat in the (metaphorical) tower could not hear.  That may have changed
since.

Gavin