🚀 go-pugleaf

> I have tried passive and non-passive modes, 3 different FTP clients
> and even used the web based FTP portal http://www.freewebftp.com and
> nothing works via my EasyNet ADSL connection. Yet I can successfully
> FTP upload to any one of half a dozen other web servers which I run
> sites on (unix and NT).
> 
> Curiously, a colleague can FTP upload fast and without problems from
> his TeleWest Cable Modem connection

It may be interesting to see if the problem exists with other ADSL
providers on IPStream network connections (unlike cable modems, your
packets are tunnelled across BT's network to the ISP - I suspect there
might also be differences in how fragmentation is handled).

> I'm stumped - any suggestions what/where the problem may be and how to
> resolve this?

Might be a bit of a long shot, but you could try reducing your MTU or
disabling Path MTU detection (which has the effect of dropping mtu to
576 anyway). If this helps, there is possibly a misconfigured
firewall, router or NAT between you and the ftp server.

Certain configurations (particularly firewalls dropping all ICMP
traffic, which is a Really Bad Idea) can result in strange
hard-to-trace problems with symptoms similar to those that you
describe when sending full-sized packets but not small packets, which
can explain why small files get through.