Sorry if this isn't the right place for this but I don't know where
else
to turn.
A client of mine has recently started having connection problems to my
ftp server hosted under Debian. He says he simply cannot reach us. I
can
ftp just fine to his server. They think we have changed something on
our
end that would cause this problem. I've checked our access-list on our
Cisco but there's nothing there blocking ftp connections.
I'm planning on a little field trip to their office over the next week
to
try to troubleshoot the problem. What methods can I use to find out
what is stopping the connection. The only methods I know of are ping
and
traceroute but that's not going to tell me what's causing the problem.
My
server is connected via Sprint. Their server is connected via Verizon.
Personally I think it's something on Verizon blocking ftp from their
end
but I need to be able to prove it to them so they will go after their
ip
provider with the evidence.