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Re: printer problem
From: m p <sumirati () yahoo de>
Date: Wed, 9 May 2001 11:59:20 +0200 (CEST)


traceroute works on a lower level of the TCP/IP
protocol hierachie than the ports are.

With traceroute itself you can not test it because of

But, you can try nmap from www.insecure.org. With this
tool you can check many setups of ports (open,
half-open, blocked with ip-filtering etc)

with the output you can than say something about the
status of the rules.

but - if there is a ip-filter, which is stateful and
configured as a "black-hole" there is no (easy) way to
find out about.

bye then


--- hermit1 <hermits () mac com> schrieb: > I have a very
odd problem.  There are people here
using a remote printer, 
and last week they lost access to the printer.  Of
course they blamed the 
firewall, but FW-1 logs show the connections going
out just fine.  Doing a 
telnet to the remote IP on port 515 times out. 
Traceroute, ping, telnet - 
all reach the destination.  We tried from home (two
different ISPs) and 
could not connect on port 515.

Sounds like port 151 was blocked at their end, but
users from other sites 
can reach that printer without trouble.  Their
network person can reach the 
printer from his home ISP, and print.

My guess is that someone somewhere put a block on
port 515.  Is there any 
way to find such a block?  Doing traceroute on port
515 would be good.....


This is an email.  Don't rely on anything seen here
as being accurate without testing it yourself.

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