Micky, The router isn't listening on that port. The traceroute program
on a Cisco sends packets to that port and when it gets a "destination
port unreachable" message(because the router isn't listening on that
port), it knows that the trace is complete.
Marcus.
-----Original Message-----
From: micky [mailto:micky@apol.com.tw]
Sent: 29 November 2001 10:05
To: swm@emanon.com
Cc: cisco-nsp@puck.nether.net
Subject: Re: [nsp] Cisco ios traceroute VS. windows tracert ?
Hi Scott
Thanks for providing information
You said Cisco listening-UDP port number is 33434 for
tracerouting ,but I can't scan the port with scan tools
Is it hidden port ?
Micky
----- Original Message -----
From: Scott Morris <mailto:swm@emanon.com>
To: 'micky' <mailto:micky@apol.com.tw> ;
cisco-nsp@puck.nether.net
Sent: Wednesday, November 28, 2001 8:18 PM
Subject: RE: [nsp] Cisco ios traceroute VS. windows
tracert ?
You have the right idea, just a little backwards!
Cisco IOS traceroute, like unix traceroute is a
UDP-based system. It sends out packets destined to a high UDP port
(33434 by default).
Microsoft tracert on the other hand functions just like
a ping. It sends out ICMP echo packets incrementing the TTL in the same
fashion.
So depending on access-lists on routers between you and
your destination, you may get very different results (and perhaps
different paths) depending on which box you run the trace from.
Hope that helps!
Scott
-----Original Message-----
From: micky [mailto:micky@apol.com.tw]
Sent: Wednesday, November 28, 2001 5:10 AM
To: cisco-nsp@puck.nether.net
Subject: [nsp] Cisco ios traceroute VS. windows
tracert ?
Hi Mr.techs
I have a little confusing about traceroute
function between cisco ios and windows utility
Sometimes I used "tracert -d" x.x.x.x
command under windows,it can go through all nodes and display ip address
of all
But using traceroute under IOS,it can goes
through all and display * * *
Somebody told me tracert is
UDP-designed,traceroute is ICMP-designed
I don't know if it's real or not ?
Thanks
Micky
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