RE: How do I find out what hop is not forwarding traffic on a specific port?

["Billy Macdonald" <bmacdonald () crosscountry-auto com>]

From Linux you can do this.

traceroute -T -p 80 www.google.com 
traceroute -U -p 53 a.root-servers.net.

Note that the DNS one above seems to fail when it actually gets to the DNS server as it's not a valid packet and 
therefore discarded by the server.

Good Luck

-----Original Message-----
From: listbounce () securityfocus com [mailto:listbounce () securityfocus com] On Behalf Of Alex Fiuvertiz
Sent: Wednesday, November 18, 2009 3:11 PM
To: Phunkodelic
Cc: security-basics () securityfocus com
Subject: Re: How do I find out what hop is not forwarding traffic on a specific port?

Perhaps firewalk will solve that question? I'm not sure I completely
understood the problem, but if you're having a firewall/router in
front of a network and wants to map the firewall's rulebase than
perhaps firewalk could help.
But you will have to know a host on the inside network of the filtering devices.
The method will only work at level 3 firewalls/filtering devices.
You let firewalk calculate the TTL so that TTL is 1 when you get to
the firewall/router/filtering device. If the firewall is letting the
traffic through, the TTL will reach 0 and a ICMP message is returned.
If the fw is not letting the traffic through, the packet is simply
dropped.

/ Alex

2009/11/5 Phunkodelic <phunkodelic () gmail com>:
> Looking for a way to find out who or what device is blocking traffic
> on a specific port.  Sort of like a trace route tool where you could
> designate the port to test with (UDP/TCP).  I realize that UDP may be
> hard to do since it is a connectionsless protocol.
>
> Anybody?  Thanks in advanced.
>
> ------------------------------------------------------------------------
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> In this guide we examine the importance of Apache-SSL and who needs an SSL certificate.  We look at how SSL works, 
> how it benefits your company and how your customers can tell if a site is secure. You will find out how to test, 
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> http://www.dinclinx.com/Redirect.aspx?36;4175;25;1371;0;5;946;e13b6be442f727d1
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------------------------------------------------------------------------
Securing Apache Web Server with thawte Digital Certificate
In this guide we examine the importance of Apache-SSL and who needs an SSL certificate.  We look at how SSL works, how 
it benefits your company and how your customers can tell if a site is secure. You will find out how to test, purchase, 
install and use a thawte Digital Certificate on your Apache web server. Throughout, best practices for set-up are 
highlighted to help you ensure efficient ongoing management of your encryption keys and digital certificates.

http://www.dinclinx.com/Redirect.aspx?36;4175;25;1371;0;5;946;e13b6be442f727d1
------------------------------------------------------------------------


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------------------------------------------------------------------------
Securing Apache Web Server with thawte Digital Certificate
In this guide we examine the importance of Apache-SSL and who needs an SSL certificate.  We look at how SSL works, how 
it benefits your company and how your customers can tell if a site is secure. You will find out how to test, purchase, 
install and use a thawte Digital Certificate on your Apache web server. Throughout, best practices for set-up are 
highlighted to help you ensure efficient ongoing management of your encryption keys and digital certificates.

http://www.dinclinx.com/Redirect.aspx?36;4175;25;1371;0;5;946;e13b6be442f727d1
------------------------------------------------------------------------