Snort mailing list archives

Re: Everything being triggered as 1:486:4 ICMP unreachable


From: David Ryan <David.Ryan () Quintiles com>
Date: Tue, 5 Jun 2007 11:17:14 +0100

Todd,

Thanks for the reply.  It was indeed a firewall issue - the device I was scanning was sending ICMP Host 
Administratively Unreachable packets when I tried certain scans, so I was seeing those packets.  As per the detail 
below I wasn't seeing the original traffic because of a problem with the _NET definitions.

Thanks,

David
-----Original Message-----
From: Todd Wease [mailto:twease () sourcefire com]
Sent: 30 May 2007 13:15
To: David Ryan
Cc: snort-users () lists sourceforge net
Subject: Re: [Snort-users] Everything being triggered as 1:486:4 ICMP unreachable

David Ryan wrote:

All,



To partly reply to my own question - one of my flaws was keeping
$HOME_NET as 10.0.0.0/8 - this prevented most of my test traffic from
triggering since my tests were coming from $HOME_NET and not
$EXTERNAL_NET.  This was significant where the rule I was testing was
of the form $EXTERNAL_NET -> $HOME_NET

[SNIP]

David


Sounds like it might be a firewall issue.  This response is usually sent
by a firewall to say that it's filter won't allow communication with
that host/port.  It may be allowing ssh to that host (port 22) and may
be allowing pings, but not allowing the host/port combo used in your test.

Todd

**********************  IMPORTANT--PLEASE READ  ************************
This electronic message, including its attachments, is COMPANY CONFIDENTIAL
and may contain PROPRIETARY or LEGALLY PRIVILEGED information.  If you are 
not the intended recipient, you are hereby notified that any use, disclosure,
copying, or distribution of this message or any of the information included
in it is unauthorized and strictly prohibited.  If you have received this
message in error, please immediately notify the sender by reply e-mail and
permanently delete this message and its attachments, along with any copies
thereof. If this electronic message contains a zipped attachment and you do
not have a decompression tool, you may download unZIP (free of cost) from:
http://www.mk-net-work.com/us/uz/unzip.htm. Alternatively, you may request
that the attachment be resent in an uncompressed format.        Thank you. 
************************************************************************


-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
Snort-users mailing list
Snort-users () lists sourceforge net
Go to this URL to change user options or unsubscribe:
https://lists.sourceforge.net/lists/listinfo/snort-users
Snort-users list archive:
http://www.geocrawler.com/redir-sf.php3?list=snort-users


Current thread: