Snort mailing list archives

RE: No Alerts Being Generated


From: "Kaplan, Andrew H." <AHKAPLAN () PARTNERS ORG>
Date: Wed, 6 Oct 2004 12:49:41 -0400

I ran Snort in packet sniffer mode and indeed it is seeing traffic. To answer
your other question 
about the interface, I am specifying the interface in the command line.

-----Original Message-----
From: sekure [mailto:sekure () gmail com]
Sent: Wednesday, October 06, 2004 12:34 PM
To: Kaplan, Andrew H.
Cc: Martin Roesch; Snort User Group (E-mail)
Subject: Re: [Snort-users] No Alerts Being Generated


Andrew,

Let's go back to the basics...  Try running snort in packet sniffer
mode, dumping the traffic to console: "snort -devi <int>".  Obviously
substitute your interface name for <int>.  You should quickly see if
Snort is seeing ANY traffic at all.... Speaking of which, are you
specifying an interface on the command line when you try to run snort
in nids mode???  That could be your problem.


On Wed, 6 Oct 2004 11:39:04 -0400, Kaplan, Andrew H.
<ahkaplan () partners org> wrote:
Hi there --

I created the test rule you had specified and then restarted Snort. I then
ran a series of scans, including the fingerprint scan, using nmapFE on a
remote
machine.
None of the scans resulted in alerts being shown. There is no question that
something
is configured wrong, unfortunately I don't know what it is. I am including the
snort.conf
file with this e-mail. Someone mentioned channging the EXTERNAL_NET option
from
any to !HOME_NET.
I tried that approach without any difference and thereafter changed it back.
Thanks for your help.




-----Original Message-----
From: Martin Roesch [mailto:roesch () sourcefire com]
Sent: Wednesday, October 06, 2004 10:01 AM
To: Kaplan, Andrew H.
Cc: Snort User Group (E-mail)
Subject: Re: [Snort-users] No Alerts Being Generated

Have you tried making a test rule?  How about:

alert tcp any any -> any any (msg: "TCP packet";)

put that in a file called test.rule then run

snort -c test.rule -A console -N

for a couple minutes and surf around the web, you should have alerts.
If you don't have alerts then something is probably configured wrong,
if you do have alerts then your test case (running Newt in front of
Snort) probably isn't generating anything that Snort is looking for.
Try running some real attacks or an nmap fingerprint scan.

     -Marty

On Oct 6, 2004, at 8:00 AM, Kaplan, Andrew H. wrote:

Hi there -- (sorry if this a repeat of a message sent out)

I made the change within the snort.conf file you had suggested. I also
ran the
snort -T command
and it ran through the configuration without reporting back any
errors. Finally,
I installed NeWT,
the Windows version of Nessus, on another machine and ran several
different
tests on the snort box.
The tests I ran were portscans and the "SANS Top 20" list. After the
scans were
finished, I checked
the alert file as well as the ACID GUI. Neither one mentioned any alert
conditions taking place.

As a further test, I changed the !HOME_NET setting back to any to see
if that
made any difference.
It did not. What should I look for next?


-----Original Message-----
From: Nigel Houghton [mailto:nigel () sourcefire com]
Sent: Wednesday, September 29, 2004 4:57 PM
To: snort-users () lists sourceforge net
Cc: Kaplan, Andrew H.
Subject: Re: [Snort-users] No Alerts Being Generated


Well the first thing I see in your file is the EXTERNAL_NET variable
is set
to any. You might want to set that to !$HOME_NET for a start.

Second, you can run snort -T -c /etc/snort/snort.conf to test your
snort
configuration.

Next thing is to make sure your snort box is listening on a span port
of a
switch or a tap or a hub (probably not using one in your case I think)
and
that the span port/tap is configured correctly.

Then, if possible, you could try generating some traffic that Snort
should
alert on, like maybe a web request for ftp.pl which should set off sid
1107. You could run some nessus tests or just do it manually with a
straightforward http://www.yourwebhost.org/ftp.pl or pick some other
simple
rule to test.

On  0, snort-users-request () lists sourceforge net allegedly wrote:
   3. No Alerts Being Generated (Kaplan, Andrew H.)

--__--__--

Message: 3
From: "Kaplan, Andrew H." <AHKAPLAN () PARTNERS ORG>
To: "Snort User Group (E-mail)" <snort-users () lists sourceforge net>
Date: Wed, 29 Sep 2004 15:35:26 -0400
Subject: [Snort-users] No Alerts Being Generated

This message is in MIME format. Since your mail reader does not
understand
this format, some or all of this message may not be legible.

------_=_NextPart_000_01C4A65B.7895D89C
Content-Type: text/plain;
     charset="iso-8859-1"

I completed installing snort 2.2.0 (build 30) and have begun running
it. The
ACID GUI and /var/log/snort/alert files have not shown any alerts
even though the program has been running for over an hour. To verify
there
were
no syntax errors in the snort.conf file, I ran the following:

snort -c /etc/snort/snort.conf

There were no errors and warnings, and the program appears to be
running
properly. Where in snort.conf and elsewhere, should I check for
configuration mistakes? I have included the snort.conf file here.
Thanks.

 <<snort.conf.29sept04.txt>>



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--
Martin Roesch - Founder/CTO, Sourcefire Inc. - +1-410-290-1616
Sourcefire - Discover.  Determine.  Defend.
roesch () sourcefire com - http://www.sourcefire.com
Snort: Open Source Network IDS - http://www.snort.org





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