[Snort-users] -o and pass/alert/log usage

Joe Fico Fico at ...2391...
Wed Jun 27 19:05:13 EDT 2001

Well I changed my rules to look like this.

#pass icmp any <- any any (msg:"PASSING ICMP from N.A. NOC
alert icmp any <- any any (msg:" ALERTING ICMP FROM N.A. NOC

and I got this message.

Jun 27 15:54:52 localhost snort[5629]: ALERTING ICMP FROM N.A. NOC Server: ->

so thats cool now I can uncomment out the pass rule and I get...


Why don't I get a message for the pass rule?

> -----Original Message-----
> From: joey at ...47... [mailto:joey at ...47...]
> Sent: Wednesday, June 27, 2001 3:39 PM
> To: Sheahan, Paul (PCLN-NW); 'Joe Fico'
> Cc: Snort-users
> Subject: Re: [Snort-users] -o and pass/alert/log usage
> Paul: That is correct.  Pass rules take precedence when -o is used,
> regardless of where they are located with respect to alert rules.
> Joe:  Looking at your problem, I'm wondering if your ROUTER ICMP alert
> rules contain addresses that are outside of your HOME_NET.  This would
> explain why they are not being passed on.  First, make them valid
> addresses by adding the /32 netmask.  Next, confirm that they do exist
> in your HOME_NET.  If that doesn't help, try changing $HOME_NET in your
> pass rules to "any".  Next, I would try removing the $HOME_NET variables
> from the msg field, take out the "->" in the msg field while you are at
> it.  We're just making sure Snort is parsing the rule incorrectly.
> Post back with your findings.
> Hope this helps,
> -Joe M.

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