Re: suppresing events from private lan

[Matt Kettler <mkettler () evi-inc com>]

At 05:56 PM 2/17/2005, hans wrote:
> thanks for answering again.
> i did change the config due to your recommendations.
> it seems, it is working as expected.
>
> but this means, if snort could see an attack from
> internet to my private lan ( it's really at home )
> it would also log this to file, or whatever defined.

Yes. In general, snort rules look for attacks from EXTERNAL_NET to HOME_NET.


However, one thing to be aware of is to keep in mind what it's possible for 
snort to see.

Your 172.20.1.0/24 is a reserved non-routable IP range, implying you've got 
a NAT somewhere.... If snort is sniffing your outside interface on a NAT 
firewall, it's never going to see packets addressed there, and you should 
leave that part out.  If snort is also sniffing a post-nat interface, then 
you want to include those IPs.

(Remember, outside of your private network, those addresses are not 
routeable, thus your ISP will never forward packets addressed to 
172.20.1.0/24 to your network. They don't even know you are using that 
address space, nor do they care. They only care about the address you NAT 
against.)




-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
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