[Snort-users] A question now that I have nfq working

James Lay jlay at ...13475...
Tue Apr 8 18:49:00 EDT 2014


So...it appears that that snort using nfq pass the packet along, if 
it's not dropped by the IDS, regardless of other rules.  Example:

Let's say I have a rule:

drop tcp any any -> any 80 (msg:"Test 80"; sid:10000053;)

I send all my traffic to my INPUT with:

sudo /sbin/iptables -I INPUT -p tcp --dport 80 -j NFQUEUE --queue-num 1

But I also have a block rule say to 445:
pkts bytes target     prot opt in     out     source               
destination
   699 57925 NFQUEUE    all  --  *      *       0.0.0.0/0            
0.0.0.0/0            NFQUEUE num 1
     0     0 DROP       tcp  --  *      *       0.0.0.0/0            
0.0.0.0/0            tcp dpt:445

So even though I have this drop rule above to 445, I see:

telnet 192.168.1.6 445
Trying 192.168.1.6...
Connected to 192.168.1.6.
Escape character is '^]'.

I've found that after passing through the nfqueue as not dropping, it 
appears the packet is sent along, but not to the next iptables rule.  
Can someone confirm this behavior?  Thank you.

James




More information about the Snort-users mailing list