Snort mailing list archives

Snort inline setup issues


From: The Adept <adept () stephans org>
Date: Thu, 28 Sep 2006 10:27:34 -0500

I am setting up a snort IPS on a Gentoo 2.6 box and I've run into a wall 
getting Snort to pass the packets out of the iptables queue.

For testing I have the snort box which sits on a 10.x.x.x address, it 
has a dual ethernet card to use for the inline bridge.  I have two 
different boxes connected to the dual ethernet card, one with 
192.168.100.1 as its address and one with 192.168.100.2.  The bridge 
(br0) works perfectly with -P FORWARD ACCEPT set and no snort.  When I 
change policy to DROP packets are correctly dropped (all protocols).  
When I enable snort, it sees the packets and ICMP works (pings) but tcp 
does not.  (log attached below)

I'm not sure what I'm doing wrong.  Everything appears to be set up 
correctly but no tcp sessions are being properly set up.  Any suggestions?

Thanks in advance for any advice.

Cheers,

 Dan

09/28-09:52:23.122172 192.168.100.1 -> 192.168.100.2
ICMP TTL:64 TOS:0x0 ID:0 IpLen:20 DgmLen:84 DF
Type:8  Code:0  ID:41257   Seq:256  ECHO
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+

09/28-09:52:23.122394 192.168.100.2 -> 192.168.100.1
ICMP TTL:64 TOS:0x0 ID:4712 IpLen:20 DgmLen:84
Type:0  Code:0  ID:41257  Seq:256  ECHO REPLY
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+

09/28-09:52:33.806050 192.168.100.1:33430 -> 192.168.100.2:22
TCP TTL:64 TOS:0x0 ID:58483 IpLen:20 DgmLen:60 DF
******S* Seq: 0xC52F7745  Ack: 0x0  Win: 0x16D0  TcpLen: 40
TCP Options (5) => MSS: 1460 SackOK TS: 250778422 0 NOP WS: 0
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+

09/28-09:52:36.801000 192.168.100.1:33430 -> 192.168.100.2:22
TCP TTL:64 TOS:0x0 ID:58484 IpLen:20 DgmLen:60 DF
******S* Seq: 0xC52F7745  Ack: 0x0  Win: 0x16D0  TcpLen: 40
TCP Options (5) => MSS: 1460 SackOK TS: 250778722 0 NOP WS: 0
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+

09/28-09:52:42.800391 192.168.100.1:33430 -> 192.168.100.2:22
TCP TTL:64 TOS:0x0 ID:58485 IpLen:20 DgmLen:60 DF
******S* Seq: 0xC52F7745  Ack: 0x0  Win: 0x16D0  TcpLen: 40
TCP Options (5) => MSS: 1460 SackOK TS: 250779322 0 NOP WS: 0
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+


-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys -- and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
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: