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Re: Re: Inline IP_Forwarding and other simple questions?

From: "mdpeters" <michael.peters () lazarusalliance com>
Date: Thu, 30 Dec 2004 12:40:47 -0500
Snort-inline is not passing traffic through the bridge. I get drops to work comming into the box but nothing goes through for some reason. 

# /usr/local/sbin/iptables -L

Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain FORWARD (policy DROP)
target     prot opt source               destination
QUEUE      all  --  anywhere             anywhere
QUEUE tcp -- anywhere anywhere tcp flags:SYN,RST,ACK/SYN state NEW QUEUE tcp -- anywhere anywhere state RELATED,ESTABLISHED 
QUEUE      udp  --  anywhere             anywhere
QUEUE      icmp --  anywhere             anywhere

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
----- Original Message ----- From: "Will Metcalf" <william.metcalf () gmail com> 
To: "mdpeters" <michael.peters () lazarusalliance com>
Cc: "Michael D. Peters" <mdpeters () lazarusalliance com>; <snort-users () lists sourceforge net> 
Sent: Thursday, December 30, 2004 11:06 AM
Subject: Re: [Snort-users] Re: Inline IP_Forwarding and other simple questions? 



Just for grins try to leave the default in there and see if it still
dies.  if it does send me a core dump.

Regards,

Will


On Thu, 30 Dec 2004 09:50:02 -0500, mdpeters
<michael.peters () lazarusalliance com> wrote:
I am trying to set up Snort-inline. When I enable "config layer2resets:" it 
dies. Do I need to include the MAC of the bridge group, in my case,
00:04:23:AD:ED:BA to get it to reset connections with IPTABLES?

config layer2resets: 00:04:23:AD:ED:BA

eth0 00:04:23:AD:ED:BA
eth1 00:04:23:AD:ED:BB
br0  00:04:23:AD:ED:BA
Also, concerning rules for Snort-inline. Do I take to rules included in the 
tarball and modify the *.rules to something like this:

drop icmp $EXTERNAL_NET any -> $HOME_NET any (msg:"ICMP ISS Pinger";
itype:8; content:"ISSPNGRQ"; depth:32; reference:arachnids,158;
classtype:attempted-recon; sid:465; rev:3;)

or

sdrop icmp $EXTERNAL_NET any -> $HOME_NET any (msg:"ICMP ISS Pinger";
itype:8; content:"ISSPNGRQ"; depth:32; reference:arachnids,158;
classtype:attempted-recon; sid:465; rev:3;)

or

reject icmp $EXTERNAL_NET any -> $HOME_NET any (msg:"ICMP ISS Pinger";
itype:8; content:"ISSPNGRQ"; depth:32; reference:arachnids,158;
classtype:attempted-recon; sid:465; rev:3;)

or

drop icmp $HOME_NET any -> $EXTERNAL_NET any (msg:"ICMP ISS Pinger";
itype:8; content:"ISSPNGRQ"; depth:32; reference:arachnids,158;
classtype:attempted-recon; sid:465; rev:3;)

or something like these?

Thanks,

Michael

----- Original Message -----
From: "Will Metcalf" <william.metcalf () gmail com>
To: "Michael D. Peters" <mdpeters () lazarusalliance com>
Cc: "mdpeters" <michael.peters () lazarusalliance com>;
<snort-users () lists sourceforge net>
Sent: Tuesday, December 28, 2004 6:16 PM
Subject: [Snort-users] Re: Inline IP_Forwarding and other simple questions? 

>> What I am asking is since this uses IPTABLES, should I just set up
>> permanent
>> "firewall type" IPTABLE rules and then use the modified snort rules to
>> take
>> care of the resets, drops, etc?
>
> Yes
>
>
> On Tue, 28 Dec 2004 18:02:12 -0500, Michael D. Peters
> <mdpeters () lazarusalliance com> wrote:
>> What I am asking is since this uses IPTABLES, should I just set up
>> permanent
>> "firewall type" IPTABLE rules and then use the modified snort rules to
>> take
>> care of the resets, drops, etc?
>>
>>
>> Will Metcalf writes:
>>
>> >> If I have something like this:     <GATEWAY-ROUTER> connected to
>> >> <FIREWALL>
>> >> connected to <SNORT_INLINE> connected to <NETWORK HUB OR SWITCH>.
>> >> Would I
>> >> set the "var HOME_NET any" to "var HOME_NET nnn.nnn.nnn.nnn/xx?
>> >
>> > Yes
>> >
>> >> Do I need to make a startup script for IPTABLE rules or do I rely >> >> on >> >> drop.rules or both? I'm inclined to think that the firewall rules >> >> will 
>> >> be
>> >> essentially duplicated with IPTABLES and the drop.rules >> >> interactively 
>> >> supplement the IPTABLES.
>> >
>> > I'm not really sure what you are asking for here...... Usually it >> > is >> > a good idea to have a couple of iptables rules to check state for >> > tcp 
>> > state etc.  Just off the top of my head.....
>> >
>> > iptables -P FORWARD DROP
>> > iptables -A FORWARD -p tcp --syn -m state --state NEW -j QUEUE
>> > iptables -A FORWARD -p tcp -m state --state RELATED,ESTABLISHED -j
>> > QUEUE
>> > iptables -A FORWARD -p udp -j QUEUE
>> > iptables -A FORWARD -p icmp -j QUEUE
>> >
>> >>Would MySQL logging be done the same way for Snort-inline as it is >> >>with 
>> >>regular Snort?
>> >>
>> >>output database: alert, mysql, dbname=snort user=snortuser
>> >>host=localhost
>> >>password=snortuserpassword
>> >
>> > Yes
>> >
>> > Regards,
>> >
>> > Will
>> >
>> >
>> >
>> >
>> > On Tue, 28 Dec 2004 10:58:28 -0500, mdpeters
>> > <michael.peters () lazarusalliance com> wrote:
>> >> Concerning the snort-inline.conf file, are the "var" statements
>> >> relevant?
>> >> Should I specify the network and subnet that the snort-inline box >> >> runs 
>> >> on?
>> >>
>> >> If I have something like this:     <GATEWAY-ROUTER> connected to
>> >> <FIREWALL>
>> >> connected to <SNORT_INLINE> connected to <NETWORK HUB OR SWITCH>.
>> >> Would I
>> >> set the "var HOME_NET any" to "var HOME_NET nnn.nnn.nnn.nnn/xx?
>> >>
>> >> Do I need to make a startup script for IPTABLE rules or do I rely >> >> on >> >> drop.rules or both? I'm inclined to think that the firewall rules >> >> will 
>> >> be
>> >> essentially duplicated with IPTABLES and the drop.rules >> >> interactively 
>> >> supplement the IPTABLES.
>> >>
>> >> Thank you for the continued education and assistance.   :)
>> >>
>> >> ----- Original Message -----
>> >> From: "Will Metcalf" <william.metcalf () gmail com>
>> >> To: "mdpeters" <michael.peters () lazarusalliance com>
>> >> Sent: Monday, December 27, 2004 12:04 PM
>> >> Subject: Re: [Snort-users] Inline IP_Forwarding and other simple
>> >> questions?
>> >>
>> >> > because, you are not pulling traffic off of the bridge.  You are
>> >> > pulling traffic out of iptables, via the QUEUE target.  As far as
>> >> > the
>> >> > rules go, you need to convert alert to drop/sdrop/reject.
>> >> >
>> >> > Regards,
>> >> >
>> >> > Will
>> >> >
>> >> >
>> >> > On Mon, 27 Dec 2004 11:36:10 -0500, mdpeters
>> >> > <michael.peters () lazarusalliance com> wrote:
>> >> >> One instance for both interfaces or just one like you wrote? How
>> >> >> does it
>> >> >> know what interface the bridge is on?
>> >> >>
>> >> >>
>> >> >> ----- Original Message -----
>> >> >> From: "Will Metcalf" <william.metcalf () gmail com>
>> >> >> To: "mdpeters" <michael.peters () lazarusalliance com>
>> >> >> Sent: Monday, December 27, 2004 11:00 AM
>> >> >> Subject: Re: [Snort-users] Inline IP_Forwarding and other simple
>> >> >> questions?
>> >> >>
>> >> >> > look at inline readme file under doc in your source.
>> >> >> >
>> >> >> > you were close....
>> >> >> >
>> >> >> > /opt/snort/bin/snort-inline -Q -l /var/log/snort/ -D -c
>> >> >> > /opt/snort/etc/snort_inline.conf
>> >> >> >
>> >> >> > something like that...
>> >> >> >
>> >> >> > Regards,
>> >> >> >
>> >> >> > Will
>> >> >> >
>> >> >> >
>> >> >> > On Mon, 27 Dec 2004 09:46:33 -0500, mdpeters
>> >> >> > <michael.peters () lazarusalliance com> wrote:
>> >> >> >> Right now I have this running:
>> >> >> >>
>> >> >> >> /opt/snort/bin/snort-inline -Q -c >> >> >> >> /opt/snort/etc/inline1.conf -i 
>> >> >> >> eth1 -l
>> >> >> >> /var/log/snort-inline1 -D
>> >> >> >> /opt/snort/bin/snort-inline -Q -c >> >> >> >> /opt/snort/etc/inline2.conf -i 
>> >> >> >> eth2 -l
>> >> >> >> /var/log/snort-inline2 -D
>> >> >> >>
>> >> >> >> I apparently do not understand how inline works.
>> >> >> >>
>> >> >> >> What would the snort-inline command be to work on a >> >> >> >> transparent 
>> >> >> >> bridge
>> >> >> >> snort-inline with iptables?
>> >> >> >>
>> >> >> >> Where can I read up?
>> >> >> >>
>> >> >> >> I appreciate your help!
>> >> >> >>
>> >> >> >> ----- Original Message -----
>> >> >> >> From: "Will Metcalf" <william.metcalf () gmail com>
>> >> >> >> To: "mdpeters" <michael.peters () lazarusalliance com>
>> >> >> >> Sent: Monday, December 27, 2004 8:14 AM
>> >> >> >> Subject: Re: [Snort-users] Inline IP_Forwarding and other >> >> >> >> simple 
>> >> >> >> questions?
>> >> >> >>
>> >> >> >> > neither you would use the -Q switch to tell snort to read >> >> >> >> > from 
>> >> >> >> > ip_queue.  Then you have to send traffic to snort with
>> >> >> >> > iptables with
>> >> >> >> > a
>> >> >> >> > rule like this.
>> >> >> >> >
>> >> >> >> > iptables -A FORWARD -j QUEUE
>> >> >> >> >
>> >> >> >> >
>> >> >> >> > On Mon, 27 Dec 2004 00:06:30 -0500, mdpeters
>> >> >> >> > <michael.peters () lazarusalliance com> wrote:
>> >> >> >> >> Would I need to use the bridge "br0" group interface or >> >> >> >> >> the 
>> >> >> >> >> individual
>> >> >> >> >> interfaces "eth0' and "eth1" that make up the group for >> >> >> >> >> the 
>> >> >> >> >> Snort-inline
>> >> >> >> >> start command?
>> >> >> >> >>
>> >> >> >> >> Thanks,
>> >> >> >> >> Michael
>> >> >> >> >>
>> >> >> >> >> ----- Original Message -----
>> >> >> >> >> From: "Will Metcalf" <william.metcalf () gmail com>
>> >> >> >> >> To: "Matt Kettler" <mkettler () evi-inc com>
>> >> >> >> >> Cc: "mdpeters" <michael.peters () lazarusalliance com>;
>> >> >> >> >> <snort-users () lists sourceforge net>
>> >> >> >> >> Sent: Thursday, December 23, 2004 4:43 PM
>> >> >> >> >> Subject: Re: [Snort-users] Inline IP_Forwarding and other
>> >> >> >> >> simple
>> >> >> >> >> questions?
>> >> >> >> >>
>> >> >> >> >> > Well said, except that drop does not reset the >> >> >> >> >> > connection. 
>> >> >> >> >> > Using
>> >> >> >> >> > reject will drop and reset the connection.
>> >> >> >> >> >
>> >> >> >> >> > Regards,
>> >> >> >> >> >
>> >> >> >> >> > Will
>> >> >> >> >> >
>> >> >> >> >> > On Thu, 23 Dec 2004 15:21:37 -0500, Matt Kettler
>> >> >> >> >> > <mkettler () evi-inc com>
>> >> >> >> >> > wrote:
>> >> >> >> >> >> At 02:04 PM 12/23/2004, mdpeters wrote:
>> >> >> >> >> >> >Do I need to enable ip_forwarding on for the >> >> >> >> >> >> >transparent 
>> >> >> >> >> >> >bridge
>> >> >> >> >> >> >to
>> >> >> >> >> >> >work?
>> >> >> >> >> >>
>> >> >> >> >> >> As I understand it, you explicitly MUST NOT enable
>> >> >> >> >> >> ip_forwarding,
>> >> >> >> >> >> otherwise
>> >> >> >> >> >> your snort-inline is a "pass all".
>> >> >> >> >> >>
>> >> >> >> >> >> >
>> >> >> >> >> >> >Do I need to install ebtables for inline to disrupt
>> >> >> >> >> >> >traffic or
>> >> >> >> >> >> >is
>> >> >> >> >> >> >iptables, libnet, and libpcap all that I might need?
>> >> >> >> >> >>
>> >> >> >> >> >> AFAIK you don't need ebtables.  You do need libipq for
>> >> >> >> >> >> inline
>> >> >> >> >> >> and
>> >> >> >> >> >> libnet.
>> >> >> >> >> >> This is how snort-inline attaches to iptables by using
>> >> >> >> >> >> libipq
>> >> >> >> >> >> instead
>> >> >> >> >> >> of
>> >> >> >> >> >> using libpcap.
>> >> >> >> >> >>
>> >> >> >> >> >>
>> >> >> >> >> >> > It is my impression that iptables just firewalls >> >> >> >> >> >> > with 
>> >> >> >> >> >> > static
>> >> >> >> >> >> > rules.
>> >> >> >> >> >>
>> >> >> >> >> >> On it's own, yes, but IPTables is VERY extensible via
>> >> >> >> >> >> libipq..
>> >> >> >> >> >>
>> >> >> >> >> >> That's where snort-inline comes in. Snort-inline >> >> >> >> >> >> interacts 
>> >> >> >> >> >> with
>> >> >> >> >> >> iptables.
>> >> >> >> >> >> It doesn't do things like create iptables rules to >> >> >> >> >> >> block 
>> >> >> >> >> >> packets,
>> >> >> >> >> >> it
>> >> >> >> >> >> the
>> >> >> >> >> >> whole system becomes an iptables rule, it just happens >> >> >> >> >> >> to 
>> >> >> >> >> >> be a
>> >> >> >> >> >> rule
>> >> >> >> >> >> that
>> >> >> >> >> >> runs snort instead of some simple expression.
>> >> >> >> >> >>
>> >> >> >> >> >>
>> >> >> >> >> >> >
>> >> >> >> >> >> >Do the snort rules running on the transparent inline
>> >> >> >> >> >> >snort box
>> >> >> >> >> >> >reset
>> >> >> >> >> >> >the
>> >> >> >> >> >> >traffic that passes through using inline?
>> >> >> >> >> >>
>> >> >> >> >> >> Depends on if you use DROP or SDROP :).. However, >> >> >> >> >> >> inline 
>> >> >> >> >> >> doesn't
>> >> >> >> >> >> JUST
>> >> >> >> >> >> reset
>> >> >> >> >> >> the traffic.. it also prevents the packet from being
>> >> >> >> >> >> forwarded
>> >> >> >> >> >> at
>> >> >> >> >> >> all.
>> >> >> >> >> >> DROP
>> >> >> >> >> >> will also reset, SDROP won't.
>> >> >> >> >> >>
>> >> >> >> >> >> Snort 2.3's inline capacity is a direct port of
>> >> >> >> >> >> snort-inline.
>> >> >> >> >> >> You
>> >> >> >> >> >> might
>> >> >> >> >> >> want to check their FAQ for other info:
>> >> >> >> >> >>
>> >> >> >> >> >> http://snort-inline.sourceforge.net/FAQ.html
>> >> >> >> >> >>
>> >> >> >> >> >> -------------------------------------------------------
>> >> >> >> >> >> 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://productguide.itmanagersjournal.com/
>> >> >> >> >> >> _______________________________________________
>> >> >> >> >> >> 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
>> >> >> >> >> >>
>> >> >> >> >> >
>> >> >> >> >> >
>> >> >> >> >> > -------------------------------------------------------
>> >> >> >> >> > 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://productguide.itmanagersjournal.com/
>> >> >> >> >> > _______________________________________________
>> >> >> >> >> > 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
>> >> >> >> >> >
>> >> >> >> >>
>> >> >> >> >>
>> >> >> >> >
>> >> >> >>
>> >> >> >>
>> >> >> >
>> >> >>
>> >> >>
>> >> >
>> >>
>> >>
>>
>>
>> Best regards,
>>
>> Michael D. Peters
>> Director of Security Services
>> CISSP
>> Lazarus Alliance Inc.
>> M: 502-767-3448
>> O: 502-231-8017 x8
>> H: 502-231-6923
>> F: 502-231-5347
>>
>> michael.peters () lazarusalliance com
>> www.lazarusalliance.com
>>
>> Verify here: http://wwwkeys.us.pgp.net
>>
>>
>
>
> -------------------------------------------------------
> 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://productguide.itmanagersjournal.com/
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