continued IPFW issues... (actually a lack of ability on my part)

[Erik Trulsson]

On Sat, Feb 14, 2004 at 07:42:28PM -0600, Eric F Crist wrote:
> On Saturday 14 February 2004 06:59 pm, Jez Hancock wrote:
> > On Sat, Feb 14, 2004 at 05:59:14PM -0600, Eric F Crist wrote:
> > > On Sat, Feb 14, 2004 at 03:27:35PM -0600, Eric F Crist wrote:
> > > > I'm still having some sort of issues with ipfw rules on my server.
> > > > I've got a
> > > > cgi based irc client installed, and I can't connect.  Also, it seems
> > >
> > > as if my
> > >
> > > > DNS server isn't able to send queries out.  An ipfw show displays the
> > > > following for me:
> > > >
> > > > 00050 54632 4640473 allow ip from me to any
> > > > 00100     0       0 allow ip from any to any via lo0
> > > > 00200     0       0 deny ip from any to 127.0.0.0/8
> > > > 00300     0       0 deny ip from 127.0.0.0/8 to any
> > > > 00400  4027  351563 allow ip from 63.228.14.240/29 to me
> > > > 00500     2      80 allow ip from any to me dst-port 22
> > > > 00600     2      80 allow ip from any to me dst-port 21
> > > > 00700   388   25405 allow ip from any to me dst-port 25
> > > > 00800    58    4944 allow ip from any to me dst-port 80
> > > > 00900     2      80 allow ip from any to me dst-port 443
> > > > 01000     2      80 allow ip from any to me dst-port 110
> > > > 01100    54    4247 allow ip from any to me dst-port 53
> > > > 01200     2      80 allow ip from any to me dst-port 6667
> > > > 01300     2      80 allow ip from any to me dst-port 6668
> > > > 01400     4     160 deny ip from not 63.228.14.240/29 to me dst-port
> > >
> > > 8080
> > >
> > > > 65535 46432 7224466 deny ip from any to any
> > > >
> > > > Where is all that denied traffic coming from on the final rule?
> > >
> > > You are only allowing traffic in and not out - as Matthew Seaman
> > > mentioned in the last post in your previous thread, you should use
> > > 'keep-state' to keep track of the connections made to you.  See the
> > > examples he provided in that thread.
> > >
> > > >From the manpage for ipfw:
> > >
> > >      check-state
> > > 	     Checks the packet against the dynamic ruleset.  If a match
> > > is
> > > 	     found, execute the action associated with the rule which
> > > gener-
> > > 	     ated this dynamic rule, otherwise move to the next rule.
> > > 	     Check-state rules do not have a body.  If no check-state
> > > rule is
> > > 	     found, the dynamic ruleset is checked at the first
> > > keep-state or
> > > 	     limit rule.
> > >
> > > ...
> > >
> > >      keep-state
> > > 	     Upon a match, the firewall will create a dynamic rule,
> > > whose
> > > 	     default behaviour is to match bidirectional traffic between
> > > 	     source and destination IP/port using the same protocol.
> > > The rule
> > > 	     has a limited lifetime (controlled by a set of sysctl(8)
> > > vari-
> > > 	     ables), and the lifetime is refreshed every time a matching
> > > 	     packet is found.
> > >
> > > When a connection is made to port 80 from an external host, with the
> > > 'keep-state' flag set on your rule for port 80 data transfer will be
> > > allowed in both directions to/from the external host to/from you on port
> > > 80 for a limited period.  The check-state rule effectively 'shortcuts'
> > > the rest of the rules in the ruleset if a match is made for the external
> > > host for the given action (inbound connections to port 80 in this case).
> > >
> > > You'd need to do the same for each of the other ports you want to allow
> > > free connections to/from.
> > >
> > > Wouldn't my first rule:
> > >
> > > ipfw allow ip from me to any
> > >
> > > have fixed this problem?
> >
> > Sorry I missed that rule :(  How about adding a log keyword to that last
> > deny rule temporarily just to see what exactly is being denied?
> 
> Maybe I'm missing something somewhere, but I can't find anything about log in 
> the man page.  I tried:

The you need to read the man page more carefully, because it is there.
Look for the the section titled "RULE FORMAT"


> ipfw add 65534 add deny ip from any to any log and got this error:

Try

ipfw add 65534 deny log ip from any to any

instead, and it ought to work better.

> 
> ipfw: unrecognised option [-1] log
> 
> Thanks.
> 
> -- 
> Eric F Crist
> AdTech Integrated Systems, Inc
> (612) 998-3588



-- 
<Insert your favourite quote here.>
Erik Trulsson
ertr1013 at student.uu.se