Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 31 Jan 2000 21:54:56 +0200
From:      Ruslan Ermilov <ru@ucb.crimea.ua>
To:        John <papalia@udel.edu>
Cc:        zimon@iki.fi, freebsd-questions@FreeBSD.ORG
Subject:   Re: NATD/Divert broken ?
Message-ID:  <20000131215456.B97751@relay.ucb.crimea.ua>
In-Reply-To: <4.1.20000131123443.00975da0@mail.udel.edu>; from John on Mon, Jan 31, 2000 at 02:23:34PM -0500
References:  <4.1.20000131120328.009749c0@mail.udel.edu> <4.1.20000131120328.009749c0@mail.udel.edu> <20000131193116.A72155@relay.ucb.crimea.ua> <4.1.20000131123443.00975da0@mail.udel.edu>

next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Jan 31, 2000 at 02:23:34PM -0500, John wrote:
> >> Hey all,
> >> 
> >> I'm having a small problem with my NATD and my firewall.  Per the
> >> instructions in "The Complete FreeBSD", I added the firewall rule:
> >> 
> >> divert natd ip from any to any via fxp1
> >> 
> >> The problem is that this rule is causing partial problems on my loopback
> >> device (lo0).
> >> 
> >> What happens is that with the rule in place, for some connections within
> >> the box (which definitely go thru lo0), the connections fail.  If I remove
> >> that rule, then the connections within the box can be made, but then I lose
> >> all ability to host my internal 192.168. net.
> >> 
> >> I have done tcpdumps of both the successful and unsuccessful connections
> >> and have pasted them below.  If the actual tcpdump files would be useful, I
> >> can attach those to a subsequent email. 
> >> 
> >> Also, I'm currently running 3.3 and am suffering from NO other apparent
> >> problems with lo0 that I can tell.
> >> 
> >> tcpdumps are below.
> >> 
> >> Thanks in advance,
> >> John
> >> 
> >
> >> ******
> >> Failed connection, with divert rule in place:
> >> ******
> >> 
> >> 12:01:10.744362 merlin.wondermutt.net.3482 > merlin.wondermutt.net.39536: S
> >> 1027967984:1027967984(0) win 16384 <mss 16344,nop,wscale 0,nop,no
> >> 
> >[...]
> >Can you show me the above in numerical form (with -n), with the output of
> >the following commands:
> 
> Sure can :)
> 
[...]
> >* ipfw show
> merlin# ipfw show
> 00075   227   21816 divert 8668 ip from any to any via fxp1
> 00150 18596 3000493 allow ip from any to any via fxp0
> 00200     0       0 deny ip from any to 127.0.0.0/8 recv fxp1
> 00300    22    1233 allow ip from 192.168.0.0/16 to any out xmit fxp1
> 00400  1205 1317527 allow ip from any to 192.168.0.0/16 in recv fxp1
> 65000   250   22128 allow ip from any to 128.175.75.157 in recv fxp1
> 65100  1380   78451 allow ip from 128.175.75.157 to any out xmit fxp1
> 65535  1659  185195 deny ip from any to any
> 
I don't believe that just removing rule 75 fixes the problem.
Please add the following (from the stock rc.firewall) two rules
right after the `divert' one and beforeany other:

############
# Only in rare cases do you want to change these rules
$fwcmd add 100 pass all from any to any via lo0
$fwcmd add 200 deny all from any to 127.0.0.0/8

Let me know if this helps.

-- 
Ruslan Ermilov		Sysadmin and DBA of the
ru@ucb.crimea.ua	United Commercial Bank,
ru@FreeBSD.org		FreeBSD committer,
+380.652.247.647	Simferopol, Ukraine

http://www.FreeBSD.org	The Power To Serve
http://www.oracle.com	Enabling The Information Age


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20000131215456.B97751>