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Date:      Tue, 14 Sep 1999 19:23:36 +0300
From:      Ruslan Ermilov <ru@ucb.crimea.ua>
To:        Doug White <dwhite@resnet.uoregon.edu>
Cc:        hackers@FreeBSD.ORG
Subject:   Re: Multiple NAT alias addresses
Message-ID:  <19990914192335.A3257@relay.ucb.crimea.ua>
In-Reply-To: <Pine.BSF.4.10.9909140846130.65695-100000@resnet.uoregon.edu>; from Doug White on Tue, Sep 14, 1999 at 08:49:21AM -0700
References:  <19990914040220.B71293@relay.ucb.crimea.ua> <Pine.BSF.4.10.9909140846130.65695-100000@resnet.uoregon.edu>

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On Tue, Sep 14, 1999 at 08:49:21AM -0700, Doug White wrote:
> On Tue, 14 Sep 1999, Ruslan Ermilov wrote:
> 
> > > hello ..
> > > 
> > > We're trying to turn up a firewall box running NAT with multiple external
> > > IPs.  I added the alias and set up natd.conf as follows:
> > > 
> > > use_sockets yes
> > > same_ports yes
> > > #
> > > # machine1 redirections 
> > > #redirect_port tcp 192.168.2.237:ssh 1.2.3.4:ssh
> > > #redirect_port tcp 192.168.2.237:smtp 1.2.3.4:smtp
> > > #redirect_port tcp 192.168.2.237:pop3 1.2.3.4:pop3
> > > #redirect_port tcp 192.168.2.237:imap4 1.2.3.4:imap4
> > > 
> > > # machine2 redirections
> > > redirect_port tcp 192.168.2.201:ssh 1.2.3.5:ssh
> > > redirect_port tcp 192.168.2.201:http 1.2.3.5:http
> > > 
> > > I start natd with:
> > > 
> > > natd -f /etc/natd.conf -n fxp0  where fxp0 is the public-side interface.
> > > 
> > > Restarting natd with this configuration causes it to block everything.
> > > 
> > So, without redirect_port's it works OK?
> 
> Yes, and the redirect_port's work if the alias address is not specified.
> 
Strange, I just run 3.2-RELEASE's natd(8) with your configuration file
and everything works as expected:

Firewall rules were:
00001 divert 8668 ip from any to 1.2.3.5 via fxp2
00001 divert 8668 ip from 192.168.2.201 to any via fxp2

Natd(8) was run as:
natd -v -f natd.cf -n fxp2 (fxp2 in an external interface)


telnet 1.2.3.5 123 (from 212.110.138.4):
In  [TCP]  [TCP] 212.110.138.4:49964 -> 1.2.3.5:123 aliased to
           [TCP] 212.110.138.4:49964 -> 1.2.3.5:123
In  [TCP]  [TCP] 212.110.138.4:49964 -> 1.2.3.5:123 aliased to
           [TCP] 212.110.138.4:49964 -> 1.2.3.5:123
In  [TCP]  [TCP] 212.110.138.4:49964 -> 1.2.3.5:123 aliased to
           [TCP] 212.110.138.4:49964 -> 1.2.3.5:123
Redirections not happening.



telnet 1.2.3.5 80 (from 212.110.138.4):
In  [TCP]  [TCP] 212.110.138.4:49960 -> 1.2.3.5:80 aliased to
           [TCP] 212.110.138.4:49960 -> 192.168.2.201:80
Out [TCP]  [TCP] 192.168.2.201:80 -> 212.110.138.4:49960 aliased to
           [TCP] 1.2.3.5:80 -> 212.110.138.4:49960
In  [TCP]  [TCP] 212.110.138.4:49960 -> 1.2.3.5:80 aliased to
           [TCP] 212.110.138.4:49960 -> 192.168.2.201:80
In  [TCP]  [TCP] 212.110.138.4:49960 -> 1.2.3.5:80 aliased to
           [TCP] 212.110.138.4:49960 -> 192.168.2.201:80
Out [TCP]  [TCP] 192.168.2.201:80 -> 212.110.138.4:49960 aliased to
           [TCP] 1.2.3.5:80 -> 212.110.138.4:49960
Out [TCP]  [TCP] 192.168.2.201:80 -> 212.110.138.4:49960 aliased to
           [TCP] 1.2.3.5:80 -> 212.110.138.4:49960
In  [TCP]  [TCP] 212.110.138.4:49960 -> 1.2.3.5:80 aliased to
           [TCP] 212.110.138.4:49960 -> 192.168.2.201:80
Redirections are happening.



> > Have you tried to run it in the foreground? (`natd -v')
> 
> Not on the target machine but I did test it from home.  It looks like NAT
> stops matching packets when the alias addr is provided; it lets them fall
> through to the local system, where they generally get 'connection
> refused'.  I am going to try it without alias addresses for the default
> address (the first bank) and see if those work.
> 
> I can't attach gdb to a running -g'd version of natd, it just segfaults.
> :(
> 
This is a known problem, it is fixed in -STABLE:

dfr         1999/05/22 01:29:24 PDT

  Modified files:        (Branch: RELENG_3)
    contrib/gdb/gdb      solib.c
  Log:
  MFC: Problems with coredumps from static programs.

  Revision  Changes    Path
  1.3.2.2   +1 -1      src/contrib/gdb/gdb/solib.c



-- 
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


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