Re: iptables port forwarding fails when adding third NIC (r8169) Kernel: 2.6.17-1.2174_fC5


OK Guys,

It's taken me a while, but I've build a completely separate machine
with a nearly identical setup that allows me to test away, ant that I
have been. I have confirmed all my previous statements.

Here's the base problem: I start with a machine with two NICS and
existing firewall rules that handle port fowarding from outside the
firewall to services inside the firewall. These services are known to
work. I add a third NIC, and port forwarding ceases, without error.

None of the firewall rules are changed, and the drop log doesn't show
any packets getting dropped.

I have run tcpdump and can confirm that the packets are getting to the
router machine but are not making it past. Port forwarding is turned
ON, of course.

This is CentOS 2.6.9-42.0.8.EL

Paul

On Jan 26, 3:00 pm, Robert <n...@xxxxxxxxxxxxxxx> wrote:
On Sat, 20 Jan 2007 20:43:37 -0800,Paulwrote:

Sorry for the delayed reply.

Yes, it's true the interfaces were renumbered when I added the third
card. Like I said in my original post, the new card claimed eth0,
which left eth1 and eth2 for the LANA and LANB ports built into the
motherboard.

I rearranged the cabling to reflect this change. I also verified
connectivity by performing ping tests on all interfaces.

Can you run tcpdump on this machine? It might tell you something. I
don't see how adding a nic will cause forwarding to stop working unless
it's forwarding out the wrong interface.

--

Regards
Robert

Smile... it increases your face value!

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----http://www.newsfeeds.comThe #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----


.

Relevant Pages

  • Re: ipfw and tun0
    ... > interface" when writing firewall rules, setting up NAT, etc. ... "real" NICs and if I activate firewall rules that drop packets from ... > behind the firewall, either tcpdump on a client machine, or tcpdump ...
    (freebsd-questions)
  • Port forwarding
    ... I have SBS 2003, 2 NICs. ... The internet IP of the router changes, ... I have enabled the telnet service. ... I have enabled the port forwarding on the router to forward telnet ...
    (microsoft.public.windows.server.sbs)
  • Re: Tool for working remotely with two PCs connected both via NAT-routers
    ... I know about the problem of port forwarding to make this conception work. ... up forwarding rules? ... any access to configure firewall rules. ... For example, if you have a look at Skype messaging, the problem should be ...
    (microsoft.public.windowsxp.work_remotely)
  • RWW Problem
    ... The server is a single nic, but has another nic enabled for the ... It has a a pair of Broadcom nics and a pair of Intel ... I do know that port forwarding on the router is correct. ... ciecw wizard but I am unable to find anything. ...
    (microsoft.public.windows.server.sbs)
  • Re: port forwarding
    ... We have Windows 2003 Server w/2 NICs. ... Can I setup public ip address port forwarding to different computers and How? ...
    (microsoft.public.windows.server.general)