Double NAT & HTTPS Connection Timeouts

leeharris · 02-02-2011, 10:02 AM

Hi,

I am having a problem with HTTPs in a double NAT'd network configuration. The scenario is like this...

Code:

LAN A 192.168.10.x             LAN B 10.0.0.x
         |                            |
         |                            |
        eth0 ----- LINUX ROUTER ---- eth1
                        |
                        |
                       eth2
                        |
                LAN C 192.168.1.x
                        |
                      NOKIA FW
                        |
                        |
                      Internet

On the LINUX ROUTER, I have configured routes between LAN A and B and port forwarding is enabled. Machines on these LANs can talk to each other no problem. There is also a NAT rule configured for traffic going from LAN A via LAN C out to the Internet. The Nokia is also doing NAT'ing. Normal web browsing works fine with this setup, but whenever I try to access HTTPS sites, it just hangs and eventually times out. Packet captures have showed lots of TCP Retransmission messages. If I logon directly to the Linux Router and fire up a browser, I am able to access HTTPS sites without any problems. This appears to be something to do with the traffic being NAT'd twice. Is there a way I can get around this without changing the config of the Nokia?

Thanks

TimothyEBaldwin · 02-17-2011, 01:49 PM

Double natting can't break HTTPS more than HTTP. Is some configuration specific to port 80 or port 443.