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I've got the following network:

 ADSL(10.) --- Router (, --- "HTTPServer ("
      --- "HTTPS Server" (
      --- Another computer (

I configured my ADSL router to forward HTTPS to (HTTPS server) and it works perfectly fine.

Now I'm trying to do the same thing for HTTPServer ( so I configured my ADSL modem to forward HTTPS to and configured (Router) to forward HTTP to (HTTPServer).

This still works but insanely slow. I know that the router is fine because if I access to HTTPS port of the router from it works fast, but when I access it over the ADSL modem it's getting really really slow (it works but keeps timing out and every request takes seconds).

I can't change my network design (that separate LAN is in there for security), why do you think this is an issue. Why there is performance problem when it goes through

ADSL - Router - HTTPServer


My router : Netgear Prosafe FVG318

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It could be a MTU problem. I would suggest to take a trace with tcpdump/wireshark on and on a client computer on internet to compare them and see if fragmentation is done somewhere.
What kind of modem/router "ADSL" is ? How is he connecting to internet (PPPoE?, ...)

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The "really really slow" immediately rings a bell. Force full duplex on both ADSL and Probably one of them auto-negotiated to half duplex (and is now ignoring incoming packets when transmitting anything, causing a wave of TCP retries).

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I would have problem when performing test from, no ? – radius Jul 8 '09 at 19:53
errrrrrr... true :/ – kubanczyk Jul 8 '09 at 19:58
I was meaning 'he' of course. Anyway it's a good point to check. – radius Jul 8 '09 at 20:06

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