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I have a Zyxel P-661HW-D1 modem/router with several port forwards that works on the WAN interface. I'd like to make them work for the LAN interface as well, like I'm used to.
I updated the firmware to the last version I found (V3.40(AHQ.4) | 07/08/2009) and I activated the nat loopback option from the command line, that should enable the desired behaviour. The loopback seems to be active after rebooting the router as well, as I can get this response from the CLI:

ras> ip nat loopback
NAT loopback: on

Still, the port forwards don't work inside the LAN.
E.g. I have a server on that I can't reach by (router's LAN ip) nor by <WAN IP>:5000.
Such server is only reachable by <WAN IP>:5000 from a machine that is outside the LAN.

share|improve this question
Do you have more than one router in your network? – David Schwartz Dec 17 '12 at 18:07
@DavidSchwartz no, and with my old router (I switched to this one recently) it worked fine – etuardu Dec 17 '12 at 18:30

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