Publishing a port through a NAT on 837 does not work

[graham]

Hi,

I am trying to publish two ports through an 837 so these ports are available from the Internet interface. The WAN/Internet side has a single ip address 84.9.xx.yyy. I am trying to publish two specific ports only from a specified LAN machine to this WAN side address 84.9.xx.yyy.

I followed every example I can find but have been unable to get anywhere. I am testing it from the LAN using the external/WAN ip address and just get 'the connection was refused'. Nothing is visible in the router or firewall logs to tell me what is happening. Showing the dynamic NAT mappings does not give a clue.

Does anyone have any ideas where I am going wrong?

Thanks for your help,

Graham

Configuration of 837 attached

[lgijssel]

You should test this from the outside. Can't you establish a dial-up or something like that?

I looked at your config and all required items are there, doesn't seem to be too much wrong with it.

I suppose that Internet access is already working?

Please test it properly, i.e. from the outside. If it also works from the LAN, consider that a bonus.

Regards,

Leo

[graham]

Hi,

Yes it is OK from the outside. How do I enable some form of loopback processing or address decoding so I can see it from the inside? This is important because of the port mappings I will be adding.

Thanks.

Yours,

Graham

[lgijssel]

You should use inside adresses in that case. You can only do NAT when the packet traverses via nat inside to nat outside or vice versa. nat inside to nat inside will not work. Your problem might be name resolution? You could set up a separate dns that is checked first but only accepts requests from inside hosts. This server should only resolve inside hosts and forward all other requests to an internet dns. In this way you can use the same url for in- and outside.

Regards,

Leo

[graham]

Leo,

Yes I would like to but I am remapping ports so a simple DNS lookup will not work.

I would like to use the loopback if I can with the DNS to generate a dummy external address that will see a parallel remapping to this other DNS address but I have not been able to get the loopback working to do this.

Thanks for your help.

Yours,

Graham