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Port forwarding stopped working after moving DHCP from router to a server
Hi.
I have had remote desktop ports working fine through our router (from the Internet) for years actually.
When I changed the DHCP server from the router to a internal Windows server... now I ca...
> The R6300 gets a 192.168.0.3 address from the LAN side of the cable
> modem. [...]
Then that's not a cable modem; it's a cable modem+router, you are
cascading two routers, and the resulting "double NAT" is defeating your
attempts at port forwarding (on the inner router).
> [...] The cable modem on the Internet side gets the public IP. [...]
Because it's a modem+router, not a simple modem.
With only one NAT router, this stuff could work (with changes). The
obvious choices are (1) disable the router in the cable modem+router,
making it a modem-only, and use the R6300 as the router; or (2) do the
port forwarding on the router of the cable modem+router, in which case,
it might be better to configure the R6300 as a wireless access point.
> [...] It has worked for years and now nothing "port forwards". [...]
I can believe that it worked if you had one router, and not two
routers. Now that you have two routers, you're approximately doomed,
until you return to an arrangement with only one router.
So, nothing to do with any DHCP server anywhere. (Although, a
one-router/one-subnet configuration may change your DHCP server
requirements from what they are now to something simpler.)
Hi.
Firmware: V1.0.2.80_1.0.59. It's actually a R6300
Yes, publish = port forwarding
There is remote desktop, 2 web pages (two different servers), but that's about it. (all stopped working)
Verified the IPs on the devices indeed match the IP reservations on the DHCP server.
My assumption is that the devices just need the router as the gateway? And that is what I have set in the DHCP scope options... the router IP is the gateway in the DHCP scope options. And verified in the device's IPConfig.
The R6300 gets a 192.168.0.3 address from the LAN side of the cable modem. The cable modem on the Internet side gets the public IP. My port forward for example, for a remote desktop is incoming port of 3389 and goes to the internal IP of a desktop:
Service Name My Remote Desktop
External Start Port 3389
External End Port 3389
Internal Start Port 3389
Internal End Port 3389
Internal IP address 10.0.0.177
The R6300's LAN address is 10.0.0.1 (and all devices have that as the gateway of course).
That's an example port forward rule. It has worked for years and now nothing "port forwards".
I also verified the firewalls on the devices have the needed ports open - for example 3389 on the one listed above. I've also tried to disable the PC's firewall as a test - same result.
> The R6300 gets a 192.168.0.3 address from the LAN side of the cable
> modem. [...]
Then that's not a cable modem; it's a cable modem+router, you are
cascading two routers, and the resulting "double NAT" is defeating your
attempts at port forwarding (on the inner router).
> [...] The cable modem on the Internet side gets the public IP. [...]
Because it's a modem+router, not a simple modem.
With only one NAT router, this stuff could work (with changes). The
obvious choices are (1) disable the router in the cable modem+router,
making it a modem-only, and use the R6300 as the router; or (2) do the
port forwarding on the router of the cable modem+router, in which case,
it might be better to configure the R6300 as a wireless access point.
> [...] It has worked for years and now nothing "port forwards". [...]
I can believe that it worked if you had one router, and not two
routers. Now that you have two routers, you're approximately doomed,
until you return to an arrangement with only one router.
So, nothing to do with any DHCP server anywhere. (Although, a
one-router/one-subnet configuration may change your DHCP server
requirements from what they are now to something simpler.)