same port forwarded to different ips - No?

[stsalkit]

Hello to all. I am a brand new owner of RT-N66U and obviously still learning. I went through the pages of the forum but did not manage to find an answer to the following question:
- I want to forward the same port (80) to two different IPs in my network. Following the "add" action for the first IP, when I type the specifics of the second one and I press the + button, I get an error message "This entry has been in list" and highlights the 80.
This is something I have not seen before - can someone direct me to a solution?
Thank you in advance

 

[RMerlin]

This is not technically possible. A TCP connection can only come from one single source, and connect to one single destination.

 

[SloPoke]

That's the way port forwarding works: you can only forward a port to a single ip address on your LAN. If you're setting up web servers on two different machines on your LAN, you'll have to change the listening port for one of them, and then have that port forwarded through the router.

 

[stsalkit]

This is not technically possible. A TCP connection can only come from one single source, and connect to one single destination.

Thank you for the reply. I am not technically savvy, but this is what I was declaring in my old Linksys and it had no issue. I actually want to port forward 80 for an Xbox360 and a satellite receiver (dreambox) - they both listen to the same port. I can see no way of changing to either the port the listen for! Any suggestions as to how to overcome this issue?

 

[RMerlin]

Thank you for the reply. I am not technically savvy, but this is what I was declaring in my old Linksys and it had no issue. I actually want to port forward 80 for an Xbox360 and a satellite receiver (dreambox) - they both listen to the same port. I can see no way of changing to either the port the listen for! Any suggestions as to how to overcome this issue?

If the Linksys allowed you to forward to two different IPs, then only the first one was working - there is no way for the router to tell if an incoming connection on a specific port is meant for device #1 or device #2.

Port forward is only needed for incoming connections. Does the XBox360 really run a web server that can be remotely accessed? Why do you want to forward port 80 to either of these two devices?

 

[linkmaster]

Was it port forwarding that you did previously or port triggering?

 

[stsalkit]

If the Linksys allowed you to forward to two different IPs, then only the first one was working - there is no way for the router to tell if an incoming connection on a specific port is meant for device #1 or device #2.

Port forward is only needed for incoming connections. Does the XBox360 really run a web server that can be remotely accessed? Why do you want to forward port 80 to either of these two devices?

This port (80) is quoted as requirement for xbox live to work, in Microsoft's website, along with ports 53, 88, 3074

On Linksys I was doing port forwarding not triggering!

Regarding the Dreambox, this port should be open in order to reach remotely its webpage for programming recording timers etc.

I am not disputing what you both say, but the strange thing was that apparently having the same port being listened by two devises it worked! I had no problems with either xboxlive nor dreambox!

 

[Nerre]

It could not have been working. As they said, it's technically impossible.

If a request comes from the outside to port 80, how would the router know if it was to go to the xBox or the Dreambox? If it is sent to both, and both respond, which answer should the router forward to the outside client?

The way tcp/ip works it is not possible to forward one port to more than one ip.

I don't think the xBox need the forwarding, that's why you think it worked. It probably only worked for the dreambox.

 

[stsalkit]

It could not have been working. As they said, it's technically impossible.

If a request comes from the outside to port 80, how would the router know if it was to go to the xBox or the Dreambox? If it is sent to both, and both respond, which answer should the router forward to the outside client?

The way tcp/ip works it is not possible to forward one port to more than one ip.

I don't think the xBox need the forwarding, that's why you think it worked. It probably only worked for the dreambox.

OK. Thank you very much for your time! A quick question on a different topic. As I said I just purchased the RT and it runs version .260. From checking in ASUS website I saw that a new release is out which I would like to update the router with.
The question is: when I upload the new firmware, do I need to re-enter all current settings or it keeps them? or import them from a saved settings file?
(I could not find instructions related to the firmware update). Thank you again!

 

[Nerre]

I'm not sure if settings are retained, but there should be a possibility to back up the settings.

I'd also recommend using the Merlin version of the firmware.

 

[RMerlin]

This port (80) is quoted as requirement for xbox live to work, in Microsoft's website, along with ports 53, 88, 3074

This is outbound, not inbound. You must not forward any of these ports. Port 53 is for DNS queries for instance - your XBox only makes outbound connections to DNS servers.

 

[RMerlin]

The question is: when I upload the new firmware, do I need to re-enter all current settings or it keeps them? or import them from a saved settings file?
(I could not find instructions related to the firmware update). Thank you again!

No need to reset to factory defaults when going from 260 to 270 (the recommended version). All your settings will be preserved.

It is not mandatory if going to 370, but recommended. However be aware that 370 has issues on the 5 GHz band in 40 MHz channel width - 270 is the most stable at this time.