How can I get two Xbox 360's to be in "open nat" mode behind the same router?
To avoid some confusion for future readers, this is what at least got me to two "moderate" NAT's on the 360's, which is good enough to find games together:
- Use DHCP on both 360's
- Specify hostnames for both 360's (in the advanced tab in network settings)
- In DD-WRT, assign reserved/static IPs for the MAC+hostname of those 360's outside of your DHCP range
Occasionally somehow we end up with red NAT again, and I turn off both 360's, clear the uPnP table in DD-wrt, and turn on the one who had red NAT first, then turn the other one on 20 seconds later...
It's not a permanent fix, but it seems to work decently.
You should be able to get Open NAT on multiple Xboxes as long as your router has a good implementation of UPnP. Microsoft used to have an Xbox LIVE compatible hardware list (archive link) which said:
All of the network hardware in the following lists works with multiple Xbox 360 consoles connected at the same time.
Although not being on the list doesn't necessarily mean your router won't work. Obviously MS is testing with OEM firmware. I don't know how good DD-WRT's UPnP is - you could perhaps try OpenWRT.
To recap, you should configure your router:
- DMZ off
- port triggering off
- no Xbox-specific ports forwarded
- UPnP on
- DHCP server on - you don't need address reservation
- NAT enabled obviously (if it's even optional on your router)
Configure the Xboxes:
- IP Settings: automatic
- it might help to give each Xbox a (different) Host Name under Additional Settings; I don't know what protocol this setting affects, and the xbox website isn't telling me.
This answer was originally posted for a question that is probably a duplicate of this one:
Usually, port forwarding issues on the 360 are solved by forwarding ports to a specific IP address. I can tell you from prior research on this topic that you can't forward ports to multiple IP addresses with one router.
The easiest thing to do would be to forward the appropriate ports to one box, and then put the other box in the DMZ. The DMZ puts the box outside the firewall, which is a security risk. That being said, I've had a 360 in the DMZ for years at a time without any issues. This is the current setup I'm using with my Xbox 360 in the DMZ, and my Xbox One with forwarded ports.
Another possible approach would be to get a 2nd router, forward the ports to that router, and put both boxes on the 2nd router. I haven't been able to get this to work myself, but I'm told it should be possible. This would be more secure, if you can get it to work.