Strict NAT headache (XBL)

[vertigo]

Howdy!
Quick summary:
On testing connection my 360 tells me my NAT is strict.
I have opened all recommended ports (TCP/UDP 53, TCP 80, UDP 88 and TCP/UDP 3074) and given the 360 a static internal ip (.36) and have checked after rebooting both that it takes the right one despite there being no other devices filling up the numbers in between.
I have no DMZ set as I read it can cause conflicts, although setting the DMZ to the 360's IP had no effect anyway so I removed it.
Having UPnP on or off makes no difference either, I still get told I have a strict NAT.
My router is a Netgear WGT624v3 and I have no choice in that matter.
I'm on Virgin Broadband which I believe uses all manner of proxying and may be the cause of the problem, but again I have no choice in the matter.
Can anyone help me get this sorted?

[EJG1980]

Don't think it's Virgin as I'm on Virgin and I've got an open NAT.

I know you've probably looked but I've got a Netgear router (WNR2000) and there's an option in the WAN setup page to choose between strict and open NAT filtering. Anything like that on the setup page for your router?

[Neil]

I was with Virgin before going back to BT about a year ago. I was constantly having problems with a strict NAT probably every other time I turned my Xbox on.
The only thing I did was to reboot the router which helped for a time and reset the NAT but didn't solve the problem. I found Virgin awful tbh.

[vertigo]

Nope, I've got the following:

WAN Setup

Connect Automatically, as Required
Disable SPI Firewall
Default DMZ Server ...
Respond to Ping on Internet Port
MTU Size (in bytes) [1500]

I tried disabling the SPI firewall and have also disabled the MicroTrends thing, but neither of those have had an effect either.

[Decider-VT]

Virgin isn't causing the problem.

Is your 360 directly connected to the router (i.e. not bridged through a PC or another device)? Have you specified the 360's static IP in the router's addressing table as well as on the 360 itself?

[Dirty Sanchez]

I found turning off the DNZ and specific ports and sticking with just upnp worked for me most consistently.

[EvilBoris]

You got the latest firmware on your router?

[MJ]

I've been with NTL/VM for many years and never had NAT problems once the router has been set up.

With our Linksys WRT54GS with stock firmware I only get an open NAT using auto settings on the 360 and UPnP on the router. Port forwarding and DMZ don't get an open NAT.

With our D-Link DIR-615 with DD-WRT firmware I get an open NAT using a static IP on the 360 and port forwarding on the router. Auto settings and UPnP and the DMZ also get an open NAT with this router and firmware combo.

I have opened all recommended ports (TCP/UDP 53, TCP 80, UDP 88 and TCP/UDP 3074) and given the 360 a static internal ip (.36) and have checked after rebooting both that it takes the right one despite there being no other devices filling up the numbers in between.

When using port forwarding you need to assign the 360 a static IP that is not in the same range as your DHCP addresses, which is what it sounds like you've done. This could be causing conflicts with the port forwarding.

[vertigo]

I found turning off the DNZ and specific ports and sticking with just upnp worked for me most consistently.

This fixed it, which is weird because I only set up all that crap in the first place because it wasn't working with UPnP.
Thanks for the help, everyone.

[vertigo]

Although oddly it now doesn't show the 360 as an attached device even though it's definitely connected to the right network... but let's ignore that as long as it's working.