xbox live MTU error - NTL - isp

[jigger_jay]

i posted in the live thread but i am not 100% sure a lot of ppl could see it so i made a thread.

serious connection problems i dont know why though.

i am getting the error at the mtu stage.

the mtu is to do with the router afaik, its has to be 1,500 or above a certain number something like 1,368. and i checked the settings and ours is on 1,500.

before anyone says anything, i have had xbox live working with my current setup before, i had it for about 2 weeks then this error came through and i have since then been trying to fix it.

the setup goes like this. Host pc, connects to the internet, the wireless router connects to my pc and my 360 connects via internet connection sharing. afaik the settings are perfect as i aint changed a thing.

the router we use is a linksys wrtsg54gs or something along those lines.

any advice would be much appreciated, i have the router on the latest firmware and i have done the test to see which mtu to set the router at and it said 1,500..

[Mr VCD]

to see what your max mtu is type the following into a command line prompt:

ping jolt.co.uk -f -l 1300

You should be able to get a ping returned, now you can increase the figure on the end until you get the following message:

Packet needs to be fragmented but DF set

Once you see this you've gone past the maximum mtu your connection allows, so drop it back down and set it as this.

If it's been working before and nothings changed your end then it points to a problem with the data carrier i.e your isp :(

[jigger_jay]

i have done that test before and it came up with 1,500

[jigger_jay]

i hear sometimes ntl has errors, but i cant work out if there is anyway of rectifying it ?

[Liggur]

I had the same, but LIVE was down that morning for 3 hours, when I got home, it was all up and running fine again.

[jigger_jay]

mine has not been working for 3 weeks about thought !

[paulsaz]

your setup sounds a bit weird, surely you'd want to connect the router to the internet and your pc and 360 to the router and do away with ics?

[jigger_jay]

the router is at the other side of the house

the modem connects into the router and gives me the interent wirelessly and my 360 connects via ics.

[lsba02853]

May not be of help but my brother in law recently setup Live using NTL.
He got the same error and could only get it to work if he cloned the MAC address of the PC in the Xbox, then bugger me it all stopped working.

Finally got it sorted by phoning NTL and advising them, they knew about the problems people were having and did something their end.

[Smigg]

The reason for cloning the MAC address is to do with what the modem will allow to connect to the internet. Basically most modems will only allow one MAC address to connect, and it will be the first one it detects when the modem starts up. So if your PC is on when you power up your modem, it will be the PC MAC address that the modem will allow through. If you then try and connect your XBox through your modem it will be blocked as, by default, it will have a different MAC address.

This can be gotten around by using something like a wireless router. As the modem is connected directly to that you can then connect your PC and XBox to the router (either wired or wirelessly) and the MAC address on the router pushes traffic from both to the modem, hey-presto, you don't have to do MAC address cloning... :)

I'm guessing the change NTL made pushed something down to the modem to allow multiple MAC address connections...