upc - xbox live mtu not high enough to connect

yelselseivad

Moved to UPC recently and after a number of teething problems all was going well until... xbox live suddenly refused to connect. Error code states the MTU is too low.
Have changed it from 0 (default) to 1400 then 1365 but no joy. Ping etc seems to be fine. UPC helpdesk put me onto 2nd level support once but what they said would work didn't and when I called back they told me to call a premium no which I wouldn't do, then said someone would get back to me, didn't and am waiting to a reply to an e-mail.
Can anyone on this forum help me as I have more confidence in you than UPC.
Kids off school and won't survive the summer if the xbox isn't functioning as well as the fact that our payment for live is just being wasted.
Have a Cisco as supplied by them. Did connect my Belkin N+ router to it to see if that helped but didn't make any difference. Have explored many options need help please

paulm17781

I had this problem with 3 successive routers. A better router fixed it for me. If you have the Cisco all in one modem / router, you could be out of luck.

yelselseivad

I have my old eircom modem and a N+ belkin router can I use them istead or can I buy an replacement that will work if it's the cisco that's causing the problem? Or as UPC say they don't support xbox do we have to wait till we're out of contract so we can change supplier. Can't understand why it's stopped working when it was working is it something the kids did to the xbox or is it a upc issue?

Knasher

I specifically don't have the cisco router myself, but I'd imagine you should be able to set it up in bridge mode and then plug your old N+ router into it. You should also disable the firewall and the flood detection on the cisco (as your old router will be doing those things now) and then see if that helps. I've heard a lot of people complaining about the cisco so it wouldn't surprise me if your problem lies there.

I'm not 100% sure how the cisco routers work, but its my understanding that they can download firmware from the internet and update themselves from that, so its plausible that a firmware update broke your xbox settings without any interaction from you or your kids.

Just out of a matter of interest I assume that you are adjusting the mtu on the wan connection on the router itself. Also that MTU seems a little low, my understanding is that while dsl has some overhead and needs an mtu of 1492, cable doesn't have that issue and defaults at 1500. Try setting it to that instead.

Karmafaerie

You do realise OP that no IP will support your Xbox live connection, right?
Don't think that changing to another provider will give you better support.
Set up port forwarding on the Cisco for Xbox live if you haven't already.

yelselseivad

How do I set up port forwarding? Is there a link or can you tell me what to do? Still can't understand how this did work and now it doesn't. Got e-mail from UPC to say they'd call me last night to resolve but they must have been busy and didn't get around to calling. Would be great if I could get this fixed. Thanks

wcarey1975

Everything you need to port forward should be located here. I have used these for all of my modems/routers so hopefully yours is there.

W

yelselseivad

Unfortunately not, that's the problem I keep seeming to come up against. Its obviously not used/available in the US which is where most of these 'help' sites seem to be so I can't find out how to fix it. Doesn't say on the cisco european site whether it's compatible can't find a way of e-mailing them to ask, link from xbox was for US routers...... keep hitting a brick wall