XBOX 360 live MTU problem

[#1]

My son is trying to connect his XBOX 360 to xbox live.  Each time he tries the test connection it fails saying that the "MTU setting is not sufficient and requires a minimum MTU of 1364".  It is connected via ethernet to a zyxel router which has an MTU of 1500.  Does anyone know how to fix this?

[#2]

you cant set the mtu on the xbox but with the router being set at 1500 am abit  at why its doing this.
have you tried doing a hard reset of the router to see if that clears anything?. are you runing the latest firmware on the router?

[#3]

Router hasn't been up very long due to all my other troubles (see my other threads for details).  The firmware is latest.  I suspect the MTU error message is a red herring but can't be sure.

[#4]

Hi Mapletree,
I used to have a similar problem on a different ISP with my Netgear router - I ended up having to re-flash the firmware on the router, and then it mysteriously started working again. Never worked out what caused it

[#5]

Thanks for the comment.  I doubt the problem is with my firmware since In have no other IP problems.

[#6]

Mapletree,
No worries - I will just say that when I was having the 360 issue, I had absolutely no other problems on my network or with my internet connection whatsoever.
Hope you get it sorted!

[#7]

You could try setting the router to an MTU of 1430 and see if that helps. Sometimes it does..

[#8]

I've done some more searching and it looks like xbox live needs some non-standard ports opening.  My router's firewall table is already full so I think, even if I solve the MTU problem, it's not going to work.  Also I think lowering the MTU would break other things. 
Personally I can't think of any situation where lowering the MTU on the router should help.  All it would do is to fragment larger packets.
UPDATE: Lowering MTU to 1430 makes no difference.

[#9]

uPNP should take care of the xbox ports. The ports that need opening are 3074 udp/tcp and also 88 udp all thoe i think its fine to just make sure 3074 is open

[#10]

Quote from: mapletree

My router's firewall table is already full

And I don't have upnp (and wouldn't enable it even if I could)

[#11]

cant u then give the xbox a static ip on your router and dmz this ip?

[#12]

I've just swapped my router over to try and sort out another problem.  This one does not allow a fine control over the firewall.   It works with xbox live though.