That makes two of us. I must try and get 1500 MTU, maybe if i telnet in and do it that way ill get it but its raid time in WOW so must go do my duty.

You dont need to telnet any more to change the MTU its now on the WEB interface on the WAN internet access screen for each WAN. I just checked mine and it was set at 1442 so hence I did not see any speed reduction.

Howard Simpson wrote: I just checked mine and it was set at 1442 so hence I did not see any speed reduction.

Excellent - so thats why maybe yours was OK after the upgrade. You already had a lower MTU.

I am not a brainbox in this area but can anyone work out why or how this bug is occurring and its relation to the MTU setting? Its very odd.

The MTU for ADSL should never be higher than 1492. 1500 is for cable/ethernet. It can vary from ISP to ISP and for all sorts of reasons. If you want to check the optimum size, have a look here .

I have a feeling it sometimes needs to be even lower than that for some web sites but I am not sure.

The low values folk are having to use seem more like MSS values than MTU to me.

Haven't Draytek traditionally used MSS for the router setting. Perhaps they've suddenly changed to MTU with the latest firmware.

I just did an upgrade from 3.3.3 to 3.3.4.1 using the reset image. MTU is set to 1442 by default (max is shown as 1492). I didn't notice any reduction in ADSL speed (so far)