jezphr wrote: My ISP is Zen internet
MTU is not the same. It is 1520 on the 2762 and something slightly less on the 2830.

Is this ADSL or VDSL/FTTC :?:

I assume the 2830 is using Zen's router in 'bridge mode' and the 2762 is plugged in directly :?:

I have a 2830n working with Zen via a Zyxel (Netflix works) - MTU is set to 1492 (can't remember where I got that from - probably some Zen documentation). You could try that on the 2762.

There's various hints around the Web, that you can use higher values, if there's no Ethernet segment to a separate modem; I don't know if there's any truth in that.

The 2762 has the "Path MTU Discovery" option, but you'd have to ascertain the IP addresses of the Netflix servers, to use that.

I'm on ADSL unfortunately. Too close to the the exchange to get FTTC but that's a whole other story.

I changed the MTU to 1492 and hey presto it works now. Brilliant. Thank you very much for your help.