I have BT fibre broadband but with Vigor 2860 all Facebook, Instagram and sometimes YouTube videos buffer badly. I have fiddled with all settings but just can't sort it, unless anyone here can help

If I access through the BT Homehub they work perfectly.

I can set the BT Homehub up to act as a modem only so can I then connect it to my 2860 to be the router only? i.e. not use the modem in the 2860.

Thanks

If the BT Homehub allows you to put it in Bridge Mode, then yes - connect it to WAN2 on the 2860. Disable WAN1 and turn on Hardware Acceleration.

I'll be amazed if it makes any difference though - the problem is most likely to lie in the 2860 (incorrect MTU, DoS defence triggering, that sort of thing).

(Draytek Routers send all their diagnostic information to Syslog. In theory, you can view the log from the Router's GUI - but I've always found that to be hard work. Better, is a PC running Draytek's SyslogRD).

Some settings to check for issues with video in general - WAN MTU (and check it), IGMP Proxy enabled on WAN1, hardware acceleration disabled, disable sessions and bandwidth limits, disable UPnP (as it should be anyway).

Also check for that old friend the duplex mismatch for any downlinks to switches and/or APs.

A few questions ref last answer as I really would rather continue with the 2860

WAN MTU (and check it) - what should this be set to?

Also check for that old friend the duplex mismatch for any downlinks to switches and/or APs. - could you clarify? Not sure what to look for?

Thanks