Apologies. Should have stated that in original post. Thanks for the reply.
B311 4g router 192.168.8.1 (WI-FI off)
TP-LINK N600 TD-W8980 (On dedicated bridge mode, option for it) 192.168.1.1
Asus DSL N16 192.168.2.1
"Three B311 -> TPLink -> TPLink -> Asus" This is correct.
From the research i've done, DHCP has come up a lot. I know nothing about it to be honest. I've tried switching it off on the Asus router but leaves me with no internet or unable to assign an ip address to devices (if connected to the asus). I thought the tp-link would have assigned an ip address but don't think it works like that.
Though i've changed all routers lan ip addresses which i'll state above.
To add: If i swap the asus and the tp link i also get normal speeds. Like the technicolor.
The Tp link is connected to b311 using the wan port. The tp link then connects to the asus wan port.
Edited by woodmass14 (Sat 09-Feb-19 16:00:28)