I reset the router and it created that odd atm0 interface automatically, so I removed all traces and set up the connection from scratch (it would not let me edit it).
The problem persists, however something odd that has occurred is Facebook.com loads quickly whereas all other sites tried seem to connect but not load the pages. The speedtest page connected but then tried to load for over 5 minutes with no joy.
I have verified the settings against the Sky hub.
The Default gateway matches.
The DNS servers match.
The Sky hub shows a different "Broadband Port IPv4" address to the "IPv4 WAN IP Address" in "Internet Info" on the TP-Link. - Does this matter?
I noticed this in the maintenance page too:
Test the connection to your Internet service provider
Test PPP server session: PASS
Test authentication with ISP: PASS
Test the assigned IP address: PASS
Ping default gateway: FAIL
Ping primary Domain Name Server: FAIL
Test the connection to your DSL service provider
Test ADSL Synchronization: PASS
Test ATM OAM F5 end-to-end ping: PASS
Edited by beercan (Sun 26-Jul-15 13:29:15)