Funny fault

[#1]

I was unable to access anything on the Plusnet or Madasafish sites and could not ftp into my website or use email but could access the rest of the internet just as normal.
I followed a googled article and used tracert in command mode and after 7 hops it started to time out, with the final destination being at a plusnet address.
Fortunately we have two accounts between son and me with his working fine so I could get by.
Plusnet started to check it out and I was advised that it was an Openreach problem. The Openreach engineer phoned me the next morning but by then it was working again and we decided it would be a waste of his time coming out as he would get on the ferry at 10:00am and not get back until 5:00pm.
Of course the fault returned but it also affected the second account in the same fashion. Both accounts came back on again later but the question is did Plusnet repair it or is it an intermittent fault.
It would be handy to know

[#2]

Strange that it was only the Plusnet sites that you couldn't access, that seems very odd.
I'm going to be honest, I'm a bit lost as to what this might have been so can't really say either way where the issue lay.

[#3]

Got to be a problem and raised a ticket at the beginning of this month
Just had 5 days with no problems and now the fault is back again! No connection to any site starting with 212. Openreach said that they had rectified a fault in the local exchange that may have been the cause a few days ago.
Could the fact that I upload a couple of images, total about 70kb per minute affect anything?  
Just swapped router to another Draytek 2820n but no difference.
Could it be a fault affected by that particular model of router? I have some spare Belkin routers which I could try, or would I be wasting my time?.
I

[#4]

Quote from: jorvikmik

No connection to any site starting with 212. Openreach said that they had rectified a fault in the local exchange that may have been the cause a few days ago.

Undertaking tracert diagnostics (or pathping) to somewhere like plus.net would be useful here.
212.*.*.* is a massive range of addresses - a refinement of this (for example 212.159.*.* one of PlusNet's subnets) would be very helpful.
I very much doubt that any thing done in the local exchange would impact traffic routing from you to the internet, as all onward routing is performed on PlusNet's premises.  Anywhere you try to connect to have to go through PlusNet's gateway and be routed onwards.

[#5]

I think I know what is causing this but let me check.

[#6]

Was your thought correct?

[#7]

I have no idea what mysterious issue Matthew has found, I'll go throw things at him to get a reply.