Problems with "Microsoft DirectAccess"

[#1]

Hi Phil
Sorry to hear you're moving on - thanks very much for your help in progressing our problem.
Best of luck with whatever you're moving on to, and Happy Christmas
nick

[#2]

To conclude:
We now have DirectAccess working OK on our plusnet connection.  The thing which seemed to be causing the problem was the IP address that I had been allocated. My account was originally set up with a fixed static IP address (one starting 80.x.x.x).  One of the tests done was to allocate me a different fixed address (an 81.x.x.x) address - this failed as well.  Then the account was changed so that I was given a dynamic IP address (which appears typically to be 146.x.x.x). This worked. (There were a couple of other things about my account which we thought might have been relevant such as my having the "pro add-on", but these were all eliminated.)
Because I don't actually need the fixed address, I'm happy to have my account changed so that now I'm getting a dynamic address, which works with DirectAccess.
So I (and plusnet) assume the problem is that the 80.x.x.x/81.x.x.x addresses are being rejected/blocked at some stage between my home and the server.  There's no concrete evidence of this so far as I know (e.g. no address blocking going on at firewalls at either end).  If that's right, then if plusnet ever allocate me a dynamic address in the 80.x.x.x/81.x.x.x range then the problem would presumably come back.
But for the moment things are working, so the support call has been closed.  I hope that this may be useful in case anyone else has similar problems. 
I found plusnet support to be very responsive and helpful (even though we didn't definitely get to the bottom of the problem) so I'm hopeful that if the problem does recur we'll be able to get it sorted
nick

[#3]

Though I don't personally envisage using this I'm pleased to hear you got it to work.
Dynamic IPs appear in the policy block list which means they wouldn't normally be serving mail. Fixed IPs aren't in that list, but it isn't obvious (to me at least) why there should be any connection between that list and MS Direct Access. So mentioning this is probably just a red herring.

[#4]

Thanks for the update Nick,
Good to hear it is working.
Personally, I feel this could do with further investigation. Ideally, the conclusion should have been passed up within the networks team, so they can validate it isn't related to the configuration in the core network.
As you say, if you ever get allocated an IP from a range that has issues, this requires you to take action and not just that, due to the way they are allocated, you could just end up with another problem IP. Although simple, you should never need to hop connections just to get access that should "just work".

[#5]

Phil
Yes, ideally I'd like to have got to the bottom of exactly what's wrong but I appreciate it's an awkward one to investigate and so at the moment I'm mainly relieved that the thing's working and that we know that there's no fundamental incompatibility with the use of DirectAccess over Plusnet.
I hope that this will continue to work, but should we see this problem arise in future, at least we have this thread (and the one in Plusnet's support system) to refer to and so we won't be starting all over from scratch.
nick