Our site has been down since yesterday morning 10am until today 1000am due to network problem which IS have linked to a faulty link with a campus switch.
IS have temporarily disabled the physics link to the library switch, one of our two links to the network, and this has fixed the connectivity problem from the outside world to our grid box.
They will re-instate the link (for resilience) when they've got to the bottom of the problem (faulty fibre, or whatever).
So, it'be interesting to see the gridmon result in the current configuration while waiting for IS to understand the problem.
This may be the cause of the 33% UDP Packet loss we have been seeing to/from birmingham.