I have a file server that is hosted with a VPS provider. On aprox 16th Dec 2016 I could no longer ping my VPS from my home internet connection, VirginMedia. This had worked fine previously.
I asked the VPS provider if they began any new filtering, and they said they had not. I asked if they could ping my VM, and they could. Then I tried using a few troubleshooting websites which will ping a host for you -- I tired two and both could ping my VM.
A traceroute from me to the VM shows hop number three, the first outside my LAN which replies, is brig-core-2a-xe-804-0.network.virginmedia.net but after that no pings back.
Similarly I cannot ping home from the VM, traceroute from the VM back to my home WAN IP stops at hop 8, brig-core-2a-ae2-0.network.virginmedia.net.
So, I think VirginMedia is eating pings in both directions, at least between me and this host.
Note, I have another VM at a different VPS provider in a different data centre and pings are still working fine both directions.
I think we should watch out that our internet providers do not silently start to break standard internet protocols in some attempt to (I'm guessing here) reduce botnet activity.
Granted, some extreme measures may need to be taken, but then a mechanism needs to be in place to get yourself whitelisted or at least fully informed.
If any Virgin Media network engineers are reading, please let me know. I can't imagine a call to tech support by me would do any good.
I can give more details in a PM.