I was doing a bit of scanning on my network lately, knew all the hostnames to each computer connected. But whilst pinging one of them ping returned Request timed out.. This is strange as I know the computer is online and that the computer responds correctly to pinging on a different (enterprise) network. Is there something on the computer, my network, or my computer that is bugging with this? – That's just a sub-question, I don't expect this to be the main answer.
The real question: Why does this happen? Why does pinging the IP4 address not work?
EDIT :
Pinging the Hostname used to default to the IP4 address, but now it defaults to the IP6 address. Why does this happen? But now that it pings using IP6, how come it all of a sudden works?
> ping -6 THE_COMPUTER
Pinging THE_COMPUTER [lengthy IP6 address] with 32 bytes of data:
Reply from [lengthy IP6 address]: time=1ms
Reply from [lengthy IP6 address]: time=1ms
Reply from [lengthy IP6 address]: time=1ms
Reply from [lengthy IP6 address]: time=1ms
Ping stats: Sent = 4, Recieved = 4, Lost = 0 (0% loss)
But when this is done using IP4 it doesn't work. So there are now two questions:
- How come IP6 works and not IP4?
- Why does IP4 not work?
Best Answer
there are a few things I would recommend you try to see if you can fix this:
Disable windows firewall if you have not done so already. It is a fairly well documented "feature" of windows firewall that it randomly blocks packets even if an exception is made. Look on Technet and you will see what I am on about!
Disable IPv6 on your NIC. If you are not using it, it will only cause problems! Especially in situations where both PCs speak ipv6 and the router/switch between them doesn't.
Reinstall your network adapter drivers. Intermittent connectivity cal often be caused by faultering/failing driver installs. Even if it doesn't fix the problem, it definitely won't hurt!
I have often found that the main reason this happens is one of the above... hopefully this will help set you on your way.