Strange issue with network in one class

[the_quick]

Hi Guys

 

Maybe someone can shed some light on our strange issue.

 

Today morning all computers in one classroom decided to be pinged. Can't ping them from any computers, including servers. Tried to fix it with cleaning dhcp and dns records - nothing.

They do appear on network search, but can't ping them. They do not appear on Lanschool either.

 

But if you login on those computers , they seem to be fine, no problems with browsing network and internet. Windows firewall is sett to allow pings through and everywhere else is fine, just this one classroom.

 

Teachers computer there is fine. Checked switches, all good.

 

Not sure where could lie the problem. Next thing to try, will rebuild one PC and see.

 

Thanks in advance

[Michael]

How about disabling the Windows Firewall as a test?

[jonnykewell1]

can you ping out from the machines to other computers/switches?

[the_quick]

Will try with disabling firewall.

 

Yeah, machine in question works fine, pinging etc, just not to them.

[Michael]

Will try with disabling firewall.

 

Yeah, machine in question works fine, pinging etc, just not to them.

 

It does definitely sound a firewall issue to me.

[SovietRussia]

ICMP disabled?

[the_quick]

Ping was enabled (Firewall settings) by GPO. All other computers in school work as intended, I have not put anything new on them, just weird. I know nothing just happens, some one must have done something. Need to find a source. Really strange.

Will check firewall over lunch time.

[the_quick]

OK, found the strange issue. Firewall service was disabled, but it was still blocking any pings. Could not started it, unless I added an additional local account in registry key HKLM/System/CurrentControlSet/Services/SharedAccess. The account I have added was mpssvc. And than firewall service would start and computer is back to normal. I checked other computers, including mine and such account is not added to this key, so it should not be needed.

Need to check other services that depends on it like BFE and IPSec maybe solution is there.

 

 

Just need to find out what knocked down firewall in first place. Thanks for suggestions guys