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My Windows 7/64 machine has suddenly started to act funny. Everything will be running fine, when suddenly most network access methods will fail. These things continue to work:
- Accessing network mapped drives
- Ping (both intranet and internet)
- DNS for URL resolution
- Skype
These things fail:
- Printing to a local network device
- HTTP (I cannot browse to Internet sites, nor my local router's internal http server)
- NNTP
- IMAP
- POP3
- SMTP
- Telnet
I've tried using ipconfig /release then /renew without success. Rebooting the machine cures the problem, until it happens again (anywhere from 4 to 40 hours later).
Any thoughts or suggestions?
How exactly do these protocols fail? What errors do you get? What security software do you have installed? Do the problems persist if you (temporarily) disable or remove it? – Ansgar Wiechers – 2012-10-07T16:10:23.520
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2To be more specific, this is related to TCP protocol since Ping is ICMP, DNS UDP and skype may use UDP only and still working afaik... – climenole – 2012-10-07T16:27:18.973
1You say: «suddenly»... Check in devmgmt.msc for problematic network device (yellow triangle + err msg). Check also in eventvwr.msc for error or warning msg. If it's recent try a System Restore. – climenole – 2012-10-07T16:44:07.690
@climenole, thanks for that insight regarding the protocols. I'll definitely check those diagnostic tools. System Restore isn't an option, as it's been a couple of weeks since it first started happening, and many things changing on my machine on a regular basis. BTW, I can tell it's "suddenly", because I'll hear the message checking utility beep at me, and I'll discover that everything is wonky. – Mike Hanson – 2012-10-07T17:42:39.707
I've discovered that the mapped network drives actually work, but I'm assuming they're not using the TCP stack. (I've edited the message to reflect this.) – Mike Hanson – 2012-10-22T17:52:02.503
Windows file sharing on recent versions (Vista and later) does use TCP. Specifically it uses NetBIOS over TCP. Older versions of Windows (or any version of Windows connected to a very old server, Windows 2000 or older) would use the "hard" NetBIOS protocol, which indeed, is not TCP. – allquixotic – 2012-10-22T18:34:07.847
My advice is to download and fire up Wireshark and monitor your traffic... during an "outage", observe which protocols are going through and which ones are blocked. This can help you definitively determine if it's just TCP. – allquixotic – 2012-10-22T18:35:16.630
Thanks, alquixotic. I'll download and run that now (while I'm connected <g>). – Mike Hanson – 2012-10-26T09:41:08.080