colinc Posted October 20, 2005 Report Share Posted October 20, 2005 Any other network tech's out there got any thoughts about this? 9 PC network (all XP Pro or Win2K) connect to internet via SMC router and cable modem. All IP info comes via DHCP from the router. During the afternoon every day 2 of the PC's cease to be able to connect to the Internet, local connections to server and printers work OK, They get "Page not found" or "unable to find host" when trying to browse or connect to external mail server. Can ping ISP DNS servers and other sites ip addresses but no DNS resolution. ipconfig shows all of the right stuff, I have run virus and spyware scans, no problems found. Checked for duplicate IP addresses. By the next morning it all works OK again!!!! Any thoughts most appreciated as I don't have any hair left to tear out. Thanks Colin Link to comment Share on other sites More sharing options...
Ritey Posted October 20, 2005 Report Share Posted October 20, 2005 Are all machines on, active and using the net at the time this happens? Link to comment Share on other sites More sharing options...
colinc Posted October 20, 2005 Author Report Share Posted October 20, 2005 Yes all machines are on most of the time, certainly no pattern there Link to comment Share on other sites More sharing options...
danksy Posted October 20, 2005 Report Share Posted October 20, 2005 Are the network cables nearby to anything which switches on at the same time of day every day that could create any interference? Are the cables properly shielded? If you plug the "rogue" PC's into different ports on the router does the problem stay with the rogues, or move to the PC you have connected? Link to comment Share on other sites More sharing options...
Frodo Posted October 20, 2005 Report Share Posted October 20, 2005 What is the lease period of IP address? Windows clients will need a successful renew by 86% of the lease time. Can you telnet to remote web servers on port 80? What happens if you flush the DNS cache? Any log info on the router? Link to comment Share on other sites More sharing options...
colinc Posted October 20, 2005 Author Report Share Posted October 20, 2005 [ QUOTE ] Are the network cables nearby to anything which switches on at the same time of day every day that could create any interference? [/ QUOTE ] No, there are 5 PC's within the same location, one "group" of two and one of three with one "rogue" PC in each group [ QUOTE ] Are the cables properly shielded? [/ QUOTE ] All Cat5e [ QUOTE ] If you plug the "rogue" PC's into different ports on the router does the problem stay with the rogues, or move to the PC you have connected? [/ QUOTE ] forgot to mention that the router is a single port device that goes to a 10 port switch Link to comment Share on other sites More sharing options...
colinc Posted October 20, 2005 Author Report Share Posted October 20, 2005 [ QUOTE ] What is the lease period of IP address? Windows clients will need a successful renew by 86% of the lease time. Can you telnet to remote web servers on port 80? What happens if you flush the DNS cache? Any log info on the router? [/ QUOTE ] IP lease is 3days, not tried telnet, not tried DNS flush on local machine but will power off do that anyway? Router is very basic but I'll see if I can find anything log-wise Link to comment Share on other sites More sharing options...
Turrican Posted October 21, 2005 Report Share Posted October 21, 2005 Also with one of the PC's that lose connection try the tracert command to www.yahoo.com or www.bbc.co.uk . You should be able to see how far it's getting. Link to comment Share on other sites More sharing options...
Rachel Posted October 21, 2005 Report Share Posted October 21, 2005 [ QUOTE ] Can ping ISP DNS servers and other sites ip addresses but no DNS resolution [/ QUOTE ] Yuck - If you cannot ping these same machines by their names (eg. serverx.domainy.co.uk) you have a name resolution problem. Horrible thing to sort out. Is it always the same 2 PCs that misbehave? Check their settings for NetBios and WINS vs the other systems would be the first place I'd start. Also - are you only running ONE protocol stack on each PC. By this I mean - is TCP/IP the only protocol you have configured, or do you have NetBEUI or IPX/SPX (or something else?) also configured? Nowdays - you should pretty much only need to run TCP/IP. Link to comment Share on other sites More sharing options...
colinc Posted October 21, 2005 Author Report Share Posted October 21, 2005 [ QUOTE ] Yuck - If you cannot ping these same machines by their names (eg. serverx.domainy.co.uk) you have a name resolution problem. Horrible thing to sort out. Is it always the same 2 PCs that misbehave? [/ QUOTE ] Yup same 2 machines every day [ QUOTE ] Check their settings for NetBios and WINS vs the other systems would be the first place I'd start. [/ QUOTE ] [ QUOTE ] Also - are you only running ONE protocol stack on each PC. By this I mean - is TCP/IP the only protocol you have configured, or do you have NetBEUI or IPX/SPX (or something else?) also configured? Nowdays - you should pretty much only need to run TCP/IP. [/ QUOTE ] TCP/IP only as everything is Win2000 or above Thanks for all of the suggestions, it is the time element of this that is really getting to me, why the hell does it work in the morning but pack up in the afternoon!!! as all of the machines use the same hub, router etc, why only two!! Link to comment Share on other sites More sharing options...
Frodo Posted October 21, 2005 Report Share Posted October 21, 2005 What is the IP address of the machines when they stop working? What happens if you do an ipconfig /release, ipconfig /renew? If you type NSLookup when they work what do you get? What about NSLookup when they stop working? Link to comment Share on other sites More sharing options...
colinc Posted October 24, 2005 Author Report Share Posted October 24, 2005 ipconfig shows 192.168.22.116 & 118, release/renew gets same ip's back along with correct gateway and DNS ip's nslookup resolves OK when working but not when broke. did some more tests on 1 workstation today, it was working OK till about 3PM then stopped, basically the router can be pinged but not connected to via http, all internal network functions are OK, I tried the cable and port from working machine, this does not change the symptoms. the problem is definitely on the workstation, what still bugs me is the time thing. The problem was gone by 16:30 but I do not really know if it was one of the 33 Windows updates or just the time that fixed it for today. I await a call from the user tomorrow!! Link to comment Share on other sites More sharing options...
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