Strange network issue

[metguru]

I've been having issues recently with my internal network, and I'll attempt to give as much information as possible. The issue is my internet connection (roughly); I continue to lose the ability to load webpages, but its seemingly random, as the connection will come back with time. I'm using windows XP currently, and the adapter says connected, although sometimes pages online will not load. The strange thing is, I have another computer connected to the same switch (connected to the same router), and the other computer works just fine. Which would normally lead me to believe that it is the computer that is to blame, but I have another computer running linux that is connected directly to the router that seems to work intermittently, but has issues (seemingly) at the same time as my XP machine. Now it could just be coincidental, but I can't seem to come to any specific conclusion as to why it is occurring. Another strange issue is when I try doing the repair connection on the XP machine it fails at clearing the DNS cache. This made me try using IP addresses instead of domain names, which did not work either. I simply cannot figure out what is causing this.

[metguru]

It seems like it could be an issue with the DNS client service, which I needed to restart. But that doesn't necessarily solve the problem, as for some reason the service is having issues starting and stopping.

[wiskic10_4]

Wired or wireless?

When you have connection issues, what happens if you release and then renew the IP on either machine? Can you ping Google from either machine?

[metguru]

It seems as though I can ping google, but pages will not load. All my computers are wired. Releasing and renewing seems like it might be doing something, as usually google's home page will load after the connection is reestablished, but then not much will work after that. But actually, instead of renewing the IP I've been disabling and re-enabling the device, as I believe that does renew the IP.

[morganlefay]

ipconfig /flushdns

Try that on the xp machine.

Also maybe try and lower the MTU settings on the router

http://www.butterscotch.com/tutorial...e-MTU-Settings

MLF

[brokencrow]

Try an alternative DNS server. Level3 has public DNS servers at:

4.2.2.1
4.2.2.2

Google's are at:

8.8.8.8
8.8.4.4

OpenDNS:

208.67.222.222
208.67.220.220

Any of those should be reliable.

[metguru]

I flushed the DNS, lowered the MTU to 1000 from 1500, and set my DNS servers to OpenDNS, and I am still having the same issue. Any other ideas?

[brokencrow]

Hardware? Got an extra NIC around?

Could it be an ISP issue? Are you dropping packets?

I often run continuous pings against www.yahoo.com, sometimes for
days at a time, to gauge packet loss. You could run a continuous ping
against www.google.com too.

Trying to gauge packet loss is one of the first things I do on a troubled
network

ping -t www.yahoo.com

[brokencrow]

Also, what are you running for a gateway? I've had recent problems on a
free wifi network I admin when I set udp filtering a little too low and the users
were unable to connect to a DNS server. Oops.

[metguru]

I'm using a netgear FVS318 as my router. I haven't pinged google for long periods of time, but every time I had issues with pages loading I got 0% packet loss (with only 4 pings, as thats the default in xp), but I will try a continual ping and get back to you.