dns timeouts

[Greg]

Ive got a very wierd problem today, i cannot connect to most sites online with my 2 Vista computers, but i can connect with my old XP computer.

I can connect to a few sites, but cannot connect to most, such as microsoft, google, yahoo, this site...but can connect to all of them with this old XP computer.

I've rebooted router and modem
I've flushed dns on Vista machines
I've restarted computers
I've turned off firewall
I've rechecked router settings

I can't figure this out!

I hope someone can help!

[Greg]

On my XP, i added a user "Greg" to it, and when logged in as "Greg" (limited account) or even as "Admin" (Administrator Account) i cannot reach any websites, but then i log in as the old user "Karen" on my old XP i can reach this site and others.

So now i can't reach sites on my newer Vistas, and even newly crerated accounts on my old XP.

If i know the IP number of a site i can reach it, but not with the domain.

[AJ]

Could you have an infection on the network? Is your AV software installed and current on all machines? I'd update and run full system scans. If you have not run spyware scans I'd do that too. I suggest Spybot Search & Destroy from safer-networking.org.

Also check your HOSTS files and make sure there are no rogue entries there. I can never remember the path to the hosts file so just search for "hosts" on the system.

[Greg]

The search function can't find "hosts" and "HOSTS" file...i had it set to look everywhere including system files

I run Norton AV and MS Defender everyday

[m2]

For XP, the hosts file is usually in
C:\WINDOWS\system32\DRIVERS\ETC\hosts

Typically, the only entry, unless you need overrides to DNS is

127.0.0.1 localhost

If you see other entries and want to test removing them, you can comment them out with a hash in the first position, e.g.

# this is a comment

m2

[Greg]

I see an error in my Windows error logs that my PC was unable to renew it's IP address, looks like a DHCP problem on router?

Anything bad happen if i log into router and force a release of current DHCP data and then retrieve new data?

[Greg]

For XP, the hosts file is usually in
C:\WINDOWS\system32\DRIVERS\ETC\hosts

Typically, the only entry, unless you need overrides to DNS is

127.0.0.1 localhost

If you see other entries and want to test removing them, you can comment them out with a hash in the first position, e.g.

# this is a comment

m2

Thank you, it looks fine:


# Copyright (c) 1993-1999 Microsoft Corp.
#
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
#
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# space.
#
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
#
# For example:
#
# 102.54.94.97 rhino.acme.com # source server
# 38.25.63.10 x.acme.com # x client host

127.0.0.1 localhost

[m2]

to renew your PC's DHCP IP address, from the command line:

Code: Select all

ipconfig /renew

If you need a new public IP, reboot your router

[AJ]

Clearing the DHCP database on the router shouldn't cause any issues, but you'll need to renew the IPs on all the computers attached to it afterwards using the command M2 noted or by rebooting them.

are your computers using the router IP for DNS or your ISP DNS addresses? You could also try setting static addresses instead of using DHCP.

I would not trust that Norton and Defender have you spyware free, either. Spybot from safer-networking.org and Ad-Aware from lavasoft.com are two very good spyware scans and they are both free.

[Greg]

Clearing the DHCP database on the router shouldn't cause any issues, but you'll need to renew the IPs on all the computers attached to it afterwards using the command M2 noted or by rebooting them.

are your computers using the router IP for DNS or your ISP DNS addresses? You could also try setting static addresses instead of using DHCP.

I would not trust that Norton and Defender have you spyware free, either. Spybot from safer-networking.org and Ad-Aware from lavasoft.com are two very good spyware scans and they are both free.

The PC's are using the routers IP's which are private IP's.

I've wanted to setup static, but don't get enough public IP's from ISP, and not quite sure about private IP's and subnets to create my own manually with confidence.

I also have xbox 360 in network, so not sure how i would set up static IP there, and it shares a switch with other PC before the router.

I have PC's and xbox into switches, then switches go to router.

[AJ]

I meant static private IPs on the computers, not public. They would use the same addresses as your router is currently handing out which is probably 192.168.0.x or 192.168.1.x and the router address which would be the gateway on the computers would be 192.168.0.1 or 192.168.1.1. When you look at your router settings you'll see what addresses it's using. I just suggested that as a test though to see if it would work that way.

Also in the router settings you should be able to see the DNS addresses that your ISP is using and you could then put those addresses manually in your computer IP settings instead of using the router's address. This frequently fixes DNS issues in small networks with inexpensive routers. It's really just a work around, but better than spending a day messing with it or hundreds of dollars on an IT pro to fix it for you. I'd be glad to put you on the schedule though...might kind of an expensive trip charge.

[Greg]

geez, i haven't done anything or changed settings since the last post, but now i can reach the sites with my main PC. I love these "sometimes it works and sometimes it doesn't" problems...arg

Thank you very much for all your help everyone, i really appreciate it as always...it's great to have people i can ask when i get into problems