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They are both pluggen in via Cat5. This problem started yesterday and i have yet to find a solution. They have network access on the domain, however no internet. Occasionally I can make them work with a ipconfig/release than ipconfig/renew. Any ideas?

8 Spice ups
2

I am getting a error "Can not contact DNS server

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Do an ipconfig /all and look at your DNS servers. Do they look correct?

4 Spice ups
4

Is your DNS server in house or you use a third party ? Do they have a static IP address and maybe a device is blocking them from reaching the internet ?

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Also, check for any static DNS entires on your NIC, as well as your wireless adapters if you have those turned on.

3 Spice ups
6

Try ping ip address, then move to the router, then to a website www.google.com . This will help you find out where in the network the error is. If your IP doesn’t include a gateway, but is rather a generic IP address that is added by default, it could be a issue with getting an IP from the DHCP. I would definitely check the DNS settings using ipconfig /all as stated above. I would also try ipconfig /flushdns.

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No it does not. Even when i manually enter the correct DNS server it doesn’t respond

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have tried flushdns with no avail

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Have you checked the hosts file ? Can you ping 8.8.8.8 ?

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10

Are you using a proxy server? If not, make sure the machines are not listing a proxy address.

11

unreachable

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Is your Gateway correct? If you can’t reach your DNS server after manually entering it, your gateway could be the cause.

Also maybe try different ports on the switch.

2 Spice ups
13

Have checked different ports on switch also… Many other devices are plugged in and they test well in the ports also. We had a web filter replaced recently. Could that cause this?

14

have you tried to delete the ARP cache for those devices?

I remember troubleshooting two devices just like this, but I think they were not able to access the domain period. It has been a while, but worth a shot. Might as well throw everything at it including the kitchen sink.

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Have you thrown the laptops up against the wall? Longshot :slight_smile:

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16

system restore. it looks registry is corrupted

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Have you taken the laptop and plugged it directly to the switch port? Is it possible someone changed the VLAN assignments of those ports specifically? Do you have another vacant port on the switch you could try ?

Thinking maybe the switch was rebooted and the running config got wiped, it reverted back to an older startup config and the switch ports / vlan is / are different.

Maybe try that laptop in a known working port, patched directly into the switch.

18

Could be a rogue DHCP server, try ipconfig /all when it works and post the config, do the same for when it fails.

3 Spice ups
19

Have you tried another machine plugged into those drops? It’d be interesting to see if the symptoms follow the drops or the laptops.

Also have you checked your settings in IPconfig/all? Check to make sure they are getting valid addresses, etc.

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That was my first thought. Someone wants wireless, so they bring in a wireless router and plug it into the network. Now it starts handing out DHCP addresses. Your users will randomly get an address from your official DHCP server, or the rogue router. If the address comes from the rogue router, it probably isn’t going to work well on your network!

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