DNS Problems at work...


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Ok here is my situation...

I work at a hotel and we are currently using RoadRunner Business Class 15/2 for our wi-fi network. The primary modem is a Ubee DDW3361 with a cheap Cisco Router thats then connected to a switch... (Horrible Setup) Now I know a fair bit about networking and I know this network is completly FUBAR. There are 4 building on the property each building has 3 routers with the exception of the lobby. Everything seemed to work fine but since last week I cannot get on the internet in the lobby and get nothing but DNS errors and so have several guests. I had nothing to do with this network setup but I am almost 100% certain the the modem is not bridged there for creating a double NAT and it makes it almost impossible to get out to the internet.

I have troublshooted my laptop and everything is fine, I have even tried 2 seperate devices all with the same problem. My boss will not let me touch the network and will not call to have a tech fix the issue. I was wondering if there is something I am possibly overlooking on my end because my boss will not let me touch the routers and fix the problem even though I am pretty certain I can get it fixed. Does anyone have any opinions or ideas on how I can possibly fix this mess without knowing the password for the router? I know there is nothing vital setup on this network as it is a guest wifi network.

Any help in this matter would be greatly appreciated.

Thanks!

PS: I am using my phone as a tether to post this... Pretty sad...

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You say Cisco, could it be this ?

http://www.electroni...lback.possible/

I totally forgot about that but that would make sense. I have no idea if it has been updated or not, I guess I could always reset the router and use the default user id and pw to check it out.

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Update: Router lost its configuration and I had to redo all the static IP addresses and everything is back up and running except for my laptop. I have deleted all networks, tried assigned IP, 3 different wifi adapters and Ethernet but I still can't get online. I am pulling a valid IP but can't ping the modem, I booted to safe mode with networking and the internet works for about 2 minutes then stops. I am at a loss on what to do as nothing is working here at work but I have zero problems at home. My phone connects to wifi no problems.

Please help!

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Scanned for malware ? Checked hosts file, proxy etc ?

I can't get online to download anything that's my problem. I am half tempted to do a fresh install and see what happens but I'm just confused as it works at home no problem.

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Ah sorry, the whole safe mode with networking thing distracted me from the original problem

No problem, I was able get malwarebytes downloaded bandits clean and I've never messed with my host file. Any other ideas I could try short of reinstalling windows? This has to be a issue with my computer as it works when it wants to but my phone has no issues.

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No problem, I was able get malwarebytes downloaded bandits clean and I've never messed with my host file. Any other ideas I could try short of reinstalling windows? This has to be a issue with my computer as it works when it wants to but my phone has no issues.

So connected to the lobby at work, all devices except your laptop connect fine ?

But your laptop connects fine at home ?

You have tried static and dhcp on the laptop, Static having the correct range set with say 8.8.8.8 and 8.8.4.4 for the DNS ?

And the hosts file could have been changed by malware, I had to clean up a laptop not long ago that redirected Google and Yahoo! to a malware IP

Reset IE to default, make sure nothing is hiding in the proxy settings

Along with Cybers suggestion, try this at CMD:

netsh int ip reset c:\resetlog.txt

netsh winsock reset

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Yup no problems at home. When I run a diagnostic on the network adapter here is my error http://db.tt/nMvpbpMY

I have tried several different static ips and Google DNS and open DNS with no luck. (Network adapter).

I have also gone into msconfig and selected normal startup so all services are enabled and still no luck. And yes the hosts file is clean.

Edit: Tried the commands, still no luck.

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I am pulling a valid IP but can't ping the modem,

If you have the modem and router on the same LAN, both may have DHCP enabled. A bit of a lucky dip which one will give you an IP address, but if the router gives it to your laptop before the modem, then it is probably going to give you an incorrect default gateway of the router (which has an empty WAN port) instead of the modem (which is actually doing the routing in this case). Make sure you do ipconfig/all to check the IP addresses and make sure that they really are right, and turn off DHCP on the router if you already have DHCP on the modem.

Also I have seen some pretty dodgy D-link routers completely elsewhere in the network that give out dodgy DHCP even if DHCP is set to "off" or "access point only" and need the firmware to be updated to fix this problem.

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If you have the modem and router on the same LAN, both may have DHCP enabled. A bit of a lucky dip which one will give you an IP address, but if the router gives it to your laptop before the modem, then it is probably going to give you an incorrect default gateway of the router (which has an empty WAN port) instead of the modem (which is actually doing the routing in this case). Make sure you do ipconfig/all to check the IP addresses and make sure that they really are right, and turn off DHCP on the router if you already have DHCP on the modem.

Also I have seen some pretty dodgy D-link routers completely elsewhere in the network that give out dodgy DHCP even if DHCP is set to "off" or "access point only" and need the firmware to be updated to fix this problem.

Static IP would solve that problem though

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Sounds like the static routes are screwed up to me. If you can't route to your internal DNS the name resolution will fail; if you can't route to the gateway, external access will fail along with google DNS. One of the hops between routers is probably misconfigured...

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Sounds like the static routes are screwed up to me. If you can't route to your internal DNS the name resolution will fail; if you can't route to the gateway, external access will fail along with google DNS. One of the hops between routers is probably misconfigured...

It's only the laptop that can't connect, other devices connect fine to the same AP

By chance could an identical computer name cause a conflict, or by 1 in a million chance, an identical MAC address to another on the network?

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Cannot ping anything and I don't have access to the modem and he won't give me access. The Cisco router is configured with a static IP and is set to allow 250 connections starting at 192.168.1.2 with the gateway set to 192.168.1.1. Here is a pic of my screen with all the info and everything shows I should be surfing but can't. http://db.tt/5zfBGIVw

I have also changed my laptop name and workgroup.

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Cannot ping anything and I don't have access to the modem and he won't give me access. The Cisco router is configured with a static IP and is set to allow 250 connections starting at 192.168.1.2 with the gateway set to 192.168.1.1. Here is a pic of my screen with all the info and everything shows I should be surfing but can't. http://db.tt/5zfBGIVw

I have also changed my laptop name and workgroup.

Doubt this would do anything if the account is already an Admin account, but try creating a new user account on the laptop ?

Another CMD

ipconfig /flushdns

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Doubt this would do anything if the account is already an Admin account, but try creating a new user account on the laptop ?

Another CMD

ipconfig /flushdns

Tried both, no luck. Here are the router settings with the ips blocked http://db.tt/TlHImK8v

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Tried both, no luck. Here are the router settings with the ips blocked http://db.tt/TlHImK8v

EDIT - My bad, was looking at the external IP

You say you can't even ping that AP in the screenshot @ 192.168.1.1 ?

What if you tracert 192.168.1.1

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EDIT - My bad, was looking at the external IP

You say you can't even ping that AP in the screenshot @ 192.168.1.1 ?

What if you tracert 192.168.1.1

Tracert worked and it shows I have internet access but as soon as I open a browser I get the DNS error then says no internet access again. Its really intermittent when it happens. By the way I just connected my touch pad for the first time to this network with no problems either. Oh and I have cleared my cache, cookies, and DNS same results.

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Tracert worked and it shows I have internet access but as soon as I open a browser I get the DNS error then says no internet access again. Its really intermittent when it happens. By the way I just connected my touch pad for the first time to this network with no problems either. Oh and I have cleared my cache, cookies, and DNS same results.

I've about exhausted my basic networking troubleshooting skills I think, sounds screwy that the router works with everything but your laptop, yet your laptop works with anything but that router

Has it ever worked with that router ?

Have you made sure there are no static IPs set for the other adapters in that machine like the Ethernet ?

Off to bed now, good luck, hope you get it sorted

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I've about exhausted my basic networking troubleshooting skills I think, sounds screwy that the router works with everything but your laptop, yet your laptop works with anything but that router

Has it ever worked with that router ?

Have you made sure there are no static IPs set for the other adapters in that machine like the Ethernet ?

Off to bed now, good luck, hope you get it sorted

Worked great up until this past Tuesday with no problems. I greatly appreciate your help tonight. Hopefully I will get it figured out. Seems like something is corrupted somewhere I just don't know what. I have tried everything I know and my touch pad and evo 3d work no problems and I have not had a guest complaint today either... If anyone else has any other ideas I am all ears :-)

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Worked great up until this past Tuesday with no problems. I greatly appreciate your help tonight. Hopefully I will get it figured out. Seems like something is corrupted somewhere I just don't know what. I have tried everything I know and my touch pad and evo 3d work no problems and I have not had a guest complaint today either... If anyone else has any other ideas I am all ears :-)

I wish I had more networking know-how :)

Pretty sure Budman will chime in and make us all look like amateurs :p

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