Internet Stops Working

[LiquidVirus]

Hi my name is Robert

I do after hours support work for clients here in South Africa. Recently my one client wanted to buy a new ADSL router, cause their current one wants to be restarted like at least once a day. So i bought them a Dlink DSL 504T.

Here is the setup they have. Currently they have their old Netgear router, which is functions as there DHCP server. This router has two desktop PC connect to it directly using normal ethernet. It also has a Gigabyte wireless access point connected to it. The Access point provides the connection for their 3 laptops. Everything works fine with this setup, except for the fact that they have to restart the router once a day, cause some how it loses the internet connection.

So i bought the Dlink DSL 504T, put in all their ADSL setting, changed the IP and DHCP setting on it, so that every thing is exactly the same as it was on the old Netgear. Everything works 100% everyone can connect except the one laptop it is a Gigabyte N501, stop the internet from working, the network is still working fine, and accourding to the router the inter in still connected, but it just stops the internet on every computer, everyone get a page cannot be displayed message. When that laptop is in range or switched on the internet dies. If I switch it (the laptop) off, and just restart the router everything is fine.

What could possibly be the reason, as the laptop works fine with their old router and I have tested the laptop at another site where it also works fine. The laptop has Norton Internet security on it, and I thought that in some way that cause the problem, so I unistalled it, but still no change. I have switched windows firewall off aswell, but no change.

I am all out of ideas, what could be the problem, like I said, it works fine when I have their old Netgear router pluged it, but as soon as I plug the Dlink in and switch that laptop on, the internet stops.

I need help Dessprately.
Thanks in advance
Robert

 

[CITech]

Hi Robert

Sumarising the problem, things only start playing up when that one laptop comes near the network?

At a guess I would say that the laptop is causing a conflict (obvious comment ha ha), and I would guess it is in the network addressing area. There may be a chance that the laptop is trying to utilise the same IP address as the network router, hence other traffic remains OK until they try to connect to the internet IP. Can you see whether there is a lot more traffic across the SWITCH side of the router when the laptop tries to connect?

Is the laptop using DHCP or static IP? Try putting it on an alternative address, and make sure that there are no additional IP's in use of the laptop. Also, does the router have a second address by any chance?

The hidden addresses may not be immediately evident so have a dig around and see what you can find.

Good luck.

 

[LiquidVirus]

The Laptop gets its IP address automatically. The Routers has two IP's one that it has on the netword and one that the ISP automatically assings to the ADSL Modem part, this one changes as it is not static. The Router's netowrk IP address is 192.168.0.1. The DHCP on the router only starts sending out adress from 192.168.0.2 and on.

I have checked and no computer has the same IP as the laptop, i have aslo put a static address in that range on the laptop but no change. I also put the MAC address on the router so that it assigns a specific address to the laptop. The Laptop gets this address, but still no change it keeps killing the internet for everyone.

 

[CITech]

The Laptop gets its IP address automatically. The Routers has two IP's one that it has on the netword and one that the ISP automatically assings to the ADSL Modem part, this one changes as it is not static. The Router's netowrk IP address is 192.168.0.1. The DHCP on the router only starts sending out adress from 192.168.0.2 and on.

I have checked and no computer has the same IP as the laptop, i have aslo put a static address in that range on the laptop but no change. I also put the MAC address on the router so that it assigns a specific address to the laptop. The Laptop gets this address, but still no change it keeps killing the internet for everyone.

OK, so the laptop IP is driven by it's MAC address? I don't think the problem has anything to do with the MAC but I will keep it in mind.

If you use an alternative switch/hub, does the laptop connect up and run OK? I know you said it works OK on a different network, but I am only interested in the problematic one at the moment.

If you get the chance to try this, can you then try "pinging" the IP address of the router (even though I know it has been switched off)?

If there is an address conflict it doesn't sound to me that any of the other machines are at fault (assuming that they continue to run even once the elaptop is linked up) so at this stage I think we can discount that area of the network.

Let me know how you get on and I will have another think about it.

Cheers

 

[LiquidVirus]

I only tried using the MAC address, to see if that maybe helps with the problem but it didnt change anything.

If I have everything plugin and the latop connected, i can ping and access every computer. It just stops all the computers from having access to the internet, thus the network side all works fine, its just the internet that it is killing or stopping or something.

The router have 4 build in ethernet ports thus it functions as the normal switch as well. The old router was the same meaning also 4 ethernet ports. If i connect the old router now, thus removing the new DLink one, everything works 100% network and internet, on every computer in cluding that laptop.

The reason why they wanted a new router was because the old wants to be reset about once a day (i thinks its memory fills up, thus just wants to be cleard) They dont wanna go and switch it on and off every day anymore, so thet got the new one.

Thanks for all the help thus far.

 

[CITech]

I hear what your saying Liquid, but I'm still working around the idea that there is a rogue IP address in there somewhere. Unless you are routing all your internet traffic via the laptop I can't see why adding that machine to the network would cause you grief.

What I was asking in my last post was an attempt to see whether there might be a duplicate "rogue" IP address on the laptop which is causing the conflict.

I accept it's no guarantee, but its one of those things which should be ruled out first.

That's why I suggested removing the router (temporarily) and then trying to ping the routers IP address. If you get a reply it would suggest that there is a dupe address. You would obviously have to test this on a switch which does not have / need and IP, as otherwise you could be transferring the problem!

One other thought, it there any chance that the laptop is grabbing the DEFAULT GATEWAY address, and thus taking it upon itself to try to route internet traffic, but then not having a route out of the problem? Just a thought

 

[LiquidVirus]

I am going to the client this afternoon, and will try and unplug the router and the ping it.

Will also check on the Defualt gateway, but i doubt it, as that laptop usually gets like 192.168.0.4 or 192.168.0.5.

But i will check this afternoon will also try and assign a static address to it and add the default gateway address in there aswell, where i usually just added the IP and subnet.

Thanks alot, hope it works.

 

[LiquidVirus]

Hi CITech

Sorry i didnt respond yesterday, had a bit of a hetic day.

Okay so i went and checked. I connected the laptop using a normal ethernet cable directly to the router (just incase the wireless had somethign to do with it). Nothing else just the router with the ADSL connection and the laptop connected to each other. Still nothing, the moment i connect it, its gets the first address in the range from the DHCP, which is then 192.168.0.2. The internet is still dead. I turned the the router off and tried to ping it, which is also be the defualt gatway 192.168.0.1. just got a destination unreachable message. when i switch the router on, i get a reply, like I should.

Any onther ideas that i could try?

 

[kunal256]

I Believe you should just try and reload windows back on the laptop...just start afresh..and take it from then

 

[LiquidVirus]

Thx for the suggestion, but I cant just reload the computer, as its not mine, its a clients and they use it everyday. I probably have no other option, but will use this as last resort.

 

[kunal256]

Best of luck

Ya when things just get complicated its the best thing to do!! oviously if datz an option!!! BEST OF LUCK

 

[LiquidVirus]

Does anyone have any other options for me to try, rather that reinstalling?

 

[muckshifter]

I haven't seen the answer ... so I'll ask the question.

Is the Laptop using XP Home or Pro ... ?

 

[LiquidVirus]

Pro, Service pack 2