Strange Ethernet/Wireless problem

bluesky74656

bluesky74656

Line Up and Wait
Joined
Dec 31, 2005
Messages
746
Location
Brecksville, OH
Display Name
Display name:
Todd Kooser
So, I'm spending this semester studying abroad in Italy with 19 other people.
One of the apartments has an ethernet connection, but it's a bit strange. The plug on the wall has an electric line that needs to be plugged in for it to work. As long as everything is plugged in, the system works as expected.

Until I tried to hook up a wireless router, that is. While any computer connected to the wall gets an IP address via DHCP just fine, the wireless router does not. I've tried the router in both gateway and router mode, both to no avail. Giving the router a static IP in the same addressing scheme doesn't work either.

I'm beginning to think that there's something different in the way this network works that isn't letting me use a router. Does anyone have any experience with this sort of thing?
 
Can you turn on detailed logs in the router and see what it says? Maybe you can get a clue from it. Can you upload a picture of this "ethernet plug that has an electric line that needs to be plugged in"? I'm not following that.
 
It's quite possible that the ISP has set up the upstream provisioning device to look for a specific MAC address, so that only the original PC will work. Most routers have the capability to clone the MAC address from an inside PC. So... try that.
 
TMetzinger said:
It's quite possible that the ISP has set up the upstream provisioning device to look for a specific MAC address, so that only the original PC will work. Most routers have the capability to clone the MAC address from an inside PC. So... try that.
Click to expand...

Yeah, I thought of that too, til I read that "any computer plugged into the wall gets an IP from DHCP". Of course, "any computer" might be ones that the school knows about.
 
It's possible that you may need to plug it in because they are actually doing Ethernet over the power line. Or you might just have to plug it in because there's some sort of switch in the wall to boost the Ethernet signal.

On a Windows laptop hooked up to the wall (not through the router) do the following:
1.) Click Start
2.) Click Run
3.) Type in cmd
4.) Click OK
5.) Type in: ipconfig /all
6.) Copy and paste the output as a reply to this thread.
 
I have the feeling there's more to the troubleshootign than what you're doing.

Do the ipconfig as Jesse says and WRITE DOWN the default router and DNS servers addresses.

When you hook up the gateway and try giving it the same IP address, you also have to give it the default gateway IP address. Then Ping FROM the router to the IP address of the default gateway (not from a PC inside....yet. There will be a diagnostics section on the web interface on the router.) If that works, ping the addresses of the DNS servers, that works, you can set the DNS server addresses, and then ping www.yahoo.com. If all is working, try using a PC on the router's network.

Do the same troubleshooting on the PC. Ping the wireless gateway, ping the DNS server, set DNS server addresses, ping yahoo by name. If those work so will your browser.

As Jesse says tell us far those tests get you and which fail if any.
 
Last edited:
Thanks guys. It's 2 in the morning now here, I'll try the stuff tomorrow. I also realized that both the signal from the wall and the router are using the same addressing scheme (192.168.1.x), so I'll try changing that on the router as well.

When I tried the static IP I was specifying the gateway, but I assumed the DNS server was the same as the gateway. I'll check using ipconfig tomorrow.

The school definitely hasn't seen these computers, they're all personal laptops, and this is an apartment.
 
bluesky74656 said:
Thanks guys. It's 2 in the morning now here, I'll try the stuff tomorrow. I also realized that both the signal from the wall and the router are using the same addressing scheme (192.168.1.x), so I'll try changing that on the router as well.
Click to expand...

Be sure you plug the ethernet cable from the isp into the upstream port on your router. Be sure the router is in default configuration, most have a tiny reset button somewhere.

You could try turning dynamic addressing off on the router and just let the ISP's router assign address to the wifi clients.

Another technique that would work is to put a second NIC into one of the PCs and use internet connection sharing. In this case you would set the nic connected to the isp to sharing, and plug the upstream port of the router into the second nic. Since ICS assigns addresses it would be best to turn off dynamic addressing in your router.
 
How about some basics...
Are you getting a link light on the router?
Have you tried a crossover cable?
If you're getting IPs from a DHCP source, why not just use a switch and not a router? I'm presuming you're using a wireless access point/router/4-port switch kinda thing. Plug it into the switch side, disable the router and now you've got a wireless access point with a few extra 100base ports.

More thoughts:
My broadband connection here only has a 10base connection, and it always gave me trouble with various 100base cards/routers. I had to manually fiddle with the speed and duplex settings to make it work. I'd get a link light, but no IP.
 
Last edited:
If the DHCP server in the wall is giving you an ip in the 192.168.x.x range, you're router isn't going to work. The WAN port on your router expects to see a WAN connection not a LAN connection. You could probably use your router as a switch by connecting from the wall to one of the switch (LAN) ports instead of the WAN port. This will probably work if you just want to share the single net connection with a few other wired computers. However you might run into problems if you want to connect to the router wirelessly in this configuration.
 
Joe Gremlin said:
If the DHCP server in the wall is giving you an ip in the 192.168.x.x range, you're router isn't going to work. The WAN port on your router expects to see a WAN connection not a LAN connection. You could probably use your router as a switch by connecting from the wall to one of the switch (LAN) ports instead of the WAN port. This will probably work if you just want to share the single net connection with a few other wired computers. However you might run into problems if you want to connect to the router wirelessly in this configuration.
Click to expand...

That could mean that they have a local router in the building. Anyway, his router might even work with the 192.168. networks on both sides, but if not he can configure the inside network to be 10.x.x.x and have it hand out addresses in that range by DHCP. He did say he tried a bridged mode.
 
mikea said:
That could mean that they have a local router in the building. Anyway, his router might even work with the 192.168. networks on both sides, but if not he can configure the inside network to be 10.x.x.x and have it hand out addresses in that range by DHCP. He did say he tried a bridged mode.
Click to expand...

But why even have another router in the mix? Just plug a wireless access point in or just another switch?
 
Joe Gremlin said:
If the DHCP server in the wall is giving you an ip in the 192.168.x.x range, you're router isn't going to work.
Click to expand...

Not quite.

The important thing is that his NAT router's LAN is not in the same subnet as the WAN side. Given that his netmask is most likely 255.255.255.0 his subnet is going to be something like 192.168.1.0/24. So technically the WAN side could be something like 192.168.0.0/24...or 192.168.2.0/24...or 10.10.10.0/24..Or you get the point. Just something in a different subnet.

Example:
His Router:
WAN Subnet: 192.168.0.0/24
WAN IP (dhcp'd by their router): 192.168.0.100/24
WAN Gateway (dhcp'd by their router): 192.168.0.1
LAN Subnet: 192.168.1.0/24
LAN IP: 192.168.1.1

His Computer:
IP: 192.168.1.2
Gateway: 192.168.1.1

If his computer sends data to an IP address outside of his subnet (anything outside of 192.168.1.1-192.168.1.254) it will send it to his gateway which is his router. His router will send it to it's gateway which is their router. It will continue to route throughout the internet until it arrives at it's final destination.

The most important thing with this stuff is understanding what a subnet is. Once you properly understand a subnet and learn the implications it has on DHCP, and the purpose of a gateway. This stuff becomes very simple.

Until he posts some basic information as I requested above. Any attempt at troubleshooting is pointless.
 
Last edited:
Eh, sorry I didn't get back here sooner. It's amazing how just trying to explain the problem to someone else helps get it clear in your own head. The first thing I did was change the router to a 10.x.x.x addressing scheme and it worked fine.
 
You must log in or register to reply here.
Back
Top