Finding a routers setting's page that is getting internet through a local switch

Question

I have a switch that's getting shared internet, I've connected a wireless router to that switch so I can share the connection through WiFi.

AFAIK, the router isn't giving out the IPs and isn't the default gateway.

Is there a way to get the IP address of the router so that I can access the setting's page through a PC connected to that switch?

Note: Using Windows 7 in the Host.

Network Illustration

Answer 1

You need to connect to the router via wired interface from your laptop. The reason is - if you do not have WiFi password you can't connect through WiFi because laptops wireless card first associates with the router's SSID and only then gets IP address.

If on wired interface DHCP not working too, then look for the router's manufacturer's user guide. It will contain method how to reset router to default settings - there the IP will be known.

As per your request - how to discover the router's address once you are on the same subnet as the router. It means that the computer which you are running this from has already joined the router's wifi access point and the wireless adapter IP is set to one belonging to the router's IP subnet. Say the router's IP address is expected to be 192.168.0.1 this means it is on private C class network (see Private Network) where netmask would be 255.255.255.0 or alternatively netmask is written as /24. So you could assign to your laptop's wifi interface any address from 192.168.0.2 to 192.168.0.254 (only the number after the third dot changes).

Then you use NMAP which is available for windows, mac and linux. The command you use is nmap -sn 192.168.0.0/24 - of course you adjust the IP address and netmask for the network to the one that you know your router and laptop are on. You get a list of all active IP addresses in that network (up to 254 for C class) together with their MAC addresses and usually the manufacturer's name. You can then narrow it down pretty quickly which is likely to be your router. Examples of manufacturers off the top of my head are Raspberry Pi Foundation for pis and Arris Group for a VirginMedia router.

As you notice - if you need to both join the router's access point (so that you are on the same wifi infrastructure) and know what the network address is, you are nearly there. If you do not know these things - that is when you may need to get the router's manual in order to factory-reset the router and then get access using the default settings. Again - easier via a cable. And reset usually will auto-enable DHCP server.

As per your illustration - you should be able to connect to the router from your PC using wired connection; it all hinges really as to what IP address the router interface has and what your PC has. If their IP's are on the same subnet - they should see each other. If you want to connect via wifi - you have first to associate with the AP then solve the problem with IP. On the other hand - you have a wifi password so the first should not be a problem. Then the typical network address ranges you can try are: 10.0.0.1 to .255 netmask 255.0.0.0, 192.168.0.1 to .255 netmask 255.255.0.0, 192.168.1.1 to .255 netmask 255.255.255.0, 172.16.0.1 .255 netmask 255.255.0.0 (see also this post). So you would try setting your wifi adapter to 4 different addresses.

By far the easier way to learn address information is by looking at other computers that are successfully joined to the same network (either wifi or wired). On linux ip addr list and ip route show; on Windows you would go to network properties - your network adapter - connection information.