Q&A for How to Connect Two Routers

Yes, see Method 2, Step 1.

If it is a LAN to WAN connection, then they cannot see each other unless you have a VPN setup.

That the modem houses the primary router makes no difference to the instructions given in the article, and the 5GHz band(s) do not overlap with the 2.4GHz band.

Yes. You can disable WiFi on your main router and enable it only on your second router.

It's not clear from your question if you want to set up a VPN client or a VPN server. OpenVPN is probably the answer to either question, though. If you're looking to connect to a commercial VPN service to gain anonymity, then the service provider will have to answer your question. If you intend to set up a server so you can remotely access your main computer, OpenVPN will do anything you need -- it's free and a fully-featured, enterprise-grade solution. To set it up, you'll need to open port 1194 UDP on your router and point it at your server.

The MAC address it wants is the MAC address of the base station, the router connected directly to the modem. You need to make sure your computer is directly connected to the base station, not one of the satellites and access the base stations config page (at 192.168.1.1 or 192.168.1.0 usually). The MAC will be found under either the Information Tab (usually) or sometimes under Router Settings. It will be in hexadecimal numbers 0-f and will look something like this: xx:xx:xx:xx:xx:xx.

Use a mobile device to check for congestion on whichever channel you have it set to (article recommends channel 11). Another distinct possibility is bug-ridden firmware on your router. To remedy that, check for updated firmware from the manufacturer's website. Upload the latest firmware available onto your router, even if it's the same version already on there.

You need two modems, as well as two routers. And you will most likely have to pay for all of them.

It's a complicated task but yes it can be done. Assuming your router supports running a VPN Client and you have a paid or self-hosted VPN Server. All you have to do is login to your router's configuration pages and connect your Router to their WiFi network. Assuming you have your VPN connection pre-configured your router will automatically tunnel all your network traffic via your VPN Server. Your devices may be required to connect via wired medium to your router.

Use the LAN side IP address of the upstream router. This will be 192.168.1.1 in the article's case. However, you could leave the default DHCP setting, and personally, I'd advise that. If it's important to have a specific IP address on router two, use DHCP Leases/Reservations on the first router.

No, the connection is on the first router's WiFi, but if you can get a cable between the two routers, the connection will be a bit faster.

Contrary to an earlier answer, providing the same SSID to multiple APs will not automatically allow computer client devices to switch to the strongest signal as needed (Android devices - there may be others, too - reportedly have "roaming" settings that may auto-connect to stronger signals, however). There is additional hardware available that makes this possible, but is seldom seen in residential / small commercial settings due to cost. Making a switch the way you're doing it is one way, but providing unique SSIDs for each AP gives you control over which AP you connect to and might be a better choice.

In LAN to WAN connections, Router #2 has a WAN IP address that is in the same subnet as the main router's range of 192.168.1.2 to 254 (192.168.1.51 in the example), and a LAN IP address 192.168.2.1. The LAN addresses provided by router #2's DHCP controller are all in the LAN subnet 192.168.2.2-254. When you you need to access #2 router's setup page from a device connected to router #2, you enter 192.168.2.1 in the browser. If you're connected to the main router and need to access the router #2's setup page, you'd enter 192.168.1.51 to get to that same place. Router #2 setup page is accessible from two different directions -- the WAN (192.168.1.1) and the LAN side (192.168.2.1).

If there is an ethernet cable between the two routers, up to 100m should be possible.

Yes.

You need a straight cable, not a crossover cable. Crossover is used to connect two PCs directly together.

Yes, the secondary router must be connected to the main router.

You should instead look at using a DVR for CCTV with a remote viewing option. They usually offer a mobile phone app for viewing as well.

Follow the steps that are listed in the article above.

You will need to connect to the IP address of each router(s), one at a time, from a device on the same subnet. (You can't connect to the 192.168.1.1 router if the device you're using has a 192.168.2.x address.) If you can't access the login page on 192.168.1.1, try 192.168.2.1 (or one of the addresses you specified for the router above). Provide the manufacturer's default username / password combination (if you didn't change it) and navigate to the WiFi settings to select and change the WPA encryption key. (Consider not broadcasting and changing the SSID of your WiFi, too.) Save your changes and navigate to the Administration page to change the default Login username / password. Save your changes again.

Follow the instructions listed in the article above.

The subnet masks do need to be the same on a LAN-to-LAN network. For a home network, a subnet mask of 255.255.255.0 is advisable.

No, you cannot, for a couple of reasons. First, telephone jacks -- while they may look the same at first glance as network jacks -- are in fact four conductor (two twisted pairs) types and will not accept the larger eight conductor (four twisted pairs) connectors used on standard ethernet networking cables. Second, the cable used for telephones lacks the number of twists that are purposely made in the four cable pairs of CAT5. CAT5E, CAT6 (and higher) type cables that are required to reduce/cancel interference and crosstalk. Primarily, it is this lack of twists that severely limits the speed of data transmission. If your locations are close enough, you may have better luck creating a wireless bridge instead.

Most residential routers with stock firmware support VPN servers, not clients (which is what most people are looking for). In order to make your router a VPN client, you'll need to change the firmware to DD-WRT or Tomato or other that provides this function. The most secure client connection is provided by Open VPN and is highly recommended! You must contact your VPN supplier to obtain your account-specific information to be entered in the VPN Client section of the router with DD-WRT / Tomato firmware.

It is not recommended to try to use one router for two buildings, because the internet connection will be very slow for everyone that is trying to use it.

Use a PCI card or USB WiFi network adapter. Either adapter can be purchased online or from your local electronics dealer/superstore. The card is more reliable and powerful, but it will have to be installed internally.

Yes, you can connect your devices with an Ethernet cable to the second router. As the primary router is operating as normal, it can use WiFi repeaters. The secondary router manages its own WiFi, so it should work with WiFi repeaters.

Use a range extender to do this. It can be configured once and there will be no need for any wired connection.

There is no "best" type. LAN to LAN and LAN to WAN describe two different network topologies. Which one to use depends on what you need to achieve. LAN to LAN means that effectively you have one router = one network. LAN to WAN creates two separate networks as you have two active routers, each taking care of its own network.

For LAN to WAN, you have to change your first router IP address, for example from 192.168.1.1 to 192.168.0.1, and that's the router that you want to connect the cable to WAN port.