Daisy-chain Wifi Routers

[NegativeSpace]

I've been helping a friend set up a new home theater system (very badass one, pictures later), and I had to add a router to the theater room. Everything went fine, but there is this one thing that I don't quite understand, which I will get to in a minute.

The network cable that comes from the cable modem is obviously connected to the 'internet' port on the main router in another room. Plugged into one of the LAN ports is a network cable that goes through the house and ends up in the theater. That terminal plugs in to a regular LAN port, instead of the 'internet' port, on the theater room router. The other 3 LAN ports are used for the Logitech Revue, Blu Ray player, and receiver.

I don't understand this one thing; Why is it that the network cable coming form the 'host' router in the other room has to be plugged into a regular LAN port on the 'client' router instead of into the "internet" port? When I went to set this up, I knew that I would need to assign the theater room router an address that is different from the address of the 'host' router. I knew I would have to disable it's DHCP server. I didn't know that the LAN cable coming from the'host' router had to be plugged in to regular LAN port on the theater room router.

Edited April 19, 2012 by NegativeSpace

[Jason Cooper]

I don't understand this one thing; Why is it that the network cable coming form the 'host' router in the other room has to be plugged into a regular LAN port on the 'client' router instead of into the "internet" port? When I went to set this up, I knew that I would need to assign the theater room router an address that is different from the address of the 'host' router. I knew I would have to disable it's DHCP server. I didn't know that the LAN cable coming from the'host' router had to be plugged in to regular LAN port on the theater room router.

It sounds to me like you are using it as a switch rather than a router. Not a problem in this case considering the layout but if you wanted to use it as a router rather than just an additional switch then you would want to disable the NAT on the router and you may need to manually set up the routing tables for it depending on the routers being used.

The reason to disable the NAT on the router is that you don't want to get into the nightmare of multiple levels of NAT where machines at the lower levels can connect to those on the higher level but the higher level machines can't connect to the lower level ones.

Personally unless you have a good reason to really separate the two networks the situation with using the router as a switch sounds fine for the environment.

[redhook]

It sounds to me like you are using it as a switch rather than a router

Yep, I would have just used a switch. If both routers have wireless you could just connect it to the main router in wireless client mode. You will want to disable DHCP on the wireless client router if you do this, that way you bridge them together and all the devices will be on the same subnet.

Edited April 19, 2012 by redhook

[NegativeSpace]

It sounds to me like you are using it as a switch rather than a router. Not a problem in this case considering the layout but if you wanted to use it as a router rather than just an additional switch then you would want to disable the NAT on the router and you may need to manually set up the routing tables for it depending on the routers being used.

The reason to disable the NAT on the router is that you don't want to get into the nightmare of multiple levels of NAT where machines at the lower levels can connect to those on the higher level but the higher level machines can't connect to the lower level ones.

Personally unless you have a good reason to really separate the two networks the situation with using the router as a switch sounds fine for the environment.

So I guess the main difference between a router and a network switch is the ability/use of the things like DHCP server software, NAT (a concept which I have not been able to understand yet), and the other things that routers usually do, but things that this one is not doing. Is that correct?

I had two reasons for using the second router/switch in this case, one being the fact that all 6 main theater devices are networkable and I wanted to be able to network more than just the single one I would have been able to with the single cable. The other reason was the fact that the theaters walls are 24 inch thick solid wood with a steel roof, so the main routers radio signal does not penetrate into the room even though it's only about 20 feet away, and my friends wife likes to use internet on her tablet, which she was unable to do before in this room. The point to all of this being, I had to use the second router for its switch as well as it's radio, so is it still just a switch or.........

While we are on the subject, what are all of the differences between Access Points, Routers, Switches, and Hubs? I, of course, have some ideas of what these thigns mean, but I'm not really the kind of person that is ok with partly understanding anything.

[NegativeSpace]

Yep, I would have just used a switch. If both routers have wireless you could just connect it to the main router in wireless client mode. You will want to disable DHCP on the wireless client router if you do this, that way you bridge them together and all the devices will be on the same subnet.

I had originally planned on using a switch but I found out that the wifi from the main router won't penetrate the 24 inch thick solid wood walls of the theater, so I ended up needing to put a WiFi AP in the theater room for mobile devices.

Is "wireless client mode" an official function of all/most/some routers' operating system software? Or does setting the 'client' router up to not function as a DHCP server, giving it it's own gateway address, and using it's 'switch' LAN ports and not using its 'internet' port, all constitute it being in wireless client mode?

In my OP I actually mentioned the fact that I did disable the client router from being a DHCP server, so does this mean that I bridged the two routers, and that all devices are on the same subnet?

Thanks for replying to my post, but I still don't know why the "internet" port on the back of the 'client' router can't be used for plugging in the network cable that comes from the 'host' router, which was the reason I started the thread.

[Jason Cooper]

While we are on the subject, what are all of the differences between Access Points, Routers, Switches, and Hubs? I, of course, have some ideas of what these thigns mean, but I'm not really the kind of person that is ok with partly understanding anything.

To keep things simple I will avoid talking about level 3 switches, vlans, etc and will just talk about the very basic diffence between the devices.

A wirless access point provides a connection for a number of wireless devices to the network.

A hub shares the connection between all the devices, any packets it receives get sent out on all interfaces (i.e. all cables plugged in)

A switch is smarter than a hub and will look at the packet it has received and send it out to the interface it knows the device is connected to.

The above build up the basis of a network, a router will sit between two or more networks and take the packets passed to it and then depending on the destination network of the packet put it out on a specific network. The difference between the router and a switch is the level they are working on. Routers simply know what network is connected to which interface and switches simply know what devices are connected to each interface.

These are very simplified explanations and things get more complex when you really delve into networks, but hopefully they are good enough to give you rough idea of what each device is doing.

Modern wireless routers are really a switch, router and wireless access point contained in one package. The router part decides if to pass packets to the switch or the internet interface. The switch passes the packet out on the correct interface (one of the cabled ones, the one connected to the wireless access point or the one connected to the router).

[redhook]

Is "wireless client mode" an official function of all/most/some routers' operating system software? Or does setting the 'client' router up to not function as a DHCP server, giving it it's own gateway address, and using it's 'switch' LAN ports and not using its 'internet' port, all constitute it being in wireless client mode?

Many routers have it built in, if they don't you can usually flash DD-WRT.

In my OP I actually mentioned the fact that I did disable the client router from being a DHCP server, so does this mean that I bridged the two routers, and that all devices are on the same subnet?

Yes.

Thanks for replying to my post, but I still don't know why the "internet" port on the back of the 'client' router can't be used for plugging in the network cable that comes from the 'host' router, which was the reason I started the thread.

With a firmware like DD-WRT you can put that port on the same VLAN as the other 4 ports.

[NegativeSpace]

To keep things simple I will avoid talking about level 3 switches, vlans, etc and will just talk about the very basic diffence between the devices.

A wirless access point provides a connection for a number of wireless devices to the network.

A hub shares the connection between all the devices, any packets it receives get sent out on all interfaces (i.e. all cables plugged in)

A switch is smarter than a hub and will look at the packet it has received and send it out to the interface it knows the device is connected to.

The above build up the basis of a network, a router will sit between two or more networks and take the packets passed to it and then depending on the destination network of the packet put it out on a specific network. The difference between the router and a switch is the level they are working on. Routers simply know what network is connected to which interface and switches simply know what devices are connected to each interface.

These are very simplified explanations and things get more complex when you really delve into networks, but hopefully they are good enough to give you rough idea of what each device is doing.

Modern wireless routers are really a switch, router and wireless access point contained in one package. The router part decides if to pass packets to the switch or the internet interface. The switch passes the packet out on the correct interface (one of the cabled ones, the one connected to the wireless access point or the one connected to the router).

Great explanation. I understand perfectly.