Configuring network with two routers?

michaels

A bit of advice please.

I have an N wireless modem router (O2 IV box) with a USB HD plugged in plus a ethernet cable connection to the uplink port of a second wireless router and one or more PCs by wifi.

The second router is connected to a couple of PCs by cable (one of which hosts all my multimedia) and two others by wifi. None of the PCs is a server and both routers are DHCP servers (with different IP address ranges).

The problem I have is that PCs connected to the second router can see the internet but can not see the network drive attached to the modem router and the PCs connected to the first modem router (by wifi) can see the attached drive but can not see the PCs linked to the second router.

I assume I should have one of the routers configured as a repeater but I don't want to end up with all data transfers going via the modem router (ie both ways on the link between the two routers.

Thanks

Michael

scheming_gypsy

Been a while since i did proper networking so i'm a bit rusty.

If everything on router A can see everything on Router A but not router B and vice versa... Can you ping router B from any devices on router A; if not, what happens when you do a tracert from one to the other?

kwikbreaks

The simplest thing to try would be to connect up to a lan port on the secondary router instead of to the wan port. With any luck that will make it work like a dumb switch + AP so everything will be on the one subnet. You may have to turn off DHCP on the piggy-backed router it it may well just work without doing anything. Of course it may not work at all too but it's simple to try it out.

Bogtrotter

Ok don't know the O2 IV router but obviously its a wireless router with some sort of built in filesharing software. I'm assuming that you can access the USB drive if you connect a computer to the O2 router.

That means that the USB Drive is shared on the O2 router subnet which is different to the subnet of the router where other computers are connecting from. The WAN port probably just passing internet traffic from the second subnet (router 2) through the gateway (O2 router).

A possible quick fix is to leave the settings as they are except change the subnet mask on each router to 255.255.0.0 this may allow you to see devices on the first subnet while connected to the second subnet.

If that doesn't work it means probably changing the settings on the second router to behave like a network switch.

patman99

If you can tell us the make/model of each router (either on sticker underneath, or in 'Firmware' section of router's browser-based control system) then we can advise further.
Neadless to say, as you are using two different IPAddress ranges for each router, they will need to have advanced router settings altered.

Basically, if you have two routers, each with it's own IPA range, each will see the internet, but unless told about the existence of the other network, will not see it. This is your problem.

If you don't really need to run 2 different networks, log in to the second router and switch-off DHCP server, and give the router a static IPA with the last digit being one higher than the O2 router. Routers set-up this way are more than just 'dumb switches + AP'. You can still set router 2 to block certain websites or MAC addresses.

Just changing the subnet to 255.255.0.0 will not work as all this does is to allow more devices to be used on a particular network.

For instance.
Your O2 router IP Address might be -
178.23.6.1
255.255.255.0

This means that you can have 253 devices connected (with IPA's in the range 178.23.6.2 - ...264). By changing the subnet to 255.255.0.0, then each time the final group of numbers reaches '254', then the 3 group increases by '1' and the last group starts back at '1' and so on. So in theory, you could have 248*254=62992 devices connected.

closed

Do you really need this complicated setup?

opening up all the ports on the second router might help

patman99

Giving the 2nd router a fixed IP Address in the range offered by the O2 router, then using the 2nd router elsewhere in the house to act as a wired/wireless gap-filler/range extender.

pcombo

simple,

1 cable into both routers.

i use this config.

router1: 10.0.1.1/255.0.0.0

router2: 10.0.2.1/255.0.0.0

Bogtrotter

Just did a experiment to see what would happen.

First can't replicate completely because I only have basic ADSL routers without WAN uplink connection.

1. Both routers DHCP connected together on different subnets (192.168.0.0 and 192.168.1.0 mask 255.255.255.0) can't access or ping devices on one subnet from the other as expected.

2. Change subnet mask on both routers to 255.255.0.0 can access all devices from either subnet. However second subnet cannot access internet I think because of lack of WAN connection port and/or inability to specify gateway IP address in configuration.

3. Turning off DHCP on the second router (O2 version2) turns it into a simple switch which passes DHCP from the primary and everything works.

So I think it will depend on the routers as to their capabilities but I would stand by my first suggestion and try changing the subnet mask on both routers to 255.255.0.0 and see if it works.

If it doesn't next try switching off DHCP on the second router and connecting to the other router through the normal ethernet port (not WAN connection).

patman99

One thing I found was that depending on who makes the router, they may block routable IPAddresses. This makes it much harder to do what you wish to do.

If you can post a picture of the routers, we might be able to identify the maker and give you more advice.

Based on what you posted about your IPA's, if your Routers have an 'Advanced Routing' option or similar, then you would need to do this -

On the Advanced Routing section of the O2 unit, you would need to enter the IPA of your other router and use a subnet of 255.255.255.0

On the second Router, just repeat but with the IPA of the O2 router.

To understand why changing the subnet caused you problems, you should have a read of THIS article. It is the clearest one I can find on the subject.