Networking: How to add another router

[Michael Tewner]

On Sun, Feb 13, 2011 at 9:28 PM, Michael Tewner <tewner at gmail.com> wrote:

> Hi -
> Shimi's solution will work - use a cross-over cable, though, in order to
> connect the switches together.
>
> Hypothetically, you should be able to connect multiple computers to the
> same network cable - that is, wire 2 connectors, in series, at one end. This
> would give you a "hub" on that segment, and the network cards should manage
> the collisions themselves. I wouldn't recommend this, though, and I present
> it strictly as a thought experiment.
>
> -Mike
>
> (although, the 2 computers on the same cable probably won't be able to talk
to each other :-) )

>
> 2011/2/13 shimi <linux-il at shimi.net>
>
>>
>> On Sun, Feb 13, 2011 at 6:47 PM, Geoff Shang <geoff at quitelikely.com>wrote:
>>
>>> Hi,
>>>
>>> I find myself with the need to connect 5 ethernet devices to 4 available
>>> ports.
>>>
>>> I'm running an ADSL modem/router with a 192.168.2.x network (for
>>> historical reasons) and have allocated static addresses to all of the static
>>> devices, and a pool of DHCP addresses for devices which ask for it.
>>>
>>> Right now the fifth device is running on wireless but I want to plug it
>>> in if I can.
>>>
>>> A quick Google tells me that there's no kind of double adaptor available
>>> to help solve my problem.  The closest I've seen is a way to send two 10/100
>>> mbps Ethernet feeds down the one ethernet cable, but you still need two
>>> ports at each end.  I only have one so that's no good.
>>>
>>> Assuming that there is no such double adaptor device that I can use to
>>> get me a fifth port, the only solution I can see is to drag out the Edimax
>>> router I have here which is no longer being used.
>>>
>>> Assuming I do this, I'm wondering how to configure it.
>>>
>>> I'm guessing that it will actually have to route.  I can't see myself
>>> doing bridging because there'll have to be two devices on it (the router
>>> will need to take up one of the 4 ports on the modem/router so this then
>>> leaves 5 devices and only 3 other ports,).
>>>
>>> Presumably I need to configure the WAN port so that it connects to the
>>> existing network.  Do I need to set aside a subnet of the 192.168.2.x
>>> network specifically for the second router, or can I just enlarge the entire
>>> network and have it all just cope, with the right packets going to the right
>>> places?
>>>
>>> My preference would be to be able to keep it all as one big network, as
>>> I'd rather not have to reallocate static addresses if I can help it, which
>>> I'm guessing I'd have to do if I had to make the second router have its own
>>> subnet of the 192.168.2.x network.
>>>
>>> Netmasks and such tend to confuse me a little and I'm not sure what I
>>> should be doing here, so any suggestions would be helpful.
>>>
>>>
>> Take the un-used router; Go into its configuration; Disable the Internal
>> DHCP server; Verify that the router does not have an IP address which
>> already belongs to any other device in your LAN (if it does, change it to
>> something else. best something on a different netmask altogether...);
>>
>> Then, disconnect one of the devices on your currently active 4 port
>> router; Connect a cable between the now vacant port to one of the LAN (note:
>> NOT the WAN!) ports of the un-used router. Then you can use the extra vacant
>> ports of the previously un-used router as an extension to your existing
>> network. (The 4 ports in any common router are actually a switch...)
>>
>> Good luck,
>>
>> -- Shimi
>>
>>
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>>
>>
>
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