# Can I add an ethernet switch to an ethernet switch?



## OM2 (Oct 28, 2007)

Can someone tell me: can I add an ethernet switch to an ethernet switch?

I've just bought a 4 port model.
I've qucikly realised I need more ports!

Can I just buy another ethernet switch and extend?

Thanks.


OM


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## fairnooks (Oct 1, 2007)

Yes, you just lose one port on each switch in connecting them together or if you have a router you can keep all the ports available by hooking the switches up to individual router ports.


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## OM2 (Oct 28, 2007)

thanks for the reply.
i dont quite understand.
i do have a spare router actually.
i take this router and connect it to a spare port on the ethernet switch.
that leaves me: 3 ports to use on the ethernet switch and 4 on the router - is this what u were saying?
let me know.
thanks.


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## fairnooks (Oct 1, 2007)

I meant if you already were using a router as part of your network. You can use a spare router as a switch by turning off the DHCP service in the router so it doesn't assign local I.P addresses and don't use the WAN port which is not designed for LAN service.

And I brain-farted earlier, you would still lose one port on each switch hooking it up to the router but it is a preferred configuration on more congested networks. It most likely would work well for you either way.


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## OM2 (Oct 28, 2007)

lol. thanks for the reply.

i'm still a little confused.

here's my situation:

i have a router that is connected to the phone line.
i have a long wire that is now connected to my ethernet switch.

can i add a spare router i have to the ethernet switch and thereby get another 4 ports?
what's that about turning off dhcp? is that relevant in what i want to do?
let me know. thanks.


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## TheOutcaste (Aug 8, 2007)

From a post by JohnWill:
Connecting two SOHO broadband routers together.

Configure the IP address of the secondary router to be in the same subnet as the primary router, but out of the range of the DHCP server in the primary router. For instance DHCP server addresses 192.168.0.2 through 192.168.0.100, I'd assign the secondary router 192.168.0.254 as it's IP address.

Disable the DHCP server in the secondary router.

Connect from the primary router's LAN port to one of the LAN ports on the secondary router. If there is no uplink port and neither of the routers have auto-sensing ports, use a cross-over cable. Leave the WAN port unconnected!

In your case connect the secondary router to one of the ports on the switch. If the router has 1 WAN and 4 LAN ports, you will change one switch port into 3 ports on the router. So you will only gain 2 additional connections; Your 4 port switch has 1 port going to the router, leaving 3 for your PCs. Adding the 2nd router will use one of those ports, leaving 2, and adding 3, so you will go from 3 ports to 5.

You need to turn off DHCP in the 2nd router, or the two routers will _both_ be trying to assign addresses to your PCs, which is not good.

Switches can be interconnected with no configuration, just need one with an uplink/auto-sensing port, or a crossover cable. One port on each switch is used for the connection, so connecting a 4 port switch will still only give you 5 ports total, 2 on the original switch plus 3 on the new 4 port switch.

If your router has additional ports, you can run another long wire to hook to another switch (or to the LAN port of the 2nd router); then you would have 3 ports on each device.

It is possible to connect the WAN port to the switch, so all 4 LAN ports on the 2nd router will be available, but this will add a second NAT layer to your network, meaning the PCs connected to the 2nd router won't be able to share files/printers with the PCs on the switch, and vice versa, at least not without a lot of configuration that most cheap routers won't support anyways. Not worth the hassle for one extra port considering how cheap switches are now-a-days. You can find good 16 port switches for around $35-$40

HTH

Jerry


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## fairnooks (Oct 1, 2007)

If you can pick out what you need from the post above, its all in there. It sounds like you have a combination DSL modem and router with one port right? So that router is assigning local I.P. numbers so you would still have to go into the settings of the spare router and turn off DHCP so it doesn't try assigning local I.P. numbers as well. Other than that it should behave just like a switch after that and as stated above, if the ports are autosensing, you can just string them together pretty much any which way.

There are at least two or three other ways to configure a network like that as mentioned in the previous post but this would be the simplest, or just get a big honking 16 port switch or 8 or whatever.


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## OM2 (Oct 28, 2007)

jerry.
that's brilliant. 
thanks a lot.
that's an amazing amount of help.
turn off the dhcp server? i wouldn't have known i need to do this!
i need to add the router anyway to get wireless - would there be any problem with making wireless?
let me know. thanks.


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## TheOutcaste (Aug 8, 2007)

I haven't got into wireless yet, but  it should work just fine. The one sentence I left out of the info from JohnWill was this:
 Setup the wireless section just the way you would if it was the primary router

You didn't mention wireless so I was trying to simplify.

If you browse or search through the Networking forum you should find all kinds of info about your exact setup.

Searching on Connecting two SOHO broadband routers together finds about 95 threads, so there should be something there if it doesn't seem to work quite right.

HTH

Jerry


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## OM2 (Oct 28, 2007)

wow: a lot to read up! thanks.


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