Fixing a network issue.

[Chiyachan]

Magical internet cable (Phoneline) > Thomson Gateway (TG585 v7) > 1 PC and Wireless connections.
                                                                                               > Sitecom (DC-202v6) > PC
                                                                                                                                > NAS

The problem I have is that the wireless connections and the PC connected directly to the Gateway are unable to access anything connected to the Sitecom device. The PC on the Sitecom is able to access internet and the NAS directly. It seems that the PC on the Gateway cannot even access the Sitecom device. The Sitecom PC is able to access nothing over the wireless network or the PC on the Gateway.

Requirement: NAS to be able to be accessed via Wireless and Gateway as well as Sitecom. For everything to be a single network and accessable.

I'm able to provide screenshots/settings of each if you detail what is required.

[Bob2004]

As far as I can tell, both the TG585 and the DC-202 are routers, not switches. This means that they can allow several devices to connect to the internet, but they cannot allow those devices to connect to each other. This is different to a switch, which allows all connected devices to connect to each other, not just to the internet.

The only way to allow all your devices to connect to each other is to buy an ethernet switch, and connect your devices to that. So it will look like this:

internet > Thomson Gateway (TG585 v7) > Ethernet Switch >1 PC and Wireless connections.
                                                                                       > Sitecom (DC-202v6) > PC
                                                                                       > NAS

Basically, anything connected to the ethernet switch will be able to talk to anything else connected to the switch - but not to anything connected to the TG585. I'm not sure if you'll be able to get away with having multiple devices connected to the Sitecom or not, if it's behind the switch, so you'll have to experiment with that. I have a similar setup at home myself, with fewer devices, and it works well.

EDIT: Something like this will work very well for the switch. You can probably get a similar one with fewer ports for cheaper if you look around a bit, but I'd try and avoid the really cheap ones, since they tend to be less reliable.

[Chiyachan]

Not really that do-able as the Sitecom is upstairs. I only really want one wire going upstairs to NAS, PC and few other connected items.

[Bob2004]

I've done some experimenting with the network equipment I have here, and I'm pretty sure that so long as the switch is between the Sitecom and the modem, any devices connected to the Sitecom *should* be able to talk to each other, so the switch could just have one wire going in and one going out (to the sitecom), and not impact your current layout too much at all. You're not going to be able to do it without a switch somewhere in your network, though.

Alternatively, you might be able to find a switch which doubles as a wireless access point, which you could use to replace the Sitecom entirely, perhaps. I've never seen one before, but they might exist. Similarly, you might be able to find a switch which doubles as a modem to replace the Thompson gateway, but that's very unlikely due to the nature of switches - and the ease of just using multiple devices. Vendors have an annoying tendency to use 'router' and 'switch' interchangeably to just mean 'router', so double check anything like that you find before you buy it.

[Chiyachan]

So put a switch downstairs next to the Thomsom and have my cable up to the Sitecom, but have other computer connected to Switch downstairs.

I'll give that a go at some point soon.

Still recommending an item like this? http://novatech.co.uk/products/networking/switches/2-8portswitches/fs108uk.html

[Bob2004]

So put a switch downstairs next to the Thomsom and have my cable up to the Sitecom, but have other computer connected to Switch downstairs.

I'll give that a go at some point soon.

Still recommending an item like this? http://novatech.co.uk/products/networking/switches/2-8portswitches/fs108uk.html

Yep. You could also have your other computer connected to the Sitecom, and it should work fine, if that works better for you. So long as the switch is between your network and the Thompson router, it should work fine.

And yes - I have this one in my home network, and it's worked very well for me.

Also, I'm not sure how you have your network set up at the moment, but make sure your sitecom is just acting like a wireless access point rather than a router (ie. it isn't assigning IP addresses to devices connected to it). Everything needs to be on the same network, if at all possible.

[Freedom Kira]

Basic rule is: don't chain routers; use only one. But chain as many switches together as you want.

[TorturdChaos]

If you can find a way to put the second router into a switch only mode, and get all its commands from the first router - that works.  I have done that a couple times with Linksys WRT54G / GS / or GL routers with DDWRT firmware on them.

But if you have routers chained together and still acting like routers - each router is gong to want to use a different subnets.  So one will be on something like 192.168.1.x and the other one 192.168.2.x.  Things connected to different routers won't want to talk to different subnets.

We have our network setup like that in one of our stores so customers can access WiFi, but not our server or computer.  Its setup like so:
Cable Modem /w WiFi Router -> Linksys Router -> Cisco Switch.

People connected to the WiFi cannot talk to any computer connect to the Switch (which gets all its commands from the Linksys Router).