Linux Format forums

Re: Networking over mains - ethernet

spottedcat — Tue Apr 11, 2006 10:53 am

Author: spottedcat

Posted: Tue Apr 11, 2006 10:53 am

jhooks wrote:

In a star topology network e.g. twisted pair ethernet (10/100BaseT), you require a hub or switch (switching hub). The Devolo devices may use either a bus topology (like 10Base2), or more likely a ring topology (most homes have a ring main).

Thanks, I'll bear that in mind if I have to extend my network. With my present setup I managed to save a bit of money by buying an ethernet switch (�25 from PCWorld) instead of having to get more than the starter pack's two MicroLinks (at about �60-70 for each single one!).

Re: Networking over mains - ethernet

jhooks — Tue Apr 11, 2006 9:39 am

Author: jhooks

Posted: Tue Apr 11, 2006 9:39 am

nelz wrote:

Yes you can connect more than one device to a single port on a router, by running them through a hub or switch. The Devolo devices must contain the necessary to enable each to act as a hub for the others.

Re: Networking over mains - ethernet

shifty_ben — Mon Apr 10, 2006 10:10 pm

Author: shifty_ben

Posted: Mon Apr 10, 2006 10:10 pm

Good to hear they are worth getting, I may well invest in a pair then, have been wondering about sticking a PC in the loft for Media, but as I rent I can't run Network cables up there. Excellent

Re: Networking over mains - ethernet

spottedcat — Mon Apr 10, 2006 5:15 pm

Author: spottedcat

Posted: Mon Apr 10, 2006 5:15 pm

Hi. I've now bought a pair of Devolo MicroLinks. The box says "one minute installation" and they're not joking. Configuring my own encryption password took only a little longer.

Before buying, I looked at the adslguide reviews (Solwise here and dLAN MicroLink here) but went with the more expensive. Whatever, I'm impressed. My setup is now modem-router > MicroLink > mains > MicroLink > Belkin ethernet switch > various PCs. The two MicroLinks are one upstairs and one downstairs, on two different mains rings. Even so, the devolo configuration software tells me I am getting 82-83 Mbps.

BTW, the review in LXF79 says that Linux software is available for download. Actually, <cough> <cough> it's on the CD that comes with the kit. In /software/linux to be precise - <cough> <cough>. Nice to see a tar.gz filename there. There's even a readme file with instructions for installing in SuSE and Debian. Got it working nicely in SuSE, thankyou.

Re: Networking over mains - ethernet

shifty_ben — Sun Apr 09, 2006 11:15 pm

Author: shifty_ben

Posted: Sun Apr 09, 2006 11:15 pm

Sitting out in the garden is great until you realise that everything you normally use is inside, SANE may let you do network scanning, but theres no way for you to change to the next document from out in the garden!

Having said that, sitting in the garden, with a beer and the laptop playing a DVD or streaming audio/video from a TV card in another computer is quite nice. My wireless AP only gets switched on when I need it, it takes less than 5 seconds to boot up, so theres no point in risking the security of the rest of the network.

Quote:

Notwithstanding that ALL wire connections emit a signal. If you've got the right kit, you can pick it up.

Interesting you say that, because it occurred to me earlier that because of that these devices may be more secure than an ordinary wired connection a) some of them offer encryption - though what ive read seems to suggest it is actually just software encryption so the device is more or less irrelevant. but more importantly b) because of the background noise generated by the mains current, not to mention anything generated by "high-noise" appliances it should be a little harder to pick up the signals you need to listen in. Not impossible mind you.

Incidentally depending on the size of your house and wallett and the layout even with thick walls it is possible to get good wireless coverage, by placing repeaters in choice locations. You can build a repeater quite easily, especially if you have an old wireless router (or several) lying around. Problem is a) power consumption b) setup costs and c) finding the right place to put the things.
Far easier just to spend out on one of these things for each room you want it in I think.

[edit]

I'm in no way suggesting wireless is as/more secure as using cables. It isn't. With wireless you are in effect placing no physical limit on the distance of your network. In fact if someone was that determined they could build 'repeaters' as described above, and with correct placement and careful planning access your network from the comfort of their home a mile away. Its a pretty unlikely event though, far easier to sit in the car

Re: Networking over mains - ethernet

bigjohn — Sun Apr 09, 2006 10:44 pm

Author: bigjohn

Posted: Sun Apr 09, 2006 10:44 pm

telboy wrote:

Have you considered the Devolo MicroLink dLan adaptors featured in this months magazine? (quoted at the wrong price I'm afraid - appear to have left a 1 off the front of the amount)
{snip}

TVM for that "pearl", it means that for me, I'll probably go for 2 of the Solwise devices, as at �86 the pair (actually I'll need 3 so it'll be �129) it looks cheaper than the Devolo Microlink option.

The only downside being that I'll have to complete the 3 year electrical installation course (with full NICEIC accreditation) to get rid of the snakes wedding for all the various devices I've got plugged into just 2 mains sockets at the moment

regards

John

p.s. Oh and for those who seem to think that wireless is more secure - having worked in "communications" in a previous life, I can confirm that it's easier to pick up a wireless signal, than it is to pick up a signal thats being passed down a copper wire.

Notwithstanding that ALL wire connections emit a signal. If you've got the right kit, you can pick it up.

Hence, it's more about the use of the correct cryptographic protocols and softwares. The main issue for me is that the freq ranges used for wireless devices are so high, that they are effectively "line of site", and as someone else already mentioned, it's quite feasible to stuggle to get a decent signal even in the next room.

I suspect that I'll stick to my wired connections - I have no desire to sit out in the garden with a laptop - irrespective of what the bloody adverts say!

Re: Networking over mains - ethernet

spottedcat — Thu Apr 06, 2006 8:08 pm

Author: spottedcat

Posted: Thu Apr 06, 2006 8:08 pm

Thanks, nelz. That's very helpful. In fact I've got 3 PCs sitting next to each other with a KVM switch. (Don't ask - it's a long story.) At the moment - 3 ethernet cables. From what you say I could get a hub/switch to connect the three to a single devolo thingy. That means I would need only 2 microlinks instead of 4. At about 70 smackers a go that would be a lot cheaper.

OK. If I go ahead, I'll post my experience in this forum.

Thank you both, nelz and shifty_ben.

Re: Networking over mains - ethernet

nelz — Thu Apr 06, 2006 7:51 pm

Author: nelz

Posted: Thu Apr 06, 2006 7:51 pm

Yes you can connect more than one device to a single port on a router, by running them through a hub or switch. The Devolo devices must contain the necessary to enable each to act as a hub for the others.

Re: Networking over mains - ethernet

spottedcat — Thu Apr 06, 2006 5:56 pm

Author: spottedcat

Posted: Thu Apr 06, 2006 5:56 pm

Thanks - so that would mean - in effect - that if one had a suitable Y-piece, one could plug 2 computers into the one socket of the router, and each would still have its own IP address? Not that I would want to - but I'm just trying to understand.

Edit: the more I think of this, the more it doesn't add up. I should have provided a link to the Devolo 2comps/1router setup so HERE it is. In effect, 2 computers are being stuffed into one RJ45 on the router.

Re: Networking over mains - ethernet

shifty_ben — Thu Apr 06, 2006 5:53 pm

Author: shifty_ben

Posted: Thu Apr 06, 2006 5:53 pm

As long as my understanding of how they work is correct then the answer is Yes. AFAIK all the adaptor does it adjusts the pulses received from the router into something that isn't going to get outshouted as it were by the mains frequency. SO theorretically if you have two computers next to each other you should be able to get away with one of the devices in the room and then a switch between that and the two PCs. It does seem to work just as an extension of the cabling.

HTH

Ben

Re: Networking over mains - ethernet

spottedcat — Thu Apr 06, 2006 5:33 pm

Author: spottedcat

Posted: Thu Apr 06, 2006 5:33 pm

I need to ask an irritatingly elementary question.

The devolo (MicroLink dLAN - reviewed in LXF79) website shows a setup for 2 computers to be connected simultaneously to the internet, as follows: Router connected to a single MicroLink device via a single ethernet cable, then 2 computers each connected to their own MicroLinks in other rooms. 3 MicroLinks altogether - 3 ethernet cables. Makes sense. But can a router communicate at the same time down one cable, assigning different IP addresses to each machine? The Devolo website seems to imply that this is so, but I would like confirmation of this before I decide whether I want to buy these expensive bits of kit.

Excuse my ignorance. It seems such a basic thing to have to ask.

Re: Networking over mains - ethernet

shifty_ben — Wed Apr 05, 2006 12:48 pm

Author: shifty_ben

Posted: Wed Apr 05, 2006 12:48 pm

True, it does make it less trivial but it takes a lot less to get the information you need to spoof than you might think. Having said that If your router is linked up to the Internet then theres always a risk of security breach so you could argue that having wireless presents little more of a risk

Re: Networking over mains - ethernet

emyr42 — Wed Apr 05, 2006 2:55 am

Author: emyr42

Posted: Wed Apr 05, 2006 2:55 am

Don't more wireless routers do MAC filtering nowadays? I know it's spoofable, but it makes it a lot les trivial.

Re: Networking over mains - ethernet

shifty_ben — Tue Apr 04, 2006 11:57 pm

Author: shifty_ben

Posted: Tue Apr 04, 2006 11:57 pm

Wi-fi is quite dependant on where you are though, I've been in houses where it is nigh on impossible to get a decent signal in the next room from the router, and others where signal is consistent and strong throughout the house. Granted part of that will depend on the quality of the router and the NICs used, but Wifi can be somewhat unstable. It also poses a security issue, WPA is good but not unbreakable. Still a bit of an issue with this in terms of that, but as the meter acts as a sort of firewall (presumably due to diodes or somesuch) at least they need to get into your house and plug in.
Of course in somewhere with wiring shared between a lot of rooms - University halls, Hotels etc this argument is less valid, but in the home it is probably only marginally less secure than properly wired networking.

Re: Networking over mains - ethernet

emyr42 — Tue Apr 04, 2006 11:06 pm

Author: emyr42

Posted: Tue Apr 04, 2006 11:06 pm

personally, I'd rather be using Wi-fi...