Beginners guide to network switches

[T i m]

+1

Cheers, T i m

[tony sayer]

All pro two-way radio broadcast TV and VHF FM & DAB are 50 ohms as are the cable connectors, transmitter outputs etc. Most all using dipoles as the radiating elements have a "BALUN" BALance to UN Balance transformer.

Some use Gamma or Delta matches but the idea is the same to match the balanced dipole to the un balanced co-axial cables except those occasions where LF MF and HF arrays are used.

Quite a complex subject overall!....

[tony sayer]

That might be a loading coil...

Well your average Taxi will have a straight rod "somewhere" around a quarter wave; thats matched via it being the right length to a 50 Ohm feeder cable to the 50 Ohm transceiver.

But its going the way of the dodo these days a lot are now using smartfone apps over cellular networks....

[The Natural Philosopher]

Which matches as well. Once you have anything other than a pure aerial in the mix, you can run at any arbitrary impedance.

But in the contexxt of finding a use for 50 ohm cable domestically, good luck with that.,

very.

[T i m]

Yup.

Possible but in most cases I doubt it.

Quite. Most of that I did and outside hours, simply because it was easier (that trying to get everyone off the net) and quicker. Or I would go in over the weekend if it was a longer job and take the time off in lieu.

Like things (inanimate and otherwise) that can sense you are in a rush or that things are important and play up accordingly, you could guarantee that if I had some new hardware to install or something that required a bit of piece and quiet to read up on or configure properly the phone wouldn't stop ringing (I ran the 'Telephone Help Desk' for customers) or there would be a constant flow of users though my door with (mostly finger) trouble. Hence why I'd often leave it to outside working ours.

ThickNet was handy if you had a long thin building but ours was several 'wings' over a couple of floors so a Star topology was better suited.

It didn't even exist when I first offered to put 'a network' into our building . My logic for proposing it to them was that 'We are a datacoms Co after all' and 'it would save a lot of time' (and so money) versus 'Sneakernet'. ;-)

I've had to take such things out of daily use because it always seems the 'good' mugs get broken whilst the 'couldn't care less' mugs will survive being dropped on concrete. ;-(

Cheers, T i m

[T i m]

You can get 'isolation' between machines on some routers but a managed switch might be good for my mate in the PC shop to isolate customer machines in for repair from his own / shop machines? Or I wonder if you could use the OpenWRT router software (two LAN ports) I installed on his TP-Link cable router to in turn feed two switches (one for the shop and another for the 'guest' machines)?

He would have to have the WSUS server on the guest network as they are the ones that need updating.

Cheers, T i m

[T i m]

I had to do similar for a mate the other day. OpenReach modem to BT Hub to an 8 port switch. They had been speaking to BT and BT had asked them to pull the power leads from the PC's. Luckily they had only pulled the power leads from the monitors .

The 8 port switch was showing some strange signs and a power cycle didn't seem to resolve it. So I pulled all the Ethernet cables and just connected the link to the router and one PC. All was well so I just re-connected the known leads (to local PC's and printers) one at a time and all stayed well. Plugging one of the last two cables in seemed to upset the switch so I left them unconnected (as no one knew where they went in any case). I'm sure they will hear if someone (or thing) doesn't have any Internet connection. ;-)

Cheers, T i m

[John Rumm]

Yup, very much so...

There are lots of ways of doing it. He possibly need a customer wifi network as well - where devices can access the internet, but not see each other or the rest of the LAN

[Chris J Dixon]

I may well want to connect more than 4 items to my router, and following your suggestion I found this Amazon page:

At the time of writing, the GS108 is £25.00, and the GS108Ev3 is £25.77. Is there any point in buying the fractionally more expensive (because it is more heavily discounted) managed switch, when I don't currently envisage that I need the extra facility?

Chris

[John Rumm]

For home use there are probably only a few features of a managed switch that might be of use:

Spanning tree detection - this allows the switch to spot when a network loop has been created, and block the port causing the problem. (on an unmanaged switch if you connect one port directly to another on the same subnet it can cause the broadcast storm that brings the network to it's knees.

Link aggregation - allows multiple ports to be joined into a logical channel for higher throughput. Handy with the posher NAS devices that have multiple gig ethernet ports. It does not improve the max speed of delivery to any one user (unless they are using multiple network interfaces, but does allow concurrent full speed access to multiple machines (drive throughput permitting))

VLAN support - allow the network to be logically partitioned into separate walled gardens - handy for example if you want CCTV cameras on the lan but don't want to have an externally accessible lan connection that can access sensitive parts of your network.

I would agree with Tim that generally Netgear switches are good (although did havea recent problem with a couple of new 24 port PoE ones that were crashing about once a fortnight. However those have been ok for the last few weeks after I did a firmware upgrade on them). TP-Link ones seem to be pretty rock solid as well.

[SH]

when I bopught my current house 10 years ago, I bought one of these 2nd hand off eBay:

been in the loft ever since, only issue I had was overheqting when the fans failed ( a common problem) replaced all the fans and its not missed a beat since.

All the TVs, radios, set top boxes all have ethernet connections as well as the desktop and laptop PCs and also 4 NASes and 1 DVR, so its easy to fill up the 48 ports quickly in a 5 bedroom house! :-)

[lacksey]

What is the point of quibbling about £0.77 ?

[Theo]

That's a so-called 'smart' switch, which isn't a proper managed switch (won't tie into a corporate network so well) but is probably easier to use for a home user.

The main things to be aware of is the smart switch has an IP address of its own (for the control panel) and it may take fractionally more power than a dumb switch. The IP address is only likely to be an issue if using it somewhere unusual, like on the WAN port of your router (hint: don't do that).

Power-wise, the GS108 is now EOL so likely an older design, but:

Maximum power consumption GS105: 3.5W GS108:

- 4.92W (if cable length > 10 m)

- 4.08W (if cable length < 10 m)

GS105Ev2: 2.6W GS108Ev3: 4.5W

so actually the newer 'smart' design is slightly better in terms of power consumption.

For the extra 77p it seems a no-brainer.

Theo

[Chris J Dixon]

My NAS does have this facility, but I'm not at all sure that there is sufficient simultaneous demand to make it worthwhile.

I guess I would also have to run some more cable. I put in one Cat5 at a time when I could get access. Anything additional would have to be run externally around the house. More wired points in the upstairs "office" could be useful. Any pointers?

Chris

[The Natural Philosopher]

Inside a domestic firewall unless you are running a massive network there is absolutely no reason at all to have a managed switch. In a huge corporate network, perhaps.

I cannot remember the last time I did management at MAC level though - once TCP/IP came in if you wanted to fine tune things you used a router

+switch instead of just a switch.

[John Rumm]

More wired points is easy - you just need a switch :-) More points to do link aggregation really needs more cables, unless you can get your existing one running at 2.5G (but more cat5 would still be cheaper)

[RJH]

Agreed on the TP link and Netgear - I've had one of each on continuously for about 10 years and no problems (yet).

I'd look for a metal case, and check the ports/power socket are accessible and easy to route at your chosen spot.

That'll be costing over £100 a year to run. Basic switches a fraction (less than a tenth) of that. But obviously if it suits your needs, looks to be an impressive bit of kit.

[www.GymRats.uk]

little Netgear switches are extremely reliable form my experience.

I still have the first Netgear firewall/router I bought for the shop 20+ years ago in operation as Wi-Fi access point (FWAG114). and an 8 port and a 16 port switch both retired from business use but re-purposed on the far more hectic home-network. The only downside to Netgear kit is the external PSU which I've had to replace numerous times both manufacturers original which actually went up in smoke, and a switch-mode non OEM replacement.

My TPLink managed switches have a few semi handy features, one showing "cable length" of the wire connected to each port but on the whole they (managed switches) just sit doing their own thing.

Always go for the latest version available, it will be more energy efficient and have more updates for longer.

Cheers - Pete

[Andrew]

New GS105 going cheap on the BHF website if you want a basic one. I suspect no-one will bid for it.

[John Walliker]

Or even cheaper, accounting for postage, would be one of these. I have a few. They are very well made with a solid steel case. Amazon UK product code: B07HP5TN4S The current price is £12.99 with free same day prime delivery. John