Switch or hub

[pcslookout]

Do I need a switch or a hub to extend a Ethernet port from 1 connection to 4 ?

 

[Puffnstuff]

You need a switch and one of the ports on it will be the feed from the source leaving the rest of them free to plug other devices into. You can also daisy chain switches together to get the amount of ports you need for your network up to the limit of your router dchp capability.

 

[JackMDS]

You need a 5Port Switch.

Example - http://www.newegg.com/Product/Product.aspx?Item=N82E16833156250

 

[Gryz]

A switch will work.
A hub will work too.

The problem is, if I'm not mistaken, that it becomes harder and harder to actually find simple hubs. Switches are so cheap that it's hardly worth producing hubs. And if you find a cheap hub, it might be an old one, which only supports 10Mbps or 100Mbps, and not 1Gbps. (If you buy a switch or hub these days, you probably better make sure it can do 1Gbps).

A few years ago I needed to buy a hub. A hub would have been just as good as a switch in my case. But I couldn't find one. So I ended up buying a cheap switch for 15 euros.

To be clear: there is only one scenario where a hub would be better than a switch at home. If you have 2 high-bandwidth streams of data going from machines A and B to machines C and D. And at least 3 of those are directly connected to your switch/hub. In that scenario the 4th one can be upstream of your switch/hub, or even on the Internet (if you have very fast Internet). This scenario is pretty unlikely for most people at home.

Suppose we got this scenario:
1) Your PC at home, with a 1Gbps connection.
2) Your laptop at home, with a 1Gbps connection.
3) A NAS with 1Gbps connection (and 1Gbps performance. Good luck with that).
4) A fast Internet connection (let's say 100Mbps at least).

Machines 1), 2) and 3) are connected to your hub or switch. So is the router. Let's call them PC1, LT2, NAS3, and RTR4.

Suppose you use a hub.
All packets received by the hub are copied on all other ports of the hub. So if PC1 sends a packet, LT2, NAS3 and RTR4 will all receive the packet.
Suppose PC1 sends a lot of data to NAS3. E.g. it is doing a backup. Suppose PC1 and NAS3 are so fast, that they communicate at max speed. That is 1Gbps from PC1 to the hub, and 1Gbps from the hub to NAS3.
Now it is important to realize that that means that the links hub->LT2 and hub->RTR4 will also be fully filled with those backup-packets from PC1.
Now suppose that a user on LT2 wants to watch NetFlix from the Internet. Let's suppose it's 4k and the stream takes up 100Mbps. 100Mbps arrives from the Internet on RTR4. RTR4 wants to forward those packets to LT2 via the hub. If the link between RTR4 and the hub is full duplex, that should not be a problem (1Gbps useless packets from PC1 go into the opposite direction of the NetFlix packets). But if the link is half-duplex, then the 1Gbps of useless packets from PC1 will have filled the link. No room for the NetFlix packets.
But even if the connections to the hub are full-duplex, this doesn't help on the connection from the hub to LT2. Both the NetFlix packets and the useless packets from PC1 are trying to go over the same direction. And there will not be enough bandwidth for both. Congestion. Packets dropped. TCP slows down.

In this scenario, a switch would help. Because the switch will only copy packets out over the link connected to the destination. In our case, the backup-packets from PC1 will only be sent over the links PC1->switch and switch->NAS3. And the NetFlix packets from the Internet will only be sent over the links RTR4->switch and switch->LT2. There is no overlap. So no congestion. And both flows of packets can go full speed.

However, I'd say that scenario is pretty unlikely at home, if you run 1Gbps on your home network. Most NASes can not perform at 1Gbps. And people don't do constant backups. And usually their Internet speeds aren't that large. Suppose you watch NetFlix at 10Gbps, would it really be so bad if your backup now runs at 990Mbps in stead of 1Gbps ?

I googled a bit more to see if you can buy ethernet hubs. It seems there are none for sale anymore. So a moot point. Buy a switch. But in theory, a hub would be just as good at home (most of the time).

 

[smitbret]

A hub will work if that's all you can get but otherwise a switch will offer noticeably better performance in everything a normal home would need and is worth the price premium.

You don't need to spend much. NetGear, Linksys/Cisco, TrendNet, TP-Link, D-Link are all good brands for unmanaged switches and unless you have a need for any special features, there's no real reason not to just get the least expensive one.

JackMDS's recommendation is a good one.