AcusTwinhammer t1_j9ijkez wrote
Router: Routes packets at the IP level.
Switch: Routes packets at the layer 2/MAC address level.
So a packet going out gets to a router, the router decides by IP address where that packet needs to go. If that IP address is "local" to the router, that is in a subnet the router has ownership of, it then uses switching to send the packet to the destination. Most modern routers have some switching capability, and most switches have some routing capability.
Hubs: Really dumb switches. A switch will keep track of connected devices, so if a packet is going to destination MAC aaaa.bbbb.cccc.dddd, it knows that MAC is on port 7 and sends it to that port. A hub does not keep track of such things and just sends the packet to every connected port. There may be some use cases for hubs still, but generally they should be avoided.
Bridge: generally a point to point link of some kind. For example, if you have two office buildings, the main one has the main network, but the second one needs to connect but you can't run any sort of standard ethernet arrangement, you might set up some sort of point-to-point wireless bridge connection.
Modem: Changes signal type. For example, cable internet does not use ethernet. So the cable modem is what changes the ethernet packets to the DOCSIS protocol on the cable coax.
Access Point: WiFi. Is the communication point for end devices using WiFi to talk to the network. Wireless broadcast, so arguably more of a hub than a switch in such terms.
Transceiver: The physical component in a router or switch that is turning the packets into flashes of light on the fiber line.
Repeater: If your signal has to go a long distance on the wire, it may not be strong enough to make it. So a repeater will just take the signal coming in and blast it out the other. The bonfires between Rohan and Gondor are repeaters.
Range Extender: I generally hear this with WiFi, essentially trying to do the same thing as a repeater, but it's sometimes a little more complicated since WiFi is broadcast radio.
fubo t1_j9ikprt wrote
> There may be some use cases for hubs still, but generally they should be avoided.
There is no such thing as a hub for modern wired Ethernet anyway; Gigabit Ethernet requires switches and full-duplex links.
(One thing we used to use hubs for is security monitoring: run your Internet traffic through a hub and attach the intrusion detection system(s) there; since the hub mirrors all traffic to all ports, your IDS can sniff it all. These days you'd use a network tap or a span port for that.)
oraanglewaat OP t1_j9k06sj wrote
Thank you, kind Redditor.
With u/FilthyWeasle 's, u/zhonzhon 's, and your explanation, I understand a little bit better.
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