johnfaig
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hub vs switch
What is the difference between a hub and switch? I was looking at a Linksys EZXS88W and Linksys EFAH08W because I needed a few more ports on my router.
Thanks
JDF
Thanks
JDF
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I did some digging and the Linksys docs say that a hub does not function as a repeater. It needs to be close to the ohter network equipment. The docs say that a switch can be far (300+ feet) from the other piece of equipment. Does this factor into the decision?
JDF
JDF
You've pretty much gotten the description of the difference betwen the two. Maybe Linksys might have switches that also act as repeaters, but switches are not repeaters in and of themselves. But for your purposes, it sounds like a switch should easily do the trick plus you'll get better performance.
Are you looking to expand your network over a fairly noticable distance? If so, maybe something like a wireless network would do the trick? Or even a powerline network in combination with your existing one?
Are you looking to expand your network over a fairly noticable distance? If so, maybe something like a wireless network would do the trick? Or even a powerline network in combination with your existing one?
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Hi,
I would like to see where you read that. I believe that you read it somewhere, but I don't believe that it is correct. In essence, a hub is a repeater, otherwise it wouldn't "repeat".
Ethernet (the transmission of data over Unshielded Twisted Pair, UTP, with or without switches or hubs) is spec'd for 100 meters (approx. 300 feet) per length of cable. Adding a repeater (a Hub is really just a mulitport repeater) extends the distance by another 100 meters. There is a limit to how many times you can repeat this, and it is commonly called the 5-4-3 rule, and it's explained here:
http://www.webopedia.com/TERM/5/5_4_3_rule.html
This limitation is primarily caused by a technical requirement that anything transmitted on the "segment" arrive at it's destination within a certain amount of time. This is due to timing constraints that the various network devices use to help reduce "collisions" in the "domain", or the segment. A hub does not break the network into segments, but a switch does....
A switch actually receives the data packet, checks it for integrity, reads the destination address, and forwards it on it's next hop. I do not believe that the 5-4-3 rule applies to this, since the timers are for a given "collision domain", and when it crosses a switch it changes "collision domains", or "segments".
But the Ethernet technology remains the same as far as cable quality and cable lengths and such goes. The technology was built on top of technology. First there was something else that I don't want to get into just now, then Ethernet (10BaseT), then came repeaters followed by multiport-repeaters called hubs, then came smart hubs that could repeat in a smarter way and they were called switches. About this same time something called Fast Ethernet came along that bumped the 10 MBit, called 10BaseT, to 100 MBit, called 100BaseT. Same technology but with faster data signaling over better cable.
If Linksys says it's not a hub and should only be used close to other equipment, I'd be very leary of it. Linksys generally makes good stuff, so I'm a little concerned about them saying something like this.
I've gone into a LOT of detail about how ethernet works, and really, it may not even matter in your environment. If we are talking about hooking up two PCs so that both can get out the dsl modem, then it's not really going to matter. If we are talking about some PCs accessing files on a server and some more PCs printing to network printers and some more PCs accessing the internet, then that's something else. Basic concepts are: A Hub only allows one device to talk at a time. A switch allows multiple devices to talk to different devices at the same time. Think of it as a bunch of people with single channel radios compared to a bunch of people with multichannel radios.
Let me know if you need more.
Alan
I would like to see where you read that. I believe that you read it somewhere, but I don't believe that it is correct. In essence, a hub is a repeater, otherwise it wouldn't "repeat".
Ethernet (the transmission of data over Unshielded Twisted Pair, UTP, with or without switches or hubs) is spec'd for 100 meters (approx. 300 feet) per length of cable. Adding a repeater (a Hub is really just a mulitport repeater) extends the distance by another 100 meters. There is a limit to how many times you can repeat this, and it is commonly called the 5-4-3 rule, and it's explained here:
http://www.webopedia.com/TERM/5/5_4_3_rule.html
This limitation is primarily caused by a technical requirement that anything transmitted on the "segment" arrive at it's destination within a certain amount of time. This is due to timing constraints that the various network devices use to help reduce "collisions" in the "domain", or the segment. A hub does not break the network into segments, but a switch does....
A switch actually receives the data packet, checks it for integrity, reads the destination address, and forwards it on it's next hop. I do not believe that the 5-4-3 rule applies to this, since the timers are for a given "collision domain", and when it crosses a switch it changes "collision domains", or "segments".
But the Ethernet technology remains the same as far as cable quality and cable lengths and such goes. The technology was built on top of technology. First there was something else that I don't want to get into just now, then Ethernet (10BaseT), then came repeaters followed by multiport-repeaters called hubs, then came smart hubs that could repeat in a smarter way and they were called switches. About this same time something called Fast Ethernet came along that bumped the 10 MBit, called 10BaseT, to 100 MBit, called 100BaseT. Same technology but with faster data signaling over better cable.
If Linksys says it's not a hub and should only be used close to other equipment, I'd be very leary of it. Linksys generally makes good stuff, so I'm a little concerned about them saying something like this.
I've gone into a LOT of detail about how ethernet works, and really, it may not even matter in your environment. If we are talking about hooking up two PCs so that both can get out the dsl modem, then it's not really going to matter. If we are talking about some PCs accessing files on a server and some more PCs printing to network printers and some more PCs accessing the internet, then that's something else. Basic concepts are: A Hub only allows one device to talk at a time. A switch allows multiple devices to talk to different devices at the same time. Think of it as a bunch of people with single channel radios compared to a bunch of people with multichannel radios.
Let me know if you need more.
Alan
Hi johnfaig,
hub and repeaters work on layer 1 (physical layer) where any signal is regenerated across all ports. Hubs can be said to be multiport repeaters.
Switches and bridges work on layer 2 (datalink layer) where data is forward to the ports based on the location of the destination MAC address.
For what it is worth, hubs and switches cost about the same, and that is assuming that hubs can still be purchased. The maximum distance between a hub or switch to a device is the same (100 meters).
Regards,
hub and repeaters work on layer 1 (physical layer) where any signal is regenerated across all ports. Hubs can be said to be multiport repeaters.
Switches and bridges work on layer 2 (datalink layer) where data is forward to the ports based on the location of the destination MAC address.
For what it is worth, hubs and switches cost about the same, and that is assuming that hubs can still be purchased. The maximum distance between a hub or switch to a device is the same (100 meters).
Regards,
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A hub is good, works great, not considered as fast. A switch is better, allows multiple traffic at the same time, etc.
A hub hears something on one port and repeats it on all others, always.
A switch hears something on one port, looks up the MAC address for the destination and forwards it out only the port that MAC address (network card) is on. If it doesn't know, it repeats it on all ports, but only until it hears that port then it learns about it and remembers where it is.
Hope this helps,
Alan