THE DIFference

[@ng3lu$]

Cany someone explain to me what is the difference between router, bridge and switch or if there are some other hardware network things.

[The Grunt]

A bridge connects two networks at the 2nd (network) layer rather than the 3rd (Transport) layer like a router... A switch connects various computers on the same network. Bridges are all hardware I believe, routers always have some sort of imbedded OS...

[jinxy]

Take a look at the thread below, it pretty much explains everything for you with some usfefull links:

http://www.antionline.com/showthread...network+bridge

[@ng3lu$]

so if switch connects many computer within the network, so a hub is a switch?

[IKnowNot]

so if switch connects many computer within the network, so a hub is a switch?

No.

Think of it like this: a switch is an intelligent hub.

A hub would connect everything to everything. A hub will look at packets coming and send them to everything on the hub, then what needs it grabs it.

A switch will look at what is coming in, find where it should go and only send it down that one path.

[Moissonite]

No. A hub is the prostitute of a network. Basically it just allows traffic to travel from computer to computer without any questions. If you have 20 machines connecting through a 10mbps hub, the signals are transported simultaniously to the server. This slow down the connection as it consumes the bandwidth and also allows for collision of packets. The data cannot be directed in any way via the hub - it simply connects a-b and back again. The data is insecure and packets can be intercepted at any point within the network.

Switches are more intelligent, allowing the transfer of data from one specific computer to another. Although similar in operation to a hub, the added control allows more security as the packets are not just wandering everywhere, no packet collission and less degredation of bandwidth. They connect computers together via IP addresses or Mac addresses - this is done by the ARP and rARP protcols.

Switches and routers also allow the assignment of internal IP addresses (NAT or NO-NAT) though the connection of one network to another (internetworking) is the job of a router.

So:

Hub: shares traffc on a network: no security, no assignment of addresses, collission a possibility, bandwidth nightmare - basically a carrier

Switch: Shares traffic intelligently on a network. Connects computers together via IP addresses or Mac addresses. Can assigns IP addresses internally. Is more secure. Stops collissions, bandwidth friendly - bascally a team of loyal carriers

Router: Shares trafffic intelligently accross networks. Usually connects to a switch or hub. IP config, port forwarding, fireall etc etc. - the team who dispach the team of carriers

I hope that made sense to you - my hangover prevents my brain from flowing very well today

[Irongeek]

Originally posted here by Moissonite

Switch: Shares traffic intelligently on a network. Connects computers together via IP addresses or Mac addresses. Can assigns IP addresses internally. Is more secure. Stops collissions, bandwidth friendly - bascally a team of loyal carriers

To my knowledge, switches only look at the Data Link level. They will look at MAC Addresses, but not IP addresses to tell where to send a packet. A Router on the other hand will look at the IP address (if it's a IP router and not some other protocol).

[ikalo]

There are Layer 3 Switches that can "see" IP address. They are some kind of hybrid of classic Layer 2 swithc and router.

[ikalo]

Also, I forgot to mention, bridge is just like it's name says, a bridge between two parts of network that is to farr away for selected medium to reach. We all know that every network has its limits. For example Ethernet can reach only cca 250m on one cable. There comes bridge, it amplifies signal so it can reach another 250m.

[ss2chef]

Originally posted here by ikalo
Also, I forgot to mention, bridge is just like it's name says, a bridge between two parts of network that is to farr away for selected medium to reach. We all know that every network has its limits. For example Ethernet can reach only cca 250m on one cable. There comes bridge, it amplifies signal so it can reach another 250m.

Or it can simply be used to change to a different media type.

Fiber to copper
ATM to Ethernet (many ADSL "modems" are simply an ATM bridge)