General discussion

Locked

Switches & Routers

By care ·
I am a little confused about the difference between routers and swithces. From reading up on both of them they seem to be simular. A switch just seems to be a much faster router. Am I correct. Is the router placed on the LAN side and a switch placed on the WAN side or is it the opposite way.

This conversation is currently closed to new comments.

12 total posts (Page 1 of 2)   01 | 02   Next
| Thread display: Collapse - | Expand +

All Comments

Collapse -

Switches & Routers

by Greybeard770 In reply to Switches & Routers

A router passes data between networks (subnets).
A switch maintains an ARP table which allows it to create a collision domain for each port. A hub (you didn't ask about hubs) rebroadcasts everything it gets to all ports. Switches can do full duplex while hubs cannot, giving switches a big performance advantage. Routers cost more than switches, which cost more than hubs. You would probably have a router connecting your site to the Internet, but you may have routers inside also if you have multiple networks at your site. You would be less likely to have a switch on the WAN side, but there are reasons to have one there.

Collapse -

Switches & Routers

by care In reply to Switches & Routers

The question was auto-closed by TechRepublic

Collapse -

Switches & Routers

by Alpha-Male In reply to Switches & Routers

This really depends upon the switch in question...as some actually can perform routing (known as layer 3 switches)...but they may really be called router/switch combos.

The basic difference is:

Switches are layer 2 devices and break up collision domains, Routers are layer 3 devices and break up broadcast domains. Switches transmit frames, routers send packets (or datagrams). A switch learns the MAC addresses of the systems connected to it (data link - layer 2) and then acts as a hardware bridge to transfer data only between the needed ports. The router looks at the network address of a machine and directs the traffic to that network based upon one or more metrics to determine the best path. Then it uses ARP to determine the MAC address that corresponds to the IP address to deliver the packets to the host in question.

While layer 3 switches cloud the issue this should give you an idea of the differences.

Hope this helps!

Collapse -

Switches & Routers

by Alpha-Male In reply to Switches & Routers

Oh about the second part...generally Switches will be set up on your LAN (breaking up the collision domains and transferring data to the systems) and the router will be on the WAN (directing traffic to the appropriate network - either internally or externally).

Collapse -

Switches & Routers

by care In reply to Switches & Routers

The question was auto-closed by TechRepublic

Collapse -

Switches & Routers

by carsten.holfelder In reply to Switches & Routers

Lets keep it simple
Switches are used in a Network LAN and it is mainly used to route (direct) the traffic to the destination. It also forwards all broadcast traffic as it comes in out on all the ports.
Hubs are mainly repeaters - what comes in goes out.
Routers on the other hand are mainly used to connect LAN's together to create a WAN. They also block all broadcast traffic. If they are setup correctly the only traffic that will go through a router is the traffic that you want to let through.

Collapse -

Switches & Routers

by care In reply to Switches & Routers

The question was auto-closed by TechRepublic

Collapse -

Switches & Routers

by TheChas In reply to Switches & Routers

You only need a router if you are connecting multiple PCs to a DSL/Cable modem, or multiple networks. Many DSL/Cable routers include a 4 port hub/switch.

If you need to connect more than 4 PCs to the router, you need to add a hub or switch.

For the Linksys Router that I have,
you connect the DSL/Cable modem to the WAN side,
up to 3 PCs to the internal switch,
and connect the external switch to the uplink port.

Chas

Collapse -

Switches & Routers

by care In reply to Switches & Routers

The question was auto-closed by TechRepublic

Collapse -

Switches & Routers

by wbaltas In reply to Switches & Routers

You are correct that a router is normally placed on the WAN side and a switch on the LAN side, but there are other very critical differences.

A router performs three functions:
1. It routes packets between networks that use different addresses. For example, your ISP may use an address such as 198.190.172.0/24, and you may use an address such as 192.168.190.0/24. The router would allow traffic to "travel" between the two address ranges. Without a router a workstation using 192.168.190.100 could not communicate with a server (or another device using 198.190.172.52. The router allows this communication to happen.

2. A router knows the logical network layout and knows how to direct traffic from device to device using the most efficient path.

3. Finally, the router allows networks with different architectures to communicate. For example, a router can be used to connect an Ethernet network with an DSL network or an Ethernet network with a Serial network such as a T1 circuit, or a Token Ring network to an ISDN line.

A switch is a simpler device (for this discussion). A switch tracks the MAC addresses (addresses from the Network Cards), and directs traffic between two devices, so that only the two devices involved in the conversation see the traffic. It is important to note that communicating devices must use the same address range when using a switch - for example: Station 1 would use 192.168.61.50 and station 2 would use 192.168.61.51. If the two stations use different address ranges, communication will not occur between them.

You are correct that a switch is faster than a router, but the router has a much more complicated job to perform.

Good Luck

Back to Networks Forum
12 total posts (Page 1 of 2)   01 | 02   Next

Related Discussions

Related Forums