I intend to setup a small office network. Based on the article below, it mention that I should use switch for all the LAN points for my cubicles, but I am puzzled.

How does switch issues IP address for each of the machine plug-in? since switch does not act like router and do not provide DHCP service.

Building a Small Office Network: The Difference Between Switches and Routers

When building a small office network, the two most essential pieces of equipment you will need are switches and routers. Though they look similar, the two devices perform different functions in a network.

Switches connect multiple devices (computers, printers, servers) on the same network within a building or campus. A switch enables connected devices to share information and talk to each other. Building a small office network isn’t possible without switches to tie devices together.
Routers tie multiple networks together. When building a small office network, you’ll need one or more routers. A router connects your networked computers to the Internet. This enables all connected computers to share one single Internet connection. A router acts as a dispatcher, choosing the best route for your information to travel. It connects your business to the world, protects information from security threats, and can even decide which computers get priority over others.



Switches don't issue IP addresses to devices.

Either all devices have a statically configured IP address, or you use a DHCP server that will assign the IP automatically. (or a mix of it, generally servers and specific devices like printers have static IP addresses while users computer have DHCP assigned IP)

Many routers include a DHCP server feature, but you don't have to use them. A server, be it Windows, Linux, Netware, Solaris, etc.. can act as the DHCP server.

The switches allow the different devices in the network to communicate, this include the communication between the devices and the DHCP server.

Some high-end (read expensive) switches have routing capabilities and even DHCP services but this is really different functions embedded in a single box, and the DHCP service is still unrelated to the switching function.

  • If I am connected to the switch, how/where am I getting the IP addresses from, since switch does not have the ability to assign IP? – ilovetolearn Mar 30 '17 at 12:36
  • If you have a DHCP server configured in the network, then the machine send a DHCP request, the server respond and give an IP address. If you don't have a DHCP server, most devices will use a self assigned IP address, also called APIPA IP , as defined in RFC3927 but in real life you never build a network on APIPA. In short: you have to setup a DHCP server – JFL Mar 30 '17 at 12:40
  • you mean, when I am connected to the switch, the request for an IP will be sent via the switch to the DHCP server? – ilovetolearn Mar 30 '17 at 13:23
  • Yes, but you have to understand the concept of Layers in networking. DHCP act at the application layer while the switch only care about the Network Interface Layer. The switch will happily transfer whatever information the computers sends. It doesn't care if it is a DHCP request or a request to see a web page, it is meaningless to the switch. And the DHCP process don't care if the request goes through an ethernet switch or another type of network. Think about how you use your phone and are able to call anyone without knowing the details of the phone network. – JFL Mar 30 '17 at 13:54
  • 1
    @youcanlearnanything, DHCP requests are broadcasts, which means that they are sent to every host on the network. Switches will send broadcasts to every switch interface (other than the one on which it enters the switch). – Ron Maupin Mar 30 '17 at 13:57

You have to sit and define the following * What IP address Class and Range am going to use * You have to define the Address Pool that is going to be used * Also you have set aside or reserve IP addresses for Printers and Servers

I am not that much detailed but even though it is small today you have to think your small network should be able to grow scale, that needs good documentation.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.