The SOHO Network

Definitions (for SOHO purposes)

SOHO: Small Office, Home Office

Router: An ethernet device that routes or transfers traffic from one Network to another. For SOHO purposes, typically your Network to the Internet.

Switch: An Ethernet device that connects devices via ethernet cables on a common Network.

Class-C: Private Class-C addresses are used in small local area Networks (LANs).  The range of networks is 192.168.0.1 through 192.168.254.1. For SOHO purposes, the third set of numbers makes the network unique (255 unique networks, 0-254).

LAN: Local Area Network. This is your Network. The LAN has 255 uniques addresses defined by the last set of numbers in the IP address, 1-255. 255 is reserved and so there are 254 usable addresses on a SOHO LAN.

General

Definitions and information here is limited to that applicable to the SOHO Class-C Private Network. Networking is a complicated subject but it does not have to be complicated for the SOHO.  

The IP Address

The IP (Internet Protocol) address (Version 4) consists of four groups of 3 digit numbers separated by a period commonly spoken as “dot”. The IP address 192.168.0.1 would be spoken 192 dot 168 dot 0 dot 1. There are rules and limits to the numbers used – this is outside the scope of this paper.

Private Class C Address Space

SOHO routers have a default configuration that always has a Class C address typically starting 192.168.X.1 where “X” is typically “0” or “1”. “X” can be any number between 0 and 254. Using the default is fine.

For the purpose of this paper, 192.168.0.1 is assumed. The router therefore creates a SOHO Network addressing scheme of 192.168.0.1 through 192.168.0.255.  

To do this, what is called a “subnet mask” is used. The subnet-mask can be shown as 255.255.255.0 or 192.168.0.1/24 (for the example network). Never change the default subnet-mask unless you know what you are doing.

By default, the Router has address 192.168.0.1 and 192.168.0.255 is reserved. There are therefore 253 more useable addresses.

Rules

1. Each address on your network from dot-1 to dot-254 must be unique. No duplicates are allowed.
2. If an address is not in the example range of 192.168.0.1 thru 254, it is not on the example network and it is not accessible from the example network.
3. A static (fixed) IP address to a device on your network should not be in the DHCP range.

DHCP and Organization for Your Network

DHCP is an acronym for “Router Hands Out IP Addresses”.(1) The range of DHCP addresses handed out by a router is typically defaulted to something like dot-100 to dot-200. It is configurable in your Router.

DHCP is for temporary and portable devices that are not permanently attached to your network. Devices that are permanently attached to your Network should have a static (fixed) IP address assigned. This is done on the device – desktop computers, servers, switches, printers, wireless access points, etc should all have a static IP address.

Address space should be organized. Assuming the DHCP range above, Static IP addresses could be assigned anywhere between dot-2 and dot-99 and between dot-201 and dot-254.

Consider this for organization:

192.168.0.1: Router

192.168.0.21 to 29: Switches (switch 1 thru 9)

192.168.0.30 to 69: Desktop computers

192.168.0.70 to 79: Servers

192.168.0.100 to 200: DHCP for temporary devices

192.168.0.210 to 219: Printers

192.168.0.240 to 249: Wireless Access Points

Organize any way you like but organize and document.

The reasons for static IP addressing is twofold.

1. Network monitoring, troubleshooting, and management
2. Port Forwarding: Occasionally, a device needs to accessible from outside of your network. To do this, a “hole” is placed in the router with access to a specific IP address. This is done with what is called a port-number. Duck-Duck-Go is your friend.

Summary and Recommendations

1. Buy good equipment.
2. Use managed switches and routers so you can see network traffic and troubleshoot when necessary.
3. Assign static IP addresses to everything always attached to your network.
4. Only use DHCP for guests, temporary devices (such as laptops), and portable devices.
5. Document your network.
6. Keep it simple
7. Networking is easy if you understand the basics.
8. Don’t overthink a simple network.

(1) Humor