Designing the Home Network

Before you begin your design, you need to make sure that you've answered all the questions I referred to in earlier posts.

This design is based on the following assumptions:

• The network will use a single tier hub-and-spoke architecture
• It will be based on a mixture of hard-wired and wireless spokes and will use the Internet Protocol Suite
• It will connect to the Internet using Cable
• The Internet will be disconnected when the house is unoccupied
• There will be three 100Mbps wired nodes downstairs, and three upstairs
• All Wi-Fi connections will use IEEE802.11g
• There will be:
• at least one Wi-Fi connected laptop PC and one hard-wired PC
• a hard-wired networked All-in-1 printer/scanner/copier
• a Wi-Fi connected portable printer
• at least one Wi-Fi connected Voice-over-IP (VoIP) capable phone that will access Skype
• a Wi-Fi connected smart meter and games console
• Guest connections will be permitted, and the laptop, portable printer and games console may be connected to other networks

These assumptions imply the following design decisions:

• Use a domestic class switch-router which incorporates the following:
• A router
• A 6-port Ethernet switch
• A Wi-Fi infrastructure access point
• A firewall, 
• A DNS server/relay
• A DHCP server
• A NAT server
• Have a dynamic public IP address assigned by the cable ISP
• Decide on a location for the router as near the center of the property as is compatible with access to the cable terminal
• Select a private IP address range.  This is selected for this design to be 192.168.0.0/24 (i.e a single block of 256 addresses from 192.168.0.0 to 192.168.0.255)
• Allocate a DHCP block from within the IP range.  This is selected for this design to be 192.168.0.100 to 192.168.0.200 (a single block of 100 addresses)
•  Allocate an IP address for the router itself from your private IP range. This is selected for this design to be 192.168.0.254.  Some router make this selection for you, and often choose the first address in the subnet (in this case this would be 192.168.0.1).  The actual address chosen is not important, but to make it easy to remember and to help to trace faults later, I suggest either the first or last available address in your chosen range (.1 or .254 - remember, the .0 and .255 addresses cannot be used as device addresses)
• Allocate addresses for your permanently-connected devices (your desktop PC, printer etc.)  Again, to make it easy to remember, I tend to allocate peripherals such as printers, smart meters etc. addresses next to that for the router, and addresses for PCs from the far end of the address range so, for instance, for this design I would select:
• 192.168.0.253 for the networked All-in-1 printer
• .252 for the smart meter (assuming that this can be altered - usually it can!)
• .251 for the VoIP phone
• .1 for the desktop PC
• All the other devices (the laptop, portable printer, games console) will get their IP addresses automatically 

 And that's it.  Your network is designed.

However, we need to consider the implications of what we've designed.

1. The Pros

• It is simple and fairly cheap.  
• All the key functionality is contained within a single device (the Internet Access Router)

1. The Cons

• If the Internet Access Router fails, your network is toast...
• There is no security once a device is connected to your network.  They will have unrestricted access to the Internet and any of your devices that don't have their own built-in security (hence, always use passwords on PCs...)