IP Addressing
IP Addressing
When it comes to your homelab, IP addressing is important. There are a few points to consider before settling on an IP addressing scheme.
Picking a Supernet
First things first, you want to pick a supernet. Typically, this will be one of the three RFC 1918
| RFC1918 name | IP address range | Number of addresses | Largest CIDR block (subnet mask) | Host ID size | Mask bits | Classful descriptionTemplate:Refn |
|---|---|---|---|---|---|---|
| 24-bit block | 10.0.0.0 – 10.255.255.255 | Template:Gaps | 10.0.0.0/8 (255.0.0.0) | 24 bits | 8 bits | single class A network |
| 20-bit block | 172.16.0.0 – 172.31.255.255 | Template:Gaps | 172.16.0.0/12 (255.240.0.0) | 20 bits | 12 bits | 16 contiguous class B networks |
| 16-bit block | 192.168.0.0 – 192.168.255.255 | Template:Gaps | 192.168.0.0/16 (255.255.0.0) | 16 bits | 16 bits | 256 contiguous class C networks |
Avoiding 192.168.0.0/16
I strongly recommend avoiding the 192.168.0.0/16 range of IPs due to backward compatibility issues. The reason is that some older networking devices or software may not recognize classless networking. While you can do 192.168.0.0/25, this may not make some legacy devices happy. Usually with classful, you can go smaller, not larger.