IP Addressing

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IP Addressing[edit | edit source]

When it comes to your homelab, IP addressing is important. There are a few points to consider before settling on an IP addressing scheme. Keep in mind that changing IPs or mixing and matching IP schemes is not recommended and can be difficult.

Picking a Supernet[edit | edit source]

First things first, you want to pick a supernet. Typically, this will be one of the three RFC 1918 private address ranges. I suggest using 10.0.0.0/8 because this gives you well over 16 million IPs to play with - which comes in very handy when implementing VLANs and avoiding overlaps.

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[edit | edit source]

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. Although this is rare, you can occasionally run into problems.