/30 subnet
A /30 prefix equals subnet mask 255.255.255.252 and wildcard 0.0.0.3. It holds 4 addresses, 2 of them usable by hosts.
/30
- Subnet mask
- 255.255.255.252
- Wildcard mask
- 0.0.0.3
- Binary mask
- 11111111.11111111.11111111.11111100
- Total addresses
- 4
- Usable hosts
- 2
- Example network
- 10.0.0.0/30
- Example range
- 10.0.0.0 – 10.0.0.3
- How many fit
- 4,194,304 × /30 in a /8, 16,384 × /30 in a /16, 64 × /30 in a /24
The classic choice for point-to-point links: two addresses for two routers. /31 is now often used instead.