CIDR CIDR (Classless Inter-Domain Routing) tilldelar IP-adresser och dirigerar internettrafik via prefixnotation (/N).
Vanliga CIDR-subnätintervall
| CIDR-prefix | Subnätmask | Totalt adresser | Användbara värdar | Exempelintervall |
|---|---|---|---|---|
/32 |
255.255.255.255 |
1 | 1 | 192.168.1.1 (Enskild värd) |
/30 |
255.255.255.252 |
4 | 2 | 10.0.0.0 – 10.0.0.3 (Punkt-till-punkt-länk) |
/28 |
255.255.255.240 |
16 | 14 | 192.168.1.0 – 192.168.1.15 |
/26 |
255.255.255.192 |
64 | 62 | 192.168.1.0 – 192.168.1.63 |
/24 |
255.255.255.0 |
256 | 254 | 192.168.1.0 – 192.168.1.255 |
/20 |
255.255.240.0 |
4,096 | 4,094 | 172.16.0.0 – 172.16.15.255 |
/16 |
255.255.0.0 |
65,536 | 65,534 | 10.0.0.0 – 10.0.255.255 |
/8 |
255.0.0.0 |
16,777,216 | 16,777,214 | 10.0.0.0 – 10.255.255.255 |
/0 |
0.0.0.0 |
4,294,967,296 | All | 0.0.0.0/0 (Standardrutt / Hela internet) |
Privata IPv4-adressblock (RFC 1918)
- 24-bitars block (10.0.0.0/8): 10.0.0.0 – 10.255.255.255 (16,7M adresser)
- 20-bitars block (172.16.0.0/12): 172.16.0.0 – 172.31.255.255 (1M adresser)
- 16-bitars block (192.168.0.0/16): 192.168.0.0 – 192.168.255.255 (65 536 adresser)
- Loopback (127.0.0.0/8): 127.0.0.1 (Localhost)
- Link-Local (169.254.0.0/16): Tilldelas automatiskt om DHCP misslyckas