Hvad er Subnetting?
Subnetting er processen med at opdele et netværk i to eller flere mindre netværk. Det forbedrer trafikflow, sikkerhed og forenkler netværksadministration.
Almindelig CIDR-notation
- /32: Enkelt IP-adresse Single IP address
- /30: Punkt-til-punkt link (2 brugbare hosts) Point-to-point link (2 usable hosts)
- /24: Standard lille netværk (254 brugbare hosts) Standard small network (254 usable
hosts)
- /16: Stort virksomhedsnetværk (65.534 brugbare hosts) Large corporate network (65,534 usable
hosts)
- /8: Meget stort netværk (16,7 mio. brugbare hosts) Very large network (16.7M usable hosts)
Computes network addresses, broadcast addresses, usable host ranges, and CIDR notation for IP subnets. Essential for network planning.
Key Facts
- /24 subnet has 254 usable IPs
- Private ranges: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16
- Subnetting introduced in 1985 (RFC 950)
- CIDR replaced classful networking in 1993
Frequently Asked Questions
What is a subnet?
A logical division of an IP network into smaller segments for security, performance, and efficient IP usage.
What does /24 mean?
First 24 bits are network portion, 8 bits for hosts = 254 usable addresses.
How to calculate hosts?
Formula: 2^(32-prefix) - 2. For /24: 2^8 - 2 = 254 usable hosts.
Public vs private IP ranges?
Private (10.x, 172.16-31.x, 192.168.x) for internal use. Public IPs are globally unique for internet.