IPv4 Subnet Planner
Carve a parent network into VLSM allocations, check for overlaps, and export the plan.
parent network
subnet allocations
| Label | CIDR | Network address | Size (IPs) | VLAN | Description | Color | Actions |
|---|
IPv4 reserved address reference
Private Addresses (RFC 1918)
10.0.0.0/8
Class A private network - 16,777,216 addresses
10.0.0.0 - 10.255.255.255
172.16.0.0/12
Class B private network - 1,048,576 addresses
172.16.0.0 - 172.31.255.255
192.168.0.0/16
Class C private network - 65,536 addresses
192.168.0.0 - 192.168.255.255
Special-Purpose Addresses
127.0.0.0/8
Loopback addresses (localhost)
RFC 1122 - Typically 127.0.0.1
169.254.0.0/16
Link-Local / APIPA (Automatic Private IP Addressing)
RFC 3927 - Used when DHCP unavailable
100.64.0.0/10
Carrier-Grade NAT (CGN)
RFC 6598 - Shared address space for ISPs
Multicast & Broadcast
224.0.0.0/4
Multicast addresses (former Class D)
224.0.0.0 - 239.255.255.255
255.255.255.255/32
Limited broadcast address
RFC 919 - Broadcast to local subnet
Documentation & Testing
192.0.2.0/24
Documentation (TEST-NET-1)
RFC 5737 - Examples and documentation
198.51.100.0/24
Documentation (TEST-NET-2)
RFC 5737 - Examples and documentation
203.0.113.0/24
Documentation (TEST-NET-3)
RFC 5737 - Examples and documentation
198.18.0.0/15
Benchmarking and testing
RFC 2544 - Network performance testing
Reserved & Future Use
0.0.0.0/8
Current network (only valid as source)
RFC 1122 - This network
240.0.0.0/4
Reserved for future use (former Class E)
RFC 1112 - Experimental