Networking Tetris — VLSM Block Boundary Grid

Enter a base network (IPv4 or IPv6 CIDR). The grid represents the whole base block, split into 64 “pixels”. Drag a block from Block selection onto the grid, or tap a block and then tap the grid on mobile. Placement snaps to valid VLSM boundaries and blocks cannot overlap.

Base network (CIDR)

Examples: 10.0.0.0/20, 192.168.1.0/24, 2001:db8::/48, fd00:1234::/64

Base: —

Pixel size: —

Drop anywhere on a cell. The tool snaps to the correct block boundary automatically.

Assigned blocks

Placed blocks appear here. Remove any block to free that space in the grid.

Label	CIDR	Px	Addresses	Usable	Network ID	Last