Network protocols

EDNS IPv4 subnet option

Generate an IPv4 Client Subnet option with host bits cleared.

Your inputs

Start with an example

Example result

Encode family 1, source prefix and query scope zero. Keep ceil(prefix/8) address bytes and clear unused low bits in the last byte.

192.0.2.129/24 sends address bytes C0 00 02, without the host octet.

Option bytes include code and length, but no OPT record or DNS message. This does not send a query or infer your IP address.