What it does
mcjoin is a small multicast test tool with sender and receiver roles and support for any-source and source-specific groups.
Choose a sending endpoint or joining receiver, then specify any-source or source-specific groups and the intended interface. mcjoin can handle multiple IPv4 or IPv6 groups; a specified source must use the same address family as its group. The sender needs an address configured on the outgoing interface. Joining a group successfully does not by itself prove delivery: the README explains how reverse-path routing or filtering can prevent received traffic. Linux, FreeBSD, macOS and Illumos are listed, while NetBSD and OpenBSD lack the required multicast API. Use separate send/receive observations to distinguish membership from forwarding.
Strengths
- ASM and SSM tests for multiple groups