NAME

       mcfirst - check if you can receive IPv4/IPv6 multicast

SYNOPSIS

       mcfirst [ -46vr ] [ -I interface ] [ -c count ] [ -t time ] [ source ] group port

DESCRIPTION

       mcfirst can be used to check whether one can receive multicast packets from a host. The host may send any
       type  of  multicast  packets,  any  application,  IPv4  or IPv6, ASM or SSM.  mcfirst joins the specified
       (source) and group, and listens to the specified port.  mcfirst will  by  default  exit  when  the  first
       packet is received, and print how long it waited.

OPTIONS

       The options are as follows.

       -4     Force IPv4

       -6     Force IPv6

       -v     Print version

       -r     Print rate information only

       -I interface
              Interface to join on

       -c count
              Stop after receiving count packets. Default is 1 unless time limit is specified

       -t time
              Exit  after  time  seconds.  Default is to exit after the first packet. If both count and time are
              specified, mcfirst will exit as soon as one of them is satisfied.

SEE ALSO

       ssmping(1) a tool for checking whether can receive SSM.

       dbeacon(1) a distributed beacon multicast implementation.

BUGS

       Please report them to Stig Venaas <venaas@uninett.no>, the author of this tool.

HISTORY

       mcfirst was developed by Stig Venaas during the early days of the m6bone, the IPv6 multicast backbone.

                                                  User Manuals                                        mcfirst(1)