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)