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)