I created route for multicast with linuxconf which yielded:
any net 224.0.0.0 netmask 240.0.0.0 gw eth0
in /etc/sysconfig/static-routes.
This is the only route in this file. The route is not added
as there is an error in ifup-routes script.
Line 19 in script reads:
  if [ "$dev" = "$device" ]; then
This will  return false as in my case $device
has not been assigned yet. I guess this line should
be:
  if [ "$dev" = "$1" ]; then