[TriLUG] error: permission denied on key 'net.ipv4.conf.eth0.mc_forwarding'

[Ralph Blach]

When ever I issue the command

  sysctl -w net.ipv4.conf.eth0.mc_forwarding=1

I get the following error

error: permission denied on key 'net.ipv4.conf.eth0.mc_forwarding'

How do I get around this error.  I need to be able to turn on forwarding.

Chip