Indeed was confusing to me as well, that's why I got it wrong (disabled is protect action from the router, see note below), here's more info:

� Filter Multicast � This feature blocks multicasting or the method of sending IP diagrams to a group of receivers in a single transmission. This option is set to Disabled by default. Select this option to enable filter multicasting.

NOTE: IP multicasting is widely used in enterprises, commercial stock exchanges and multimedia content delivery networks such as IPTV applications. If you do not use such applications, it is much advisable to keep this option disabled to protect your network from spoofing or Denial of Service (DoS) attacks.


on http://homekb.cisco.com/Cisco2/ukp....a6b436a4edc92576ba183b91f5c_KB_EN_v1.xml

Guido.

568.1 Processor, 562v3 MController, 596 DVD Player, 504 Tuner, MC200, MS600, 218, 210, Roon