All things related to multicast

[Leonard Giuliano <>]

Keep in mind that SAP is useful for some apps like SDR, VLC, IPTV, etc.  
Policing the entire SAP group to 1Mbps just makes it easier to DOS SAP- 
now you only need to send 1Mbps of mcast data at the SAP group and no good 
SAP packets will get through either, effectively taking down the entire 
SAP service.

Routers have no problems with high SAP data rates.  They will happily 
forward them with no problems.  The problem happens when you tell the 
routers to listen to these SAP announcements.

Listening to SAP messages was once a nice, quick and easy way to see if 
mcast was working.  The benefit may not be worth the risk anymore.  May 
want to think about simply turning off SAP listening on the routers 
(delete protocols sap / no sdr listen).

This will still forward the SAP announcements to the intended receiving 
hosts, it just won't cache these messages on the routers.


-Lenny