Hi,
I am reading the Cisco Press CEF book and I see the following in relation to generic FIB entries.
224.0.0.0/4 drop— This entry drops packets destined to this reserved IP multicast address space when IP Multicast Routing is disabled. If IP Multicast Routing is enabled, the FIB entry will be reported as a punt adjacency. Note that CEF does not support the switching of multicast packets. By default, multicast packets are fast-switched through a router.
224.0.0.0/24 receive— The range of multicast IP addresses, 224.0.0.0 through 224.0.0.255, is reserved for the use of routing and discovery protocols. For example, Enhanced Interior Gateway Routing Protocol (EIGRP) transmits hello packets to multicast address 224.0.0.10 to maintain neighbor relationships. This FIB entry allows the router to receive and process packets destined to this IP address range.
It says the 224.0.0.0/24 would be reported as a PUNT if IP Multicast was enabled. However the 224.0.0.0/24 generic entry is reported as "Receive". They are both Multicast. I would have thought it the /24 would be a PUNT also as CEF does not process multicast packets?
Obviously missing something so if someone could help me understand it would be greatly appreciated.
Thanks
