Cisco Cisco IOS Software Release 12.0(19)S

Traditional IP communication allows a host to send packets to a single host (unicast transmission) or to 
all hosts (broadcast transmission). IP multicast provides a third scheme, allowing a host to send packets 
to a subset of all hosts (group transmission). These hosts are known as group members.

ISE line cards conduct IPv4 multicast in software.

See 

 for additional information on feature capability and configuration. 

The ISE line cards support the following multicast features:

Access Control Lists (ACLs) on multicast flows (see also 

).

Identify IP multicast flows according to IP multicast addresses. 

Dynamic Registration using Internet Group Management Protocol (IGMP):
IGMP is used between hosts on a LAN and the router(s) on that LAN to track of which multicast 
groups the hosts are members.

Reverse Path Forwarding (RPF): 
RPF is an algorithm used for forwarding multicast datagrams.

Protocol-Independent Multicast (PIM) sparse mode (SM) and dense mode (DM): 
PIM is used between routers so that they can track which multicast packets to forward to each other 
and to their directly connected LANs. In populating the multicast routing table, dense-mode 
interfaces are always added to the table. Sparse-mode interfaces are added to the table only when 
periodic “Join” messages are received from downstream routers, or when there is a directly 
connected member on the interface.

Auto-RP (Rendezvous Point): this feature automates the distribution of group-to-RP mappings in a 
PIM network. 

Multicast Source Discovery Protocol:
MSDP is a mechanism to connect multiple PIM sparse-mode (SM) domains. 

Multiprotocol BGP Extensions for IP Multicast:
MBGP is an enhanced BGP that carries IP multicast routes. BGP carries two sets of routes, one set 
for unicast routing and one set for multicast routing. The routes associated with multicast routing 
are used by the Protocol Independent Multicast (PIM) to build data distribution trees. 

The ISE line cards support Extended ACLs for:

Incoming and outgoing traffic

Subinterfaces

Thousands of ACL and xACL entries

Access Control Lists (ACLs), sometimes called filters, provide a tool for network control and security, 
allowing you to filter packet flow into or out of switch router interfaces. Network operators can use ACLs 
to limit network traffic, and to restrict network use by certain users or devices. Standard IP ACLs use 
source addresses for matching operations. Extended IP ACLs use source and destination addresses for 
matching operations, as well as optional protocol type information for finer granularity of control. ACLs 
can be applied to an interface as either an inbound ACL or an outbound ACL.