IP Multicast Switch Port Extender Systems

In this section:

1. Switch Port Extender and IP Multicast
   In a Campus Fabric, or Switch Port Extender (SPX), configuration, forwarding decisions always occur in the Control Bridge (CB) units, even for traffic that ingresses on a Port Extender (PE) port.
2. IP Multicast Hardware Entry Optimization
   IP multicast (IPMC) entries are used to replicate Layer 3 multicast packets in the hardware. Each multicast route entry points to the IPMC entry to replicate this flow at the hardware level.