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Software Configuration Guide—Release 12.2(25)SG
OL-7659-03
Chapter1 Product Overview
Management Features
•Protocol Independent Multicast (PIM)—PIM is protocol-independent because it can leverage
whichever unicast routing protocol is used to populate the unicast routing table, including EIGRP,
OSPF, BGP, or static route. PIM also uses a unicast routing table to perform the Reverse Path
Forwarding (RPF) check function instead of building a completely independent multicast routing
table.
For information on configuring multicast services, see Chapter24, “Understanding and Configur ing
IP Multicast.”

Policy-Based Routing

Traditional IP forwarding decisions are based purely on the destination IP address of the packet being
forwarded. Policy Based Routing (PBR) enables forwarding based upon other i nformation associated
with a packet, such as the source interface, IP source address, Layer 4 ports, and so on. This feature
allows network managers more flexibility in how they configure and design their networks.
For more information on policy-based routing, see Chapter 25, “Configuring Pol icy-Based Routing.”

Unidirectional Link Routing

Unidirectional link routing (UDLR) provides a way to forward multicast packets over a physical
unidirectional interface (such as a satellite link of high bandwidth) to stub networks that have a back
channel.
For information on configuring unidirectional link routing, refer to the chapter “Configuring
Unidirectional Link Routing” in the Cisco IP and IP Routing Configuration Guide.

VRF-lite

VPN routing and forwarding (VRF-lite) is an extension of IP routing that provides multiple routing instances.
Along with BGP, it enables the creation of a Layer 3 VPN service by keeping separate IP routing and
forwarding tables for each VPN customer. VRF-lite uses input interfaces to distinguish routes for different
VPNs. It forms virtual packet-forwarding tables by associating one or more Layer 3 interfaces with each VRF,
allowing the creation of multiple Layer 3 VPNs on a single switch. Interfaces in a VRF could be either
physical, such as an Ethernet port, or logical, such as a VLAN switch virtual interface (SVI). However,
interfaces cannot belong to more than one VRF at any time.
For information on VRF-lite, see Chapter26, “Configuring VRF-lite.”
Management Features
The Catalyst 4500 series switch offers network management and contro l through the CLI or through
alternative access methods, such as SNMP. The switch software supports these network management
features:
•Cisco Network Assistant and Embedded CiscoView, page 1-10
•Dynamic Host Control Protocol, page 1-10
•Forced 10/100 Autonegotiation, page 1-10
•Intelligent Power Management, page 1-10