Specifications
Distribution Layer April 2014
69
eigrp router-id [ip address of loopback 0]
eigrp stub summary
nsf
exit-address-family
Cisco Catalyst 6500 Series Switches do not require the ip routing command because it is enabled by default on
that platform.
Option 2: Conīgure OSPF unicast routing
Open Shortest Path First (OSPF) can be used instead of EIGRP for networks where OSPF is required for
compatibility. If you configured EIGRP in the previous procedure, you can skip this option.
Step 1: Enable OSPF for the IP address space that the network will be using. If needed for your network, you
can enter multiple network statements. Enable all routed links to be passive by default. The Loopback 0 IP
address is used for the OSPF router ID to ensure maximum resiliency. Each distribution gets a unique non-zero
area number, which is configured as a totally stubby area to optimize performance. An OSPF totally stubby area
only has a single default route out to the rest of the network, which is the case for a distribution switch.
ip routing
!
router ospf 100
router-id [IP address of loopback 0]
nsf
area [unique area number] stub no-summary
passive-interface default
network 10.4.0.0 0.0.15.255 area [unique area number]
network 10.4.40.0 0.0.0.255 area 0
Cisco Catalyst 6800 and 6500 Series Switches do not require the ip routing command because it is enabled by
default on that platform.
Procedure 5 Configure IP Multicast routing
IP Multicast allows a single IP data stream to be replicated by the infrastructure (that is, routers and switches) and
sent from a single source to multiple receivers. Using IP Multicast is much more efficient than multiple individual
unicast streams or a broadcast stream that would propagate everywhere. IP Telephony Music on Hold and IP
Video Broadcast Streaming are two examples of IP Multicast applications.
To receive a particular IP Multicast data stream, end hosts must join a multicast group by sending an Internet
Group Management Protocol (IGMP) message to their local multicast router. In a traditional IP Multicast design,
the local router consults another router in the network that is acting as a Rendezvous Point (RP) to map the
receivers to active sources so they can join their streams.
The RP is a control plane operation that should be placed in the core of the network or close to the IP Multicast
sources on a pair of Layer 3 switches or routers. IP Multicast routing begins at the distribution layer if the access
layer is Layer 2 and provides connectivity to the IP Multicast RP. In designs without a core layer, the distribution
layer will perform the RP function.