Cisco Systems 78-11741-02 manual Border Router Configuration Example, IPC-450

Configuring IP Multicast Routing

IP Multicast Configuration Examples

ip pim sparse-dense-mode

!

router ospf 1

network 172.21.24.8 0.0.0.7 area 1 network 172.21.24.16 0.0.0.7 area 1

!

ip pim bsr-candidate Ethernet2 30 10

ip pim rp-candidate Ethernet2 group-list 5 access-list 5 permit 239.255.2.0 0.0.0.255

Border Router Configuration Example

The following example shows how to configure a border router in a PIM-SM domain on Ethernet interface 1. The ip pim bsr-borderinterface configuration command will prevent BSR messages from being sent or received through the interface. The ip multicast boundary interface configuration command and access list 1 will prevent Auto-RP messages from being sent or received through the interface.

version 12.0

!

ip multicast-routing

!

interface Ethernet0

ip address 171.69.62.35 255.255.255.240

!

interface Ethernet1

ip address 172.21.24.18 255.255.255.248 ip pim sparse-dense-mode

ip pim bsr-border

ip multicast boundary 1

!

!Access list to deny Auto-RP (224.0.1.39, 224.0.1.40) and

!all administrately scoped multicast groups (239.X.X.X) access-list 1 deny 239.0.0.0 0.255.255.255 access-list 1 deny 224.0.1.39

access-list 1 deny 224.0.1.40

access-list 1 permit 224.0.0.0 15.255.255.255

RFC 2362 Interoperable Candidate RP Example

When Cisco and non-Cisco routers are being operated in a single PIM domain with PIM Version 2 BSR, care must be taken when configuring candidate RPs because the Cisco IOS implementation of the BSR RP selection is not fully compatible with RFC 2362.

RFC 2362 specifies that the BSR RP be selected as follows (RFC 2362, 3.7):

Step 1 Select the candidate RP with the highest priority (lowest configured priority value).

Step 2 If there is a tie in the priority level, select the candidate RP with the highest hash function value.

Step 3 If there is a tie in the hash function value, select the candidate RP with the highest IP address.

Cisco routers always select the candidate RP based on the longest match on the announced group address prefix before selecting an RP based on priority, hash function, or IP address.

Cisco IOS IP Configuration Guide

IPC-450