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V-216723

CAT II (Medium)

The Cisco multicast Rendezvous Point (RP) must be configured to rate limit the number of Protocol Independent Multicast (PIM) Register messages.

Rule ID

SV-216723r855829_rule

STIG

Cisco IOS XE Router RTR Security Technical Implementation Guide

Version

V3R5

CCIs

CCI-002385

Discussion

When a new source starts transmitting in a PIM Sparse Mode network, the DR will encapsulate the multicast packets into register messages and forward them to the RP using unicast. This process can be taxing on the CPU for both the DR and the RP if the source is running at a high data rate and there are many new sources starting at the same time. This scenario can potentially occur immediately after a network failover. The rate limit for the number of register messages should be set to a relatively low value based on the known number of multicast sources within the multicast domain.

Check Content

Review the configuration of the RP to verify that it is rate limiting the number of PIM register messages.

ip pim rp-address 10.2.2.2
ip pim register-rate-limit nn

If the RP is not limiting PIM register messages, this is a finding.

Fix Text

Configure the RP to rate limit the number of multicast register messages.

R2(config)#ip pim register-rate-limit nn