Reference Guide

Multicast Features | 583
• IPv4 Multicast Policies
• Permit or deny PIM Join/Prune messages on an interface using an extended IP access list. Use the
command ip pim join-filter to prevent the PIM SM router from creating state based on multicast
source and/or group.
IPv4 Multicast Policies
• Limit the Number of Multicast Routes
• Prevent a Host from Joining a Group
• Rate Limit IGMP Join Requests
• Prevent a PIM Router from Forming an Adjacency
• Prevent a Source from Registering with the RP
• Prevent a PIM Router from Processing a Join
Limit the Number of Multicast Routes
When the limit is reached, FTOS does not process any IGMP joins to PIM—though it still processes leave
messages—until the number of entries decreases below 95% of the limit. When the limit falls below 95%
after hitting the maximum, the system begins relearning route entries through IGMP, and MSDP.
• If the limit is increased after it is reached, join subsequent join requests are accepted. In this case, you
must increase the limit by at least 10% for IGMP to resume.
• If the limit is decreased after it is reached, FTOS does not clear the existing sessions. Entries are
cleared upon a timeout (you may also clear entries using
clear ip mroute).
When the multicast route limit is reached, FTOS displays Message 1.
Task Command Syntax Command Mode
Limit the total number of multicast routes on the system. ip multicast-limit
Range: 1-16000
Default: 4000
CONFIGURATION
Note: FTOS waits at least 30 seconds between stopping and starting IGMP join processing. You may
experience this delay when manipulating the limit after it is reached.
Message 1 Multicast Route Limit Error
3w1d13h: %RPM0-P:RP2 %PIM-3-PIM_TIB_LIMIT: PIM TIB limit reached. No new routes will be
learnt until TIB level falls below low watermark.
3w1d13h: %RPM0-P:RP2 %PIM-3-PIM_TIB_LIMIT: PIM TIB below low watermark. Route learning will
begin.