IPv4 multicast entry not added. Hardware L3 Table full. (Logged at most

  • 7 January 2014
  • 1 reply

Userlevel 4
Create Date: Aug 2 2013 7:17PM

What is that? I'm not using any sort of multicast networking that I am aware of. Why is the table getting full? Is igmp on by default? If I disable it will I break anything?

THanks, (from Jeremy_Homan)

1 reply

IGMP snooping enabled by default.
show iproute reserved-entries statistics - will give you more details about the utilization of L3 hardware table and L3 hash table.
show mcast cache summary - will give you the number of entries occupied in L3 hash - IPv4 Mcast table.
debug hal show ipv4mc also gives more details on this issue.
If you are running with vlans less than 1000, then following below options will reduce the IPv4 mcast entries in the table,
config igmp snooping filter per-vlan
config igmp snooping forwarding-mode group-vlan