IP multicast filters

IP multicast addresses occur in the range from 224.0.0.0 through 239.255.255.255 (which corresponds to the ethernet multicast address range of 01005e-000000 through 01005e-7fffff.) Where a switch has a static traffic/security filter configured with a "multicast" filter type and a "multicast address" in this range, the switch will use the static filter unless IGMP learns of a multicast group destination in this range. In this case, IGMP dynamically takes over the filtering function for the multicast destination addresses for as long as the IGMP group is active. If the IGMP group subsequently deactivates, the switch returns filtering control to the static filter.

Reserved addresses excluded from IP multicast filtering

Traffic to IP multicast groups in the IP address range of 224.0.0.0 to 224.0.0.255 will always be flooded because addresses in this range are "well known" or "reserved" addresses. Thus, if IP multicast is enabled, and there is an IP multicast group within the reserved address range, traffic to that group will be flooded instead of filtered by the switch.

Show IP PIM

Syntax

show ip pim neighbors

Show PIM protocol operational and configuration information.

neighbors

Show PIM neighbor information.

show ip pim

PIM Global Parameters
PIM Status                   : Enabled
State Refresh Interval (sec) : 60 
Join/Prune Interval (sec)    : 60
SPT Threshold                : Enabled  
Traps                        : none

show ip pim neighbors

Lists PIM neighbor information for all PIM neighbors connected to the routing switch.

neighbor	Show PIM neighbor information.
IP Address,	Lists the IP address of a neighbor multicast router.
VLAN,	Lists the VLAN through which the routing switch connects to the indicated neighbor.
Up Time,	Shows the elapsed time during which the neighbor has maintained a PIM route to the routing switch.
Expire Time,	Indicates how long before the router will age-out a PIM neighbor/adjacency relationship on the specified interface (VLAN.) When a neighbor/adjacency expires and that neighbor was the last one on the interface, multicast data and state refresh packets will no longer be sent out that interface. Receipt of a periodic PIM hello message from the neighboring PIM router resets this timer to the hold time value stored in the hello message. If the ip-addr is specified then detailed information for the specified neighbor is shown.

IM Neighbors
IP Address      VLAN Up Time (sec)      Expire Time (sec) 
 --------------- ---- ------------------ ------------------
20.1.1.2        20   193                83

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