Cisco multicast configuration in best practice

Here is sample configuration of Cisco multicast configuration in best practice

 

To enable multicast routing

Cisco-Devices(config)# ip multicast-routing
 

To enable multicast on interfaces

Cisco-Devices(config)# interfce fa0/0
Cisco-Devices(config-if)# ip pim dense-mode

 

To show a multicast routing table

Cisco-Devices# sh ip mroute
IP Multicast Routing Table
Flags: D – Dense, S – Sparse, B – Bidir Group, s – SSM Group, C – Connected,
       L – Local, P – Pruned, R – RP-bit set, F – Register flag,
       T – SPT-bit set, J – Join SPT, M – MSDP created entry,
       X – Proxy Join Timer Running, A – Candidate for MSDP Advertisement,
       U – URD, I – Received Source Specific Host Report,
       Z – Multicast Tunnel, z – MDT-data group sender,
       Y – Joined MDT-data group, y – Sending to MDT-data group
Outgoing interface flags: H – Hardware switched, A – Assert winner
 Timers: Uptime/Expires
 Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 224.0.1.40), 02:07:29/00:02:39, RP 0.0.0.0, flags: DCL
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    FastEthernet0/0, Forward/Dense, 02:07:29/00:00:00
 

* When PIM is enabled on an interface, IGMP is also enabled.
** The (224.0.1.40) is always created, once PIM is enabled on Cisco devices.

 

To show a IGMP status of the interface

 

Cisco-Devices# sh ip igmp interface fa0/0
FastEthernet0/0 is up, line protocol is up
  Internet address is 10.1.100.1/24
  IGMP is enabled on interface
  Current IGMP host version is 2  <——– It can be changed by “ip igmp version” CLI.
  Current IGMP router version is 2
  IGMP query interval is 60 seconds <—- To discover which multicast groups have members on the interface. It can be changed by ” ip igmp query-interval”
  IGMP querier timeout is 120 seconds <— It is twice of query interval.
  IGMP max query response time is 10 seconds
  Last member query count is 2
  Last member query response interval is 1000 ms
  Inbound IGMP access group is not set
  IGMP activity: 1 joins, 0 leaves
  Multicast routing is enabled on interface
  Multicast TTL threshold is 0
  Multicast designated router (DR) is 10.1.100.2
  IGMP querying router is 10.1.100.1 (this system)
  Multicast groups joined by this system (number of users):
      224.0.1.40(1)
 
 

* The querier is responsible for forwarding the multicast flow.
** IGMPv1 doesn’t have a querier election.