Multicast

Multicast enables the SCCM server to deploy operating system images to multiple computers at once, cutting the amount of time it takes to image large batches of computers at once as opposed to unicast.

Multicast should be enabled each time a computer lab is re-imaged. It should be disabled again afterwards to prevent unnecessary broadcast traffic from traversing VLANs.

Multicast needs to be enabled on the server VLAN and on any VLANs containing hosts that will be imaged. Multicast only needs to be enabled on the switches between the SCCM server and computers receiving the image.

See http://whp-hou9.cold.extweb.hp.com/pub/networking/software/8200zl-RoutingMulticast-Sept2007-59918586.pdf for more information.

Enable

To enable multicast you must first enable it on the global level for the switch, and then enable it for each VLAN that is needed. Then, on the core switch only, make the switch the querier for each VLAN. Finally, on the core switch only, enable pim-dense both globally and on each VLAN.

Core switch only: Enable multicast globally:

ip multicast-routing
router pim

All switches along the path: Enable multicast on the VLAN level (repeat for each VLAN needed):

vlan <VLAN ID> ip igmp

Core switch only: Make the switch the querier and enable pim-dense on the VLAN level (repeat for each VLAN needed):

vlan <VLAN ID> ip igmp querier
vlan <VLAN ID> ip pim-dense
exit

View the multicast configuration by running the following commands:

show ip igmp
show ip igmp config
show ip igmp vlan <VLAN ID>

Make sure to write memory to save the config.

Disable

Multicast should be disabled when not imaging the labs.

Core switch only: Disable multicast at the switch's global level:

no ip multicast-routing
no router pim

All switches along the path: Disable multicast on the VLAN level (repeat for each VLAN needed):

no vlan <VLAN ID> ip igmp

Core switch only: Disable querier and pim-dense on the VLAN level (repeat for each VLAN needed):

vlan <VLAN ID> ip igmp querier
vlan <VLAN ID> no ip pim-dense
exit

Make sure to write memory to save the config.

  • switches/multicast.txt
  • Last modified: 2019/03/15 18:21
  • by ericclaus