how important is Multicast with sccm? RRS feed

  • Question

  • Hi

    We have about 7,000 computers onsite, I am just curious how many of you that use Configuration Manager, have multicast enabled and are using it successfully in a lab environment? for example in this scenario, a lab of 50 pc's do you multicast, or unicast?

    Tuesday, June 18, 2013 10:30 PM


  • The benefit of multicast is that in can reduce the impact on network bandwidth utilization while laying down an image on a large number of machines simultaneously.


    In order to achieve this benefit, you're network equipment must be configured to support this (which is completely out of scope to ConfigMgr). Unfortunately, for a lot of organizations, it is rather difficult for them to get their firewalls and routers/switches configured to allow multicasting.  Some of these steps include:

    • IGMP Snooping on all subnets
    • Multicast routing on L3 switches/routers (If multicasting across subnets)
    • PIM on L3 switches/routers (If multicasting across subnets)
    • Firewall exceptions for the defined multicast ports from the multicast addresses


    It is important to realize that the network bandwidth savings do not equate to a speed increase.  In fact, it will add a significant amount of overhead (and CPU utilization on your switch) which makes the process take longer.  It also adds a lot of complexity and opprotunities for failures.


    If you don't have a network team that can figure these things out, you can consider putting a distribution point in the same building as the lab and just unicasting from it.  If that isn't an option, you can stagger your image deployments to keep the network utilization manageable.


    I hope that helps,



    Nash Pherson, Senior Systems Consultant
    Now Micro - My Blog Posts
    <-- If this post was helpful, please click "Vote as Helpful".

    • Edited by NPherson Wednesday, June 19, 2013 1:59 AM typo
    • Marked as answer by clivebuckwheat Wednesday, June 19, 2013 1:58 PM
    Wednesday, June 19, 2013 1:58 AM