4 Replies Latest reply on Sep 14, 2011 8:29 AM by MarXtar

    Questions on Targeted Multicasting

    Rookie

      A couple weeks ago I sent out a Policy Supported  Push to about 13,000 PCs.  These 13,000 PCs are found on about 1500+ different subnets. The push was about 150MB so I used Target Multicast.  The delivery method was set to 40 devices at a time, Targeted Multicast, 25%WAN and 75% Local.  This job has been running for literally a couple weeks.  I have been monitoring the results and I have developed a couple of questions from this.

       

      1. In the delivery methods used for this push, I noticed under Network Usage > Multicast limits the Maximum number of multicast domain representatives working simultaneously is set to 5.  Does this mean that even though 40 devices can recieve that push at a time that only 5 Multicast Reps are actually allowed to be pulling down the files?

       

      2. There are about 5000 devices in the Active state in the Scheduled task that have a Status of "Multicast failed, could not find a multicast domain representative".  I have not been able to find any documentation of what this error means specifically (though the error itself sheds a little light) and what will happen with these machines.  Will they wait their turn to pull down the job from the core directly since a Multicast rep was not found or will they just give up and eventually fail?

        • 1. Re: Questions on Targeted Multicasting
          Employee

          I would not use multicast to deliver this job.  Here is the best way to do it.  In your delivery method, set the following:

           

          1.  Under the bandwitch detection option select Limit remote downloads per subnet to one device at a time.  Set throttling to 25%.  That way only one machine per subnet can go to the source to download the software. 

           

          2.  Then set you bandwith usage options at whatever you feel is appropriate. 

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          • 2. Re: Questions on Targeted Multicasting
            MarXtar ITSMMVPGroup

            What Ty says haolds some weight mainly because the number of subnets you have is a bit of a barrier to targeted multicast. His suggested mechanism will have the same bandwidth control that you are trying to achieve but will rely more heavily on peer download once the package has made it to a machine within the subnet.

             

            The setting of 5 for the multicast rep is as you expected; only 5 multicast representatives can be active at any one time. With 1500+ subnets this will take a long time before it gets through all of the subnets.

             

            If the error is that it can't find a representative, then that means that at the time the multicast was attempted, the core server could not find a machine within that subnet that was online and able to be a subnet representative. If the job is taking so long, then most likely the attempt was at night when everything was off. HOWEVER, there have been a couple of mentions on the community where people have see LANDesk fail to find a multicast rep when machines are online so maybe worth checking.

             

            I would modify Ty's suggestion slightly depending on your environment. I would create a multicast job targeting the machines in the largest subnets so that as many machines as possible get the package (and probably increase the number of multicast reps). This could be a multicast only job with the policy being something done afterwards. Main thing is to get the package to as many machines as possible within a reasonable time so that peer download works very effectively.

             

            The smaller subnets will be fine with Ty's suggestion.

             

            Mark McGinn

            MarXtar Ltd

            http://www.marxtar.com

             

            The One-Stop Shop for LANDesk Enhancements

            - Wake-On-WAN - Distributed Wake-On-LAN, Scheduled Power Down, and SWDist Sequencing

            • 3. Re: Questions on Targeted Multicasting
              Rookie

              Thank you both for your input.  I went back and checked my settings, I do have "Limit remote downloads to one device per subnet" checked.  So, my bottleneck is that my "Maximum number of multicast domain representatives working simultaneously" is set to 5.  Should that be bumped up to match the setting for "Number of devices for simultaneous distribution" (currently set to 40)?

              • 4. Re: Questions on Targeted Multicasting
                MarXtar ITSMMVPGroup

                There's no hard and fast rule on that because it is down to what your core server and WAN links can handle. In theory if you set it to 40, it will still be less overhead than 1500 subnets with one download happening each. I've never had to put it that high before so the most scientific answer I can offer unfortunately is 'suck it and see'.

                 

                Mark McGinn

                MarXtar Ltd

                http://www.marxtar.com

                 

                The One-Stop Shop for LANDesk Enhancements

                - Wake-On-WAN - Distributed Wake-On-LAN, Scheduled Power Down, and SWDist Sequencing