Multicast sessions disappearing

  • I have a Fog 1.5.4 install on CentOS 7. When I create a mulitcast session, I see the session at the bottom of the page, but target machines can’t find the session and when I refresh the page the session is gone. I have tested by making a session and then immediately refreshing the page once I see the session at the bottom, and the session is gone. Any ideas?

  • Senior Developer

    @vanlue-it-guy Leave that at 0 for disabled. It’s for those people who are using the and want to use a different multicast address, (say for example

  • Tom thanks for the help. I’ve done your settings and will be testing multicast again soon. Do I need to fill in an address for Multicast Address as well or just leave that blank?

  • Senior Developer

    @vanlue-it-guy You likely need to clear out the old sessions. This is relatively simple.

    Open your mysql instance. Typically done with: mysql -u root fog

    Enter the commands:

    truncate table multicastSessionsAssoc;
    truncate table multicastSessions;

    Then exit to return to the terminal.

    Once that’s done, restart your MulticastManager service with: systemctl restart FOGMulticastManager

    Now, before you create a new session, goto FOG Configuration Page->FOG Settings->Expand All, search the page for Rendezvous. In the text field enter your FOG Servers IP Address, then click the save button that the rendezvous item is contained within.

    Then create your session.

    Names cannot be reused if their in use currently. (It should blank the name once the task is cancelled or completed, if it’s not doing that let me know and I can take a look at that.)

    Basically, if you’re on a flat network with a central switch, multicast defaults to go through, but if you have multiple switches that need traversing, often times they don’t allow multicast to go across that ip, especially true for vlans. Of course this is assuming your network is configured to allow multicast to begin with.

  • Tom, I ran the commands you provided and I’m now on Now I have multicast sessions that some stay, and some disappear. Also, it seems as though I can’t reuse the same name for a session. Lastly, when I am able to create a session and get clients to join, it gets to the blue partclone screen and seems to hang. It never starts deploying the image. I’m happy to provide any info I can.


  • Senior Developer

    This has been dicussed many times already. It’s a known issue, and I believe this to be fixed in the working branch.

    git clone
    cd fogproject
    git checkout working
    cd bin
    ./ -y

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