We have set "solicit-router-advertisement-unicast" in the dynamic-profile and see it correctly configured / expanded with show dynamic-profile session client-id, but the outgoing unsolicit packets still use the multicast MAC address 0x333300.

MX BNG sends the IPv6 Unsolicit Router Advertisement with an multicast MAC for DHCP subscribers even if "solicit-router-advertisement-unicast" is configured in the dynamic profile

The "solicit-router-advertisement-unicast" shouldnt confiugured on the VLAN dynamic-profile, instead, we should have it in the subscriber dynamic-profile. Following below to get the desired output.

Key configuration: 

• Enable force-ra-unicast-dst globally. Noted, this is a hidden command in JUNOS.
• Enable solicit-router-advertisement-unicast in subscriber dynamic-profile, ie, the profile for PPPoE and DHCP session. 

system {

   services {

     subscriber-management {

       overrides {

         force-ra-unicast-dst;

       }

       enable;

     }

   }

}

/* Enable the [protocols router-advertisement] on subscriber(DHCP/PPPoE) dynamic-profile, don't configure router-advertisement on the VLAN profile.

dynamic-profiles {

  VLAN-DEMUX-PROF {

    routing-instances {

      "$junos-routing-instance" {

        interface "$junos-interface-name" {

          any;

        }

      }

    }

    interfaces {

      demux0 {

        unit "$junos-interface-unit" {

          actual-transit-statistics;

          no-traps;

          proxy-arp;

          vlan-tags outer "$junos-stacked-vlan-id" inner "$junos-vlan-id";

          demux-options {

            underlying-interface "$junos-interface-ifd-name";

          }

          family inet {

            unnumbered-address "$junos-loopback-interface";

          }

          family inet6 {

            unnumbered-address "$junos-loopback-interface";

          }

        }

      }

    }

  }

  DHCP-DEMUX-PROF {

    routing-instances {

      "$junos-routing-instance" {

        interface "$junos-interface-name" {

          any;

        }

        routing-options {

          access {

            route $junos-framed-route-ip-address-prefix {

              metric "$junos-framed-route-cost";

              preference "$junos-framed-route-distance";

            }

          }

        }

      }

    }

    interfaces {

      "$junos-interface-ifd-name" {

        unit "$junos-underlying-interface-unit" {

          family inet {

            mtu "$junos-interface-mtu";

          }

          family inet6 {

            mtu "$junos-interface-mtu";

          }

        }

      }

    }

    protocols {

      router-advertisement {

        interface "$junos-interface-name" {

          solicit-router-advertisement-unicast;

        }

      }

    }

  }

}