Page Links: Ranges, IGMP, PIM, MOSPF, MBGP, MSDP, Useful

IPv4 Address Ranges

  • 224/4 = →
  • 224/8 = link local only
  • 232/8 = SSM
  • 233/8 = GLOP


  • Host to default gateway router.
  • IGMP Snooping on LAN switch: reduces LAN traffic.
  • IGMP v3: adds explicit leave.


  • Router to router.
  • PIM-SM:
    • explicitly builds unidirectional shared tree (rooted at the RP).
  • PIM-DM:
    • implicitly builds shortest path trees by flooding multicast traffic domain-wide and then pruning back where not needed (i.e. no receivers).
  • PIM-SSM:
    • build tree rooted at one source.


  • Extension to OSPF that allows routers to share info about group memberships.


  • Extension to BGP.
  • Allows multicast topology info to be exchanged separately from normal unicast info.
  • Still relies on underlying PIM.


  • Allows PIM-SM to have RP redundancy.
  • Allows inter-domain multicast.
  • Each multicast tree has an RP, and all RPs are peers.

Useful Articles

  • IGMP.  [ipCisco]
  • Unicast, Broadcast, Multicast, Anycast.  [ipCisco]
    • Multicast MAC addresses.  [ipCisco]
    • Multicast IP addressing.  [ipCisco]
  • Multicast in an EVPN world.  [NANOG 72 YouTube]
  • Create IP multicast tree graphs from operational data.  [ipSpace]
  • DMVPN or firewall-based VPNs?  [ipSpace]
  • Using FQDN for DMVPN hubs.  [Fragmentation Needed]
  • Where do you want to move the complexity?  [ipSpace]
  • Regional internet exits in large DMVPN deployment.  [ipSpace]
  • Inter-VRF NAT in DMVPN deployments.  [ipSpace, ipSpace]
  • Label switched multicast - Ethernet header.  [Packet Mischief]
  • The future of multicast and QoS.  [ipSpace]
  • Label Switched Multicast (LSM) -- an introduction.  [Packet Mischief]
  • OSPF vs EIGRP for DMVPN.  [Packet Mischief]
  • DMVPN split default routing.  [ipSpace]
    • DMVPN split default routing and internet access.  [ipSpace]
  • PMTUD doesn't work with IP multicast.  [ipSpace]
  • More PIM-BiDir considerations.  [Lost In Transit]
  • IPv6 multicast.  [Lost In Transit]
  • Next-generation multicast: NG-MVPN.  [Lost in Transit]
  • HSRP-aware PIM.  [Lost In Transit]
  • Scaling overlay virtual networking videos.  [ipSpace]
  • Unreliable multicast means unreliable VMware VSAN.  [EtherealMind]
  • Using EEM to speed up multicast convergence when receiver is dually connected.  [Lost in Transit]
  • Lessons learned from deploying multicast.  [Lost in Transit]
  • How to configure IP multicast PIM on ECMP (on Mellanox).  [EtherealMind]  [Mellanox]
  • Interdomain multicast.  [Reddit]
  • Scaling BGP-based DMVPN networks.  [ipSpace]
  • The fundamental difference between phase 2 and phase 3 DMVPN.  [ipSpace]
  • Easy to follow resource for multicast.  [Reddit]
  • IGMP and PIM in multicast VXLAN transport networks.  [ipSpace]
  • BGP routing in DMVPN networks.  [ipSpace]
  • IGMP snooping in IPTV.  [StackExchange]
  • Combining DMVPN with existing MPLS/VPN network.  [ipSpace]
    • Integrating DMVPN-based Internet VPN with MPLS/VPN WAN.  [ipSpace]
  • RSVP over DMVPN.  [ipSpace]
  • More private AS numbers.  [ipSpace]
  • The impact of changed NHRP behaviour in DMVPN networks.  [ipSpace]
  • VM-level IP multicast over VXLAN.  [ipSpace]
  • NHRP rate limiting can hurt your DMVPN network.  [ipSpace]
  • Migrating from a phase 1 DMVPN to a phase 2/3 network.  [ipSpace]
  • Redundant DMVPN designs.  [ipSpace: part 1, part 2]
  • Multiple DMVPNs on a single hub.  [PacketLife]
  • NVGRE -- because one standard just wouldn't be enough.  [IOS Hints]
  • OSPF-over-DMVPN using two hub routers.  [IOS Hints]
  • DMVPN as a backup for MPLS/VPN.  [IOS Hints]
  • Video: Auto-RP over NBMA design issues.  [CCIE Blog]
  • More OSPF-over-DMVPN questions.  [IOS Hints]
  • Understanding static multicast routes.  [CCIE Blog]
  • QoS in large-scale DMVPN networks.  [IOS Hints]
  • Spoke-to-spoke IP multicast over DMVPN?  [IOS Hints]
  • Understanding advanced PIM shared tree designs.  [CCIE Blog]
  • Troubleshooting multicast routing.  [CCIE Blog]
  • PIM-SSM.  [PacketLife]
  • IP multicast is like Banyan Vines.  [IOS Hints]
  • RFC 5790 - lightweight IGMPv3 and MLDv2 protocols - another shot at multicast - but why?  [Etherealmind]
  • RFC 5771: IANA guidelines for for IPv4 multicast address assignments.  [IETF]