IPv4_Multicast

packetlife.net by Jeremy Stretch v2.0 IPV4 MULTICAST Layer 2 Addressing 224.0.0.0/24 Group Ranges 224.0.1.0/24 232.0.0.0/8 233.0.0.0/8 Local network control Internetwork control Source-specific GLOP (RFC 3180) 239.0.0.0/8 Admin-scoped IGMP Configuration ip multicast-routing ! interface FastEthernet0/0 ip pim {sparse-mode | dense-mode | sparse-dense-mode} ip pim version {1 | 2} Distribution Trees Source-Rooted Provides the shortest paths from the source to receivers Shared A common set of links which carry all multicast traffic; statically configured IGMP Troubleshooting show ip igmp show ip igmp group 224.0.0.1 Common Groups 224.0.0.2 224.0.1.39 224.0.1.40 All hosts All routers Cisco RP Announce Cisco RP Discovery IGMP IGMPv2 Adds support for dynamic leave requests and querier election to original IGMP IGMPv3 Adds multicast source filtering to v2 IGMP Snooping A switch passively inspects IGMP requests to determine which hosts should receive multicast traffic show ip igmp interface show ip igmp snooping ip igmp join-group Terminology Internet Group Management Protocol (IGMP) Hosts send IGMP requests to local routers to join multicast groups Reverse Path Forwarding (RPF) Verifies that multicast traffic travels in the reverse direction of unicast traffic, away from the tree root Cisco Group Management Protocol (CGMP) A proprietary protocol used by switches to obtain multicast membership information for end hosts (deprecated) IGMP Support IGMP Snooping Router(config-if)# ip igmp [version <#>] Switch(config)# ip igmp snooping Protocol Independent Multicast (PIM) Dense Mode The initial tree encompasses all multicast routers; after a period of time, routers without IGMP members prune back branches Sparse-Dense Mode Allows a PIM-enabled interface to function in either sparse or dense mode per group Sparse Mode The tree is grown from a central rendezvous point out to the multicast source and recipients PIMv1 Provides automatic RP discovery with Auto-RP (Cisco proprietary) PIMv2 Automatic RP discovery is accomplished by the bootstrap router (BSR) method (standard) PIM Configuration RP Configuration Manual Auto-RP Mapping Agent ip pim rp-address ip pim send-rp-discovery scope Auto-RP Candidate BSR Candidate ip pim send-rp-announce ip pim bsr-candidate BSR RP Candidate ip pim rp-candidate PIM Troubleshooting show ip mroute show ip pim interface show ip pim neighbor show ip pim rp [mapping] show ip rpf IGMPv1 Original IGMP specification 239.142.57.6 01-00-5E-0E-39-06 11101111 10001110 00111001 00000110 00000001 00000000 01011110 00001110 00111001 00000110