8 IPv6 Multicast OS support All IPv6 systems (should) support MLDv1Linux and Windows Vista support MLDv2
9 ASM: PIM-SM, RP and embedded RP Multicast routing is usually done via PIM-SMPIM-SM requires an RP for source discoveryAll routers must use the same RP and somehow know its addressInitially packet from a source will be sent to the RPWhen a host joins a group, join messages are sent hop by hop towards the RPThe RP serves as a meeting place between source and receiversThis works well within a site or a single administrative domainMSDP doesn’t scale since source information is flooded to all RPs, so IETF decided not to have MSDP for IPv6Embedded RP encodes the RP address into the group addressThe difference is that with MSDP, there is only (S, G) joints between domains, while with embedded RP, there will also be (*, G) joints between domains
10 SSM: PIM-SM SSM is available for both IPv4 and IPv6 Some believe only SSM is needed for interdomain multicastSSM simplifies multicast signaling in the networkno needed for RPs, PIM register, switching between shared and source specific trees …But very difficult for multi-party applicationsconferencing where everyone is a source and everyone needs to know the IP address of othersSSM is supported by very few applications and systemsEdge routers and hosts need to support MLDv2Hosts need to support RFC3678, which is the API for specifying source filtersApplications need to be changed to support this API
11 For cross TEIN2 multicast communication G=FFxE::
12 For TEIN2 Backbone S=2001:254::/32 G=ff3e:0020:2001:254:x:x:x:xHowever, the static RP is not supported by TEIN2 backbone, the embedded RP should be used for the NRENs
13 For TEIN2 Backbone S=2001:254::/32 Embedded RP (BJ) A=2001:254::1 G=ff7e:0120:2001:254:x:x:x:xEmbedded RP (HK) A=2001:254::2 G=ff7e:0220:2001:254:x:x:x:xEmbedded RP (SG) A=2001:254:8000::1 G=ff7e:0130:2001:254:8000:x:x:x
14 For TEIN2 Backbone S=2001:254::/32 G=ff3e::x:x:x:xSSM is more reliable.
36 Discussion (1) Router related issues For the Juniper router (any model and any software version), you cannot configure ASM (IGMPv2/MLDv1) and SSM (IGMPv3/MLDv2) in the same interface. Therefore, you should configure the interface of the router to the corresponding IGMP/MLD version for the the specific testing (ASM or SSM). Also note that this is for the access router directly connected to the host which is receiving the multicast packets and it does not effect the multicast packet sending process.For the Cisco router (for example 7600 and IOS 12.2(18)SXD6), you cannot configure the IPv4 multicast and IPv6 multicast in the same interface. To fix the problem, you can use IOS 12.2(18)SXF8.For the Cisco router (for example 7600 and IOS 12.2(18)SXF8), it does not support BGP address family IPv6 multicast (SAFI=2 and SAFI=3). You should use the cisoc IOS hidden command to tell router to use the unicast routing table for the multicast RPF check. Example: 7600(config)#ipv6 rpf use-bgp
37 Discussion (2) Host related issues The Microsoft Window XP cannot support IPv6 SSM. Therefore, IPv6 ssmping test will fail in the Windows system. In addition XP cannot support IPv6 DNS query, therefore it may not be able to resolve the DNS IPv6 address mapping in pure IPv6 environmentWe recommend version or higher for the Linux system to test the IPv6 SSM and ASM embedded RP. The old versions (for example ELsmp) cannot work correctly.Be careful on the value of IP_MULTICAST_TTL or IPV6_MULTICAST_HOPS of the multicast senders. The old version of the Linux system (for example ) set this value to 1 and the multicast pakcet can only be received in the same subnet and cannot be sent cross routers.Microsoft Internet Explorer does not support URL containing IPv6 address (for example the URL . You may use Firefox.
38 Discussion (3)For the inter-domain multicast, SSM is much more reliable and controllableWindows XP is the most popular DVTS platform, but it does not support SSMUsers may use Linux platform to reply the SSM and ASM, use dvmcast tool or similar tools
40 Suggestions Form an active inter-domain IPv6 multicast WG Publish an group address usage guidelineRun distributed IPv6 multicast measurement serversPromote IPv6 multicast applications
41 Remarks Multicast is very useful for academic applications IPv6 multicast has more flexibilityTools and router access are both important.IPv6 multicast configuration and debugging process is an enjoyable process (-: