Additional multicast stuff (not on blueprint)

1.6.x Static multicast routes (mroute)

General information on “Static multicast routes (mroute)":

• PIM relies on RPF which means that the incoming interface of a multicast packet needs also to be the shortest path to the source address of the incoming multicast packet
• Sometimes things like redistribution, PIM and/or IGP not enabled on a interface, […] can lead to an RPF failure
• Traffic Engineering also requires manual modification of multicast routes
• All of this can be fixed with static multicast routes (mroute)
• Important: Compared to “normal” static routes which defines the destination prefix and next-hop/outgoing if, static multicast routes define the source prefix and the next-hop/incoming interface!

“Static multicast routes (mroute)” CLI configuration commands:

## Configuring a static IPv4 multicast route
Router(config)# ip mroute <network> <mask> [<next-hop-ip> | <ingress-if>] [<ad>]

## Configuring a static IPv6 multicast route
Router(config)# ipv6 route <network> [<next-hop-ip> | <exit-if>] [<ad>] multicast

“Static multicast routes (mroute)” CLI show commands:

## Showing the IPv4 multicast routing table
Router# show ip mroute

## Showing the IPv6 multicast routing table
Router# show ipv6 mroute

1.6.x Multicast routing over a unicast network

General information on “Multicast routing over a unicast network”:

• There are multiple ways routing multicast traffic over a unicast (transit) network:
  1. Using GRE tunnels between the two multicast domains
     • Requires the configuration of a GRE tunnel between the two multicast domains
     • PIM-SM needs to be enabled on the tunnel interfaces
     • Either static unicast/multicast routes or a dynamic routing protocol can be used
     • RPs (if each site has its own) need to be “connected” using MSDP
  2. Using MP-BGP to announce multicast routes
     • Requires the configuration of MP-BGP (multicast AF) over the transit network
     • PIM-SM needs to be enabled on the BGP enabled interfaces
     • RPs (each site NEEDS its own!) need to be “connected” using MSDP

1.6.x Embedded RP

General information on “Embedded RP”:

• Embedded RPs is a PIMv6 feature which allows the sending/receiving host to signal which RP the multicast router should use
• This allows for a much more simplified multicast configuration since the RP address only needs to be defined on the to-be-used RP itself
• Embedded RP address construction:
  • FF7S:0IHH:PPPP:PPPP:PPPP:PPPP:GGGG:GGGG
  • S = Scope
  • I = Interface Identifier (The last 4 bits of the RP address)
  • H = Prefix Length bits in hex
  • P = Prefix
  • G = Multicast Group
• Embedded RP address example:
  • RP address: 2001:0DB8:1234:ABCD::3/64
  • Multicast Group: FF08::1
  • Embedded RP Address: FF78:0340:2001:0DB8:1234:ABCD:FF08:1