WB1 8.27 Source Specific Multicast

8.27 Source Specific Multicast

• Using the default multicast group range enable PIM SSM functionality on your network.
• R6 should join the multicast feed (150.1.10.10,232.6.6.6).
• Ensure that the “ip pim bsr-border” commands have been removed from R1 and R4 VLAN 146 interfaces.

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Classic multicast delivery technologies use IGMPv2 and PIM DM/SM and are
known as “Any Source Multicast” or ASM. That is, receivers agree to accept
traffic from any source. This is why Rendezvous Points are actually needed in
PIM SM - to allow receivers to discover new sources. The core of PIM SSM
protocol is the use of IGMPv3 signaling by clients. This client-side protocol allows
receivers to specify sources that they want to listen to explicitly. That is, the host
may explicitly ask to join group G at source S. PIM SSM works in association
with IGMPv3 in building shortest-path trees (SPT) only, towards the sources.
There are no shared trees in PIM SSM and no RPs are used. Thus, there is no
need to use auxiliary protocols like BSR or Auto-RP to distribute RP information.
Notice that source discovery is outside the scope of PIM SSM and IGMPv3, and
must be accomplished via some other means, like global directory services.

Configuring PIM SSM is relatively straight-forward, since it uses regular PIM
messages. You just need to specify the range of groups that are using SSM
signaling with the command ip pim ssm range {default|range <Standard-ACL>}.
The default keyword means that range 232.0.0.0/8 will
be used for SSM. For the groups in the SSM range, no shared trees are allowed
and the (*,G) joins are dropped.

The second step in configuring PIM SSM is enabling IGMPv3 on the interfaces
connected to the receivers capable of using this protocol. Without IGMPv3 there
can be no use of PIM SSM, as no other IGMP version allows sources to be
selected by the receivers explicitly in order to build shortest-path trees.

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R1, R3, R4, R5, SW2, SW4:
ip pim ssm default

R1:
interface FastEthernet 0/0
ip igmp version 3

R6:
interface FastEthernet 0/0.146
ip igmp version 3
ip igmp join 232.6.6.6 source 150.1.10.10

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PIM SSM is generally easier to configure than ASM, as it does not require the
complicated RP infrastructure. All you need to do is verify the SPT toward the
explicit source.

Rack1R1#show ip igmp groups 232.6.6.6 detail
Flags: L - Local, U - User, SG - Static Group, VG - Virtual Group,
       SS - Static Source, VS - Virtual Source,
       Ac - Group accounted towards access control limit
Interface:      FastEthernet0/0
Group:          232.6.6.6
Flags:          SSM
Uptime:         00:00:44
Group mode:     INCLUDE
Last reporter:  155.1.146.6
Group source list: (C - Cisco Src Report, U - URD, R - Remote, S - Static,
                    V - Virtual, M - SSM Mapping, L - Local,
                    Ac - Channel accounted towards access control limit)
  Source Address   Uptime    v3 Exp   CSR Exp   Fwd  Flags
  150.1.10.10      00:00:44  00:02:54  stopped   Yes  R
Rack1R1#
Rack1R1#
Rack1R1#show ip mroute 232.6.6.6 150.1.10.10
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
       L - Local, P - Pruned, R - RP-bit set, F - Register flag,
       T - SPT-bit set, J - Join SPT, M - MSDP created entry,
       X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
       U - URD, I - Received Source Specific Host Report,
       Z - Multicast Tunnel, z - MDT-data group sender,
       Y - Joined MDT-data group, y - Sending to MDT-data group
Outgoing interface flags: H - Hardware switched, A - Assert winner
 Timers: Uptime/Expires
 Interface state: Interface, Next-Hop or VCD, State/Mode
(150.1.10.10, 232.6.6.6), 00:01:24/00:02:33, flags: sTI
  Incoming interface: Serial0/0.1, RPF nbr 155.1.0.5
  Outgoing interface list:
    FastEthernet0/0, Forward/Sparse, 00:01:24/00:02:33
Rack1R1#

Rack1R5#show ip mroute 232.6.6.6 150.1.10.10
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
       L - Local, P - Pruned, R - RP-bit set, F - Register flag,
       T - SPT-bit set, J - Join SPT, M - MSDP created entry,
       X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
       U - URD, I - Received Source Specific Host Report,
       Z - Multicast Tunnel, z - MDT-data group sender,
       Y - Joined MDT-data group, y - Sending to MDT-data group
Outgoing interface flags: H - Hardware switched, A - Assert winner
 Timers: Uptime/Expires
 Interface state: Interface, Next-Hop or VCD, State/Mode
(150.1.10.10, 232.6.6.6), 00:02:05/00:03:22, flags: sT
  Incoming interface: FastEthernet0/0, RPF nbr 155.1.58.8
  Outgoing interface list:
    Serial0/0, 155.1.0.1, Forward/Sparse, 00:02:05/00:03:22
Rack1R5#

Rack1SW2#show ip mroute 232.6.6.6 150.1.10.10
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
       L - Local, P - Pruned, R - RP-bit set, F - Register flag,
       T - SPT-bit set, J - Join SPT, M - MSDP created entry,
       X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
       U - URD, I - Received Source Specific Host Report,
       Z - Multicast Tunnel, z - MDT-data group sender,
       Y - Joined MDT-data group, y - Sending to MDT-data group
       V - RD & Vector, v - Vector
Outgoing interface flags: H - Hardware switched, A - Assert winner
 Timers: Uptime/Expires
 Interface state: Interface, Next-Hop or VCD, State/Mode
(150.1.10.10, 232.6.6.6), 00:02:45/00:02:41, flags: sT
  Incoming interface: Port-channel1, RPF nbr 155.1.108.10
  Outgoing interface list:
    Vlan58, Forward/Sparse, 00:02:45/00:02:41
Rack1SW2#

Rack1SW4#show ip mroute 232.6.6.6 150.1.10.10
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
       L - Local, P - Pruned, R - RP-bit set, F - Register flag,
       T - SPT-bit set, J - Join SPT, M - MSDP created entry,
       X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
       U - URD, I - Received Source Specific Host Report,
       Z - Multicast Tunnel, z - MDT-data group sender,
       Y - Joined MDT-data group, y - Sending to MDT-data group
       V - RD & Vector, v - Vector
Outgoing interface flags: H - Hardware switched, A - Assert winner
 Timers: Uptime/Expires
 Interface state: Interface, Next-Hop or VCD, State/Mode
(150.1.10.10, 232.6.6.6), 00:03:25/00:03:03, flags: sT
  Incoming interface: Loopback0, RPF nbr 0.0.0.0
  Outgoing interface list:
    Port-channel1, Forward/Sparse, 00:03:25/00:03:03
Rack1SW4#       

Rack1SW4#ping 232.6.6.6 repeat 3
Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 232.6.6.6, timeout is 2 seconds:
Nov 29 17:31:46.007 TPE: IP(0): s=155.1.10.10 (Vlan10) d=232.6.6.6 id=181, ttl=254, prot=1, len=114(100), mroute olist null
Nov 29 17:31:46.007 TPE: IP(0): s=150.1.10.10 (Loopback0) d=232.6.6.6 (Port-channel1) id=181, ttl=254, prot=1, len=100(100), mforward
Reply to request 0 from 155.1.146.6, 59 ms
Reply to request 0 from 155.1.146.6, 59 ms
Reply to request 0 from 155.1.146.6, 59 ms
Rack1SW4#