IP Multicast Survival Guide Part 2

Transcription

1 IP Multicast Survival Guide Part 2 Second Edition Beau Williamson CCIE 1356 R/S Emeritus CiscoLive Distinguished Speaker aka Multicast Survivorman

2 Rules of Engagement Silence... I kill you! I mean your Cell Phones and Laptops that is. Violators must buy Beer for everyone in the room! Ask questions at any time. 10,000 Bonus Points awarded for Good Questions 20,000 Bonus Points awarded for Great Questions 30,000 Bonus Point deduction for intentionally stumping presenter Remember: I haven t touched this stuff in years so I m a bit rusty. 2

3 Survival Guide Goal To provide a deep dive into PIM ASM Protocol mechanics in order to provide you with a master IP Multicast survival toolkit that will help you to go alone and unafraid into the CCIE Lab Wilderness of IP Multicast1. 1 You still may be asked to perform unnatural network acts in your CCIE lab. 3

4 Agenda PIM ASM Review PIM Neighbor Discovery PIM State & State Rules PIM SSM Joining PIM SSM Pruning PIM ASM Joining PIM ASM Registering PIM ASM SPT Switchover PIM ASM Pruning PIM Bidir Joining PIM Bidir Senders Geekometer 4

5 PIM ASM Review 5

6 PIM-SM Shared Tree Join RP (*, G) Join Shared Tree (*, G) State Created Only Along the Shared Tree Receiver 6

7 PIM-SM Sender Registration Source RP Traffic Flow Shared Tree Source Tree (S, G) Register (S, G) Join (unicast) Receiver (S, G) State Created Only Along the Source Tree 7

8 PIM-SM Sender Registration Source RP Traffic Flow Shared Tree Source Tree (S, G) Register (S, G) Register-Stop (unicast) (unicast) Receiver (S, G) Traffic Begins Arriving at the RP via the Source Tree RP Sends a Register-Stop Back to the First-Hop Router to Stop the Register Process 8

9 PIM-SM Sender Registration Source RP Traffic Flow Shared Tree Source Tree Receiver Source Traffic Flows Natively Along SPT to RP From RP, Traffic Flows Down the Shared Tree to Receivers 9

10 PIM-SM SPT Switchover Source RP Traffic Flow Shared Tree Source Tree (S, G) Join Receiver Last-Hop Router Joins the Source Tree Additional (S, G) State Is Created Along New Part of the Source Tree 10

11 PIM-SM SPT Switchover Source RP Traffic Flow Shared Tree Source Tree (S, G)RP-bit Prune Receiver Traffic Begins Flowing Down the New Branch of the Source Tree Additional (S, G) State Is Created Along the Shared Tree to Prune Off (S, G) Traffic 11

12 PIM-SM SPT Switchover Source RP Traffic Flow Shared Tree Source Tree Receiver (S, G) Traffic Flow Is Now Pruned Off of the Shared Tree and Is Flowing to the Receiver via the Source Tree 12

13 PIM-SM SPT Switchover Source RP Traffic Flow Shared Tree Source Tree (S, G) Prune Receiver (S, G) Traffic Flow Is No Longer Needed by the RP so It Prunes the Flow of (S, G) Traffic 13

14 PIM-SM SPT Switchover Source RP Traffic Flow Shared Tree Source Tree Receiver (S, G) Traffic Flow Is Now Only Flowing to the Receiver via a Single Branch of the Source Tree 14

15 PIM Packets 15

16 PIM Packet Header PIMv2 is assigned protocol number 103 Ver Type Reserved Checksum Ver: PIM Version = 2 Type: 0 = Hello 1 = Register (SM only) 2 = Register-Stop (SM only) 3 = Join/Prune 4 = Bootstrap (SM BSR only) 5 = Assert 6 = Graft (DM only) 7 = Graft-Ack (DM only) 8 = C-RP-Announcement (SM BSR only) 31 For Your Reference PIMv2 messages are multicast to the ALL-PIM-Routers ( ) group with a TTL of 1. 16

17 PIM Hello Messages For Your Reference Ver Type Reserved Checksum Option Type Option Length Option Value Option Type Option Value Option Length Option Types: 1 = Holdtime (Period of time in seconds before this PIM neighbor times out.) 19 = DR Priority 20 = Generation ID 17

18 PIM Join/Prune Packets Ver Type Reserved Checksum Upstream Neighbor Address (Encoded-Unicast) Reserved Num. Groups Holdtime Group List 31 Upstream Neighbor Address: IP address of RPF of upstream neighbor Holdtime: Period of time in seconds before this join/prune times out. Num. Grps # of Groups in Group list For Your Reference Group List: List (by group) of sources to Join and/or Prune. 18

19 PIM Group Lists 15 Group-1 (Encoded-Group) Num. Join Sources Num. Prune Sources Join Source-1 (Encoded-Source) Join Source-n (Encoded-Source) Prune Source-1 (Encoded-Source) 31 Group-x Group IP address Num. Join Sources # of Joins for Group-x Num. Prune Sources # of Prunes for Group-x For Your Reference Prune Source-n (Encoded-Source) Num. Join Sources Group-2 (Encoded-Group) Num. Prune Sources Join/Prune Source-y Encoded Source address to be Joined/Pruned. Group Lists are used in Join/Prune and Graft/Graft-Ack messages. 19

20 PIM Assert Packets R Ver Type Reserved Checksum Group Address (Encoded-Group) Source Address (Encoded-Source) Metric Preference Metric Group Address: Identifies Group of the Assert Source Address: Identifies Source of the Assert R: (Sparse Mode Only) 1 = Assert down RP Tree; 0 = Assert Down SPT Metric Preference: Admin. Distance of unicast routing protocol Metric: Unicast routing protocol metric 31 For Your Reference 20

21 PIM Register Packets 3 Sparse Mode Only 7 15 Ver Type Reserved Checksum B N Reserved 31 For Your Reference Multicast Data Packet B = Border Bit: Indicates DR is a border router performing a proxy-register N = Null Register Bit: Indicates DR is sending a Null-Register before expiring its register-suppression timer. Multicast Data Packet: The original packet sent by the source. For periodic sending of registers, this part is null. 21

22 PIM Register-Stop Packets For Your Reference Ver 3 Sparse Mode Only 7 15 Type Reserved Checksum Group Address (Encoded-Group) Source Address (Encoded-Source) 31 Group Address: The Group address from the Register message. Source Address: IP host address of Source from multicast data packet in Register message. 22

23 Encoded Unicast Addresses For Your Reference 7 15 Addr Family Encoding Unicast Address Unicast Address 31 Addr Family: IANA Address Family Identifier (e.g. 1=IPv4) Encoding: Type of encoding within Address Family Unicast Address: Unicast Address of the target device. 23

24 Encoded Source Addresses For Your Reference Addr Family Encoding Rsvd SWR Source Address... Mask Len 31 Addr Family: IANA Address Family Identifier (e.g. 1=IPv4) Encoding: Type of encoding within Address Family S = Sparse Mode bit Indicates Sparse Mode Group. W = Wildcard bit Indicates Join/Prune is a (*,G) Join/Prune. R = RP bit Indicates this Join/Prune should be sent up Shared Tree toward RP. Mask Len Number of bits in the prefix of the Group Address. Source Address Address of Multicast Source 24

25 Encoded Group Addresses For Your Reference 3 Addr Family 7 15 Encoding Reserved Group Address... Addr Family: IANA Address Family Identifier (e.g. 1=IPv4) Encoding: Type of encoding within Address Family Mask Len Number of bits in the prefix of the Group Address. Group Address Multicast Group Address Mask Len 31 25

26 PIM Neighbor Discovery 26

27 PIM Neighbor Discovery PIM Router 2 Highest IP Address Elected as DR (Designated Router) PIM Hello PIM Hello PIM Router PIMv2 Hellos are periodically multicast to the All-PIM-Routers ( ) group address (default = 30 seconds) If the DR times-out, a new DR is elected The DR is responsible for sending all Joins and Register messages for any receivers or senders on the network 27

28 PIM Neighbor Discovery - IOS wan-gw8>show ip pim neighbor PIM Neighbor Table Neighbor Interface Uptime/Expires Ver Mode Address Prio/Mode FastEthernet0/0 2w1d/00:01:24 v2 1 / B S FastEthernet0/0 2w6d/00:01:01 v2 1 / B S FastEthernet0/0 7w0d/00:01:14 v2 5 / DR B S FastEthernet0/0 7w0d/00:01:13 v2 1 / B S FastEthernet0/0 7w0d/00:01:02 v2 1 / B S Serial :47:11/00:01:16 v2 1 / B S Serial :47:22/00:01:08 v2 1 / B S Serial :47:07/00:01:21 v2 N / Serial0.70 1d4h/00:01:06 v2 N / Serial1.51 1w4d/00:01:25 v2 1 / B S Serial3.56 1d4h/00:01:20 v2 1 / B S Serial :53:25/00:01:03 v2 1 / B S 28

29 DR Failover A.2 (DR) /24.1 B Rtr-B>show ip pim neighbor PIM Neighbor Table Neighbor Address Interface Uptime Expires Mode Ethernet0 4d22h 00:01:18 Sparse-Dense (DR) Depends on neighbor expiration time Expiration time sent in PIM query messages Expiration time = 3 x <query-interval> Default <query-interval> = 30 seconds DR failover ~ 90 seconds (worst case) by default 29

30 PIM State & State Rules 30

31 PIM State Describes the state of the multicast distribution trees As understood by the router at that point in the network Represented by multicast routing (mroute) table entries Used to make multicast traffic forwarding decisions Composed of (*, G) and (S, G) entries Each entry contains RPF information Incoming (i.e. RPF) interface RPF Neighbor (upstream) Each entry contains an Outgoing Interface List (OIL) OIL may be NULL 31

32 PIM-SM State Example - IOS sj-mbone> show ip mroute 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 Outgoing interface flags: H - Hardware switched Timers: Uptime/Expires Interface state: Interface, Next-Hop or VCD, State/Mode (*, ), 2w1d/00:00:00, RP , flags: SJC Incoming interface: Serial0/1, RPF nbr Ethernet0/1, Forward/Sparse-Dense, 2w1d/00:01:40 Serial0/0, Forward/Sparse-Dense, 00:4:52/00:02:08 ( , ), 00:04:52/00:02:59, flags: CJT Incoming interface: Serial0/1, RPF nbr Ethernet0/1, Forward/Sparse-Dense, 00:00:10/00:02:49 Serial0/0, Forward/Sparse-Dense, 00:4:52/00:02:08 32

33 PIM-SM (*,G) State Rules in IOS (*,G) creation Receipt of a (*,G) Join or IGMP Report Automatically if (S,G) must be created Not applicable to SSM (*,G) reflects default group forwarding IIF = RPF interface toward RP OIL = interfaces That received a (*,G) Join or With directly connected members or Manually configured (*,G) deletion When OIL = NULL and No child (S,G) state exists 33

34 PIM-SM (S,G) State Rules in IOS (S,G) creation By receipt of (S,G) Join or Prune or By Register process Parent (*,G) created (if doesn t exist) Not applicable to SSM (S,G) reflects forwarding of S to G IIF = RPF Interface normally toward source RPF toward RP if RP-bit set Not applicable to SSM OIL = Initially, copy of (*,G) OIL minus IIF Not applicable to SSM (S,G) deletion By normal (S,G) entry timeout 34

35 PIM-SM OIL Rules in IOS Interfaces in OIL added By receipt of Join message Interfaces added to (*,G) are added to all (S,G) s Not applicable to SSM Interfaces in OIL removed By receipt of Prune message Interfaces removed from (*,G) are removed from all (S,G) s Not applicable to SSM Interface expire timer counts down to zero Timer reset (to 3 min.) by receipt of periodic Join or By IGMP membership report 35

36 PIM-SM Triggered Join/Prune Rules Triggering Join/Prune Messages (*,G) Joins are triggered when: The (*,G) OIL transitions from Null to non-null (*,G) Prunes are triggered when: The (*,G) OIL transitions from non-null to Null (S,G) Joins are triggered when: The (S,G) OIL transitions from Null to non-null The (S,G) RP bit is reset (S,G) Prunes are triggered when: The (S,G) OIL transitions from non-null to Null (S,G) RP-bit Prunes are triggered when: The (S,G) RPF info!= the (*,G) RPF info Not applicable to SSM 36

37 PIM-SM IOS State Flags S C I L P T = Sparse = Router has Directly Connected Host = Router Received Source Specific Host Report (SSM) = Local (Router is member) = Pruned (All interfaces in OIL = Prune) = Indicates at least one packet was forwarded via (S,G) entry Not applicable to SSM. T bit always set. 37

38 PIM-SM IOS State Flags J = Join SPT Not applicable to SSM In (*, G) entry Indicates SPT-Threshold is being exceeded Next (S,G) received will trigger join of SPT In (S, G) entry Indicates SPT joined due to SPT-Threshold If rate < SPT-Threshold, switch back to Shared Tree F = Register/First-Hop Not applicable to SSM In (S,G) entry S is a directly connected source Triggers the Register Process In (*, G) entry Set when F set in at least one child (S,G) 38

39 PIM-SM IOS State Flags R = RP bit Not applicable to SSM (S, G) entries only Set by (S,G)RP-bit Prune Indicates info is applicable to Shared Tree Used to prune (S,G) traffic from Shared Tree Initiated by Last-hop router after switch to SPT Modifies (S,G) forwarding behavior IIF = RPF toward RP (I.e. up the Shared Tree) OIL = Pruned accordingly 39

40 PIM Source-Specific Multicast (SSM) 40

41 Source Specific Multicast (SSM) Uses Source Trees only Assumes one-to-many model Most Internet multicast fits this model IP/TV also fits this model Hosts responsible for source discovery Typically via some out-of-band mechanism Web page, Content Server, etc. Eliminates need for RP RP discovery (BSR, AutoRP, Static) RP redundancy (BSR, AutoRP, MSDP, PIM-Anycast) RP placement and nurturing Eliminates need for shared trees SPT/RPT switchover complexity Eliminates need for interdomain PIM-SM complexity (MSDP) 41

42 SSM Overview Hosts join a specific source within a group Content identified by specific (S,G) instead of (*,G) Hosts responsible for learning (S,G) information Last-hop router sends (S,G) join toward source Shared Tree is never Joined or used Eliminates possibility of content Jammers Only specified (S,G) flow is delivered to host Eliminates Networked-Based Source Discovery No RPs for SSM groups Simplifies address allocation Dissimilar content sources can use same group without fear of interfering with each other 42

43 PIM SSM Joining 43

44 PIM SSM Joining - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 Rcvr2 ( , ), 00:00:09/00:02:51, flags: spt Incoming interface: Ethernet0/2, RPF nbr Null 44

45 PIM SSM Joining - IOS /2 Source Data Src / A / Source Tree 1 IGMPv3 Join Rcvr /0 /1 B /0 C /1 Rcvr2 1 Rcvr1 wishes to receive SSM S,G traffic. Sends IGMPv3 Join for S,G. 45

46 PIM SSM Joining - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 Rcvr2 ( , ), 00:00:14/00:02:45, flags: sti Incoming interface: Ethernet0/0, RPF nbr Ethernet0/1, Forward/Sparse, 00:00:14/00:02:45 B Creates ( , ) State 46

47 PIM SSM Joining - IOS /2 Source Data Source Tree Src Rcvr1 / (S,G) Join /0 /1 B A / /0 C /1 Rcvr2 2 B sends (S,G) Join towards Source. 47

48 PIM SSM Joining - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 Rcvr2 ( , ), 00:00:15/00:02:49, flags: st Incoming interface: Ethernet0/2, RPF nbr Null Ethernet0/0, Forward/Sparse, 00:28:03/00:02:43 A Updates ( , ) State 48

49 PIM SSM Joining - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 Rcvr2 49

50 PIM SSM Joining - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 IGMPv3 Join 3 Rcvr2 3 Rcvr2 wishes to receive SSM S,G traffic. Sends IGMPv3 Join for S,G. 50

51 PIM SSM Joining - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 Rcvr2 ( , ), 00:00:02/00:02:49, flags: sti Incoming interface: Ethernet0/0, RPF nbr Ethernet0/1, Forward/Sparse, 00:00:02/00:02:49 C Creates ( , ) State 51

52 PIM SSM Joining - IOS /2 Source Data Source Tree Src Rcvr1 / /0 /1 B A / (S,G) Join /0 C /1 Rcvr2 4 C sends (S,G) Join towards Source. 52

53 PIM SSM Joining - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 Rcvr2 ( , ), 00:00:15/00:02:49, flags: st Incoming interface: Ethernet0/2, RPF nbr Ethernet0/0, Forward/Sparse, 00:28:03/00:02:43 Ethernet0/1, Forward/Sparse, 00:00:03/00:02:48 A Updates ( , ) State 53

54 PIM SSM Joining - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 Rcvr2 54

55 PIM SSM Pruning 55

56 PIM SSM Pruning - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 Rcvr2 ( , ), 00:43:15/00:02:49, flags: st Incoming interface: Ethernet0/2, RPF nbr Ethernet0/0, Forward/Sparse, 00:43:15/00:02:44 Ethernet0/1, Forward/Sparse, 00:40:03/00:02:55 State in A Before Pruning 56

57 PIM SSM Pruning - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 Rcvr2 ( , ), 00:43:15/00:02:49, flags: sti Incoming interface: Ethernet0/0, RPF nbr Ethernet0/1, Forward/Sparse, 00:43:15/00:02:44 State in B Before Pruning 57

58 PIM SSM Pruning - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 Rcvr2 ( , ), 00:40:16/00:02:49, flags: sti Incoming interface: Ethernet0/0, RPF nbr Ethernet0/1, Forward/Sparse, 00:40:16/00:02:42 State in C Before Pruning 58

59 PIM SSM Pruning - IOS /2 Source Data Src / A / Source Tree Rcvr1 1 IGMP Leave /0 /1 B /0 C /1 Rcvr2 1 B is a Leaf router. Last Rcvr, leaves (S,G). 59

60 PIM SSM Pruning - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 Rcvr2 ( , ), 00:43:25/00:02:49, flags: sti stp Incoming interface: Ethernet0/0, RPF nbr Ethernet0/1, Forward/Sparse, 00:00:14/00:02:45 2 B removes /1 from (S,G) oilist. 60

61 PIM SSM Pruning - IOS /2 Source Data Source Tree Src / (S,G) Prune 3 Rcvr /0 /1 B A / /0 C /1 Rcvr2 ( , ), 00:43:26/00:02:49, flags: sti stp Incoming interface: Ethernet0/0, RPF nbr Ethernet0/1, Forward/Sparse, 00:00:14/00:02:45 3 B s (S,G) oilist now empty; triggers (S,G) Prune toward source. 61

62 PIM SSM Pruning - IOS /2 Source Data Source Tree Src Rcvr1 / /0 /1 4 B A / /0 C /1 Rcvr2 ( , ), 00:43:44/00:02:49, 00:00:15/00:02:49, flags: st Incoming interface: Ethernet0/2, RPF nbr Ethernet0/1, Ethernet0/0, Forward/Sparse, 00:00:03/00:02:48 00:28:03/00:02:43 Ethernet0/1, Forward/Sparse, 00:00:03/00:02:48 4 A removes /0 from (S,G) oilist. 62

63 PIM SSM Pruning - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 IGMP Leave 5 Rcvr2 5 C is a Leaf router. Last Rcvr, leaves (S,G). 63

64 PIM SSM Pruning - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C 6 /1 Rcvr2 ( , ), 00:43:45/00:02:49, flags: stp sti Incoming interface: Ethernet0/0, RPF nbr Ethernet0/1, Forward/Sparse, 00:00:02/00:02:49 6 C removes /1 from (S,G) oilist. 64

65 PIM SSM Pruning - IOS /2 Source Data Source Tree Src Rcvr1 / /0 /1 B A / (S,G) Prune /0 C /1 Rcvr2 7 C s (S,G) oilist now empty; triggers (S,G) Prune toward source. 65

66 PIM SSM Pruning - IOS /2 Source Data Source Tree Src Rcvr1 / /0 /1 B A / /0 C /1 Rcvr2 ( , ), 00:43:46/00:02:49, flags: stp Incoming interface: Ethernet0/2, RPF nbr Ethernet0/1, Forward/Sparse, 00:00:03/00:02:48 8 A removes /1 from (S,G) oilist. 66

67 PIM SSM Pruning - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 Rcvr2 ( , ), 00:43:48/00:00:00, 00:43:48/00:00:04, 00:43:48/00:00:02, 00:43:48/00:00:03, 00:43:48/00:00:01, flags: stp Incoming interface: Ethernet0/0, RPF nbr After about 3 minutes... 67

68 PIM SSM Pruning - IOS /2 Source Data Src / A / Source Tree Rcvr /0 /1 B /0 C /1 Rcvr2 ( , ), 00:43:48/00:00:00, flags: stp Incoming interface: Ethernet0/0, RPF nbr After about 3 minutes... Same for routers C and A (S, G) State times out 68

69 PIM Any-Source Multicast (ASM) 69

70 PIM ASM Joining 70

71 PIM ASM Joining - IOS Shared Tree To RP ( ) A IGMP Join Rcvr E1 B 1 Rcvr wishes to receive group G traffic. Sends IGMP Join for G. 71

72 PIM ASM Joining - IOS Shared Tree To RP ( ) Rcvr E1 B A (*, ), 00:00:05/00:00:00, RP , flags: SC Incoming interface: Ethernet0, RPF nbr Ethernet1, Forward/Sparse-Dense, 00:00:05/00:02:54 B Creates (*, ) State 72

73 PIM ASM Joining - IOS Shared Tree To RP ( ) A Rcvr E1 B 2 (*,G) Join 1 Rcvr wishes to receive group G traffic. Sends IGMP Join for G. 2 B sends (*,G) Join towards RP. 73

74 PIM ASM Joining - IOS Shared Tree To RP ( ) Rcvr E1 B A (*, ), 00:00:05/00:00:00, RP , flags: S Incoming interface: Serial0, RPF nbr Ethernet0, Forward/Sparse-Dense, 00:00:05/00:02:54 A Creates (*, ) State 74

75 PIM ASM Joining - IOS To RP ( ) 4 Shared Tree Shared Tree 3 (*,G) Join A Rcvr E1 B 1 Rcvr wishes to receive group G traffic. Sends IGMP Join for G. 2 B sends (*,G) Join towards RP. 3 A sends (*,G) Join towards RP. 4 Shared tree is built all the way back to the RP. 75

76 PIM ASM Registering 76

77 PIM ASM Register Scenarios Receivers Join Group First Source Registers First Receivers along the SPT 77

78 PIM ASM Registering Receiver Joins First 78

79 PIM ASM Registering - IOS Receiver Joins Group First RP A B S3 C Shared Tree (*, ), 00:03:14/00:00:00, RP , flags:s Incoming interface: Null, RPF nbr , Serial0, Forward/Sparse-Dense, 00:03:14/00:03:15 Serial1, Forward/Sparse-Dense, 00:03:14/00:03:15 State in RP Before Any Source Registers (With Receivers on Shared Tree) 79

80 PIM ASM Registering - IOS Receiver Joins Group First RP A B C S3 Shared Tree rtr-b>sh ip mroute No such group State in B Before Any Source Registers (With Receivers on Shared Tree) 80

81 PIM ASM Registering - IOS Receiver Joins Group First RP A B C S3 Shared Tree rtr-a>sh ip mroute No such group. State in A Before Any Source Registers (With Receivers on Shared Tree) 81

82 PIM ASM Registering - IOS Receiver Joins Group First ( , ) Mcast Packets Source RP A B C S3 Shared Tree 1 Source begins sending group G traffic. 82

83 PIM ASM Registering - IOS Receiver Joins Group First ( , ) Mcast Packets Source Register Msgs A B C S3 RP (*, ), 00:00:03/00:00:00, RP , flags: SP Incoming interface: Serial0, RPF nbr , Null ( , ), 00:00:03/00:02:56, flags: FPT Incoming interface: Ethernet0, RPF nbr , Registering Null A Creates (S, G) State for Source (After Automatically Creating a (*, G) entry) 1 Source begins sending group G traffic. Shared Tree 2 A encapsulates packets in Registers; unicasts to RP. 83

84 PIM ASM Registering - IOS Receiver Joins Group First ( , ) Mcast Packets Source Register Msgs A B C (*, ), 00:09:21/00:00:00, RP , flags: S Incoming interface: Null, RPF nbr , Serial0, Forward/Sparse-Dense, 00:09:21/00:02:38 Serial1, Forward/Sparse-Dense, 00:03:14/00:02:46 ( , , 00:01:15/00:02:46, flags: Incoming interface: Serial3, RPF nbr , Serial0, Forward/Sparse-Dense, 00:00:49/00:02:11 Serial1, Forward/Sparse-Dense, 00:00:49/00:02:11 S3 RP 3 (*, ) Mcast Traffic Shared Tree RP Processes Register; Creates (S, G) State 3 RP (C) de-encapsulates packets; forwards down Shared tree. 84

85 PIM ASM Registering Receiver Joins Group First ( , ) Mcast Packets Source Register Msgs (S,G) Join 4 A B C S3 Shared Tree RP (*, ) Mcast Traffic 4 RP sends (S,G) Join toward Source to build SPT. 85

86 PIM ASM Registering - IOS Receiver Joins Group First ( , ) Mcast Packets Source (S,G) Join 5 Register Msgs A B C S3 Shared Tree RP (*, ) Mcast Traffic (*, ), 00:04:28/00:00:00, RP , flags: SP Incoming interface: Serial1, RPF nbr , Null ( , ), 00:04:28/00:01:32, flags: Incoming interface: Serial0, RPF nbr Serial1, Forward/Sparse-Dense, 00:04:28/00:01:32 B Processes Join, Creates (S, G) State (After Automatically Creating the (*, G) Entry) 5 B sends (S,G) Join toward Source to continue building SPT. 86

87 PIM ASM Registering - IOS Receiver Joins Group First ( , ) Mcast Packets Source Register Msgs A B C S3 Shared Tree RP (*, ) Mcast Traffic (*, ), 00:04:28/00:00:00, RP , flags: SP Incoming interface: Serial0, RPF nbr , Null ( , ), 00:04:28/00:01:32, flags: FT Incoming interface: Ethernet0, RPF nbr , Registering Serial0, Forward/Sparse-Dense, 00:04:28/00:01:32 A Processes the (S, G) Join; Adds Serial0 to OIL 87

88 PIM ASM Registering Receiver Joins Group First ( , ) Mcast Packets Source Register Msgs A B C S3 Shared Tree RP (*, ) Mcast Traffic 6 RP begins receiving (S,G) traffic down SPT. 88

89 PIM ASM Registering - IOS Receiver Joins Group First ( , ) Mcast Packets Source Register Msgs A B C S3 Shared Tree (*, ), 00:09:21/00:00:00, RP , flags: S Incoming interface: Null, RPF nbr , Serial0, Forward/Sparse-Dense, 00:09:21/00:02:38 Serial1, Forward/Sparse-Dense, 00:03:14/00:02:46 RP (*, ) Mcast Traffic ( , , 00:01:15/00:02:46, flags:t Incoming interface: Serial3, RPF nbr , Serial0, Forward/Sparse-Dense, 00:00:49/00:02:11 Serial1, Forward/Sparse-Dense, 00:00:49/00:02:11 Note T Flag Is Now Set Traffic Arriving via SPT Is Forwarded Down Shared Tree (This Causes the T Flag to Be Set) 89

90 PIM ASM Registering - IOS Receiver Joins Group First ( , ) Mcast Packets Source Register Msgs A B C Register-Stop S3 Shared Tree RP (*, ) Mcast Traffic 7 Once T Flag is set, next Register causes RP to send back a Register-Stop to A 90

91 PIM ASM Registering - IOS Receiver Joins Group First ( , ) Mcast Packets Source Register Msgs A B C Register-Stop S3 (*, ), 00:04:28/00:00:00, RP , flags: SP Incoming interface: Serial0, RPF nbr , Null ( , ), 00:04:28/00:01:32, flags: FT Incoming interface: Ethernet0, RPF nbr , Registering Serial0, Forward/Sparse-Dense, 00:04:28/00:01:32 A Stops Sending Register Messages (Final State in A) Shared Tree 8 (S,G) Traffic now flowing down a single path (SPT) to RP. RP (*, ) Mcast Traffic 91

92 PIM ASM Registering - IOS Receiver Joins Group First ( , ) Mcast Packets Source A B C S3 Shared Tree RP (*, ) Mcast Traffic (*, ), 00:04:28/00:00:00, RP , flags: SP Incoming interface: Serial1, RPF nbr , Null ( , ), 00:04:28/00:01:32, flags: T Incoming interface: Serial0, RPF nbr Serial1, Forward/Sparse-Dense, 00:04:28/00:01:32 Final State in B 92

93 PIM ASM Registering - IOS Receiver Joins Group First ( , ) Mcast Packets Source A B C (*, ), 00:09:21/00:00:00, RP , flags: S Incoming interface: Null, RPF nbr , Serial0, Forward/Sparse-Dense, 00:09:21/00:02:38 Serial1, Forward/Sparse-Dense, 00:03:14/00:02:46 ( , , 00:01:15/00:02:46, flags: T Incoming interface: Serial3, RPF nbr , Serial0, Forward/Sparse-Dense, 00:00:49/00:02:11 Serial1, Forward/Sparse-Dense, 00:00:49/00:02:11 Final State in the RP (With Receivers on Shared Tree) S3 Shared Tree RP (*, ) Mcast Traffic 93

94 PIM ASM Registering Source Registers First 94

95 PIM ASM Registering - IOS Source Registers First RP A B S3 C rtr-c>show ip mroute Group not found. State in RP before Registering (Without Receivers on Shared Tree) 95

96 PIM ASM Registering - IOS Source Registers First RP A B S3 C rtr-b>show ip mroute Group not found. State in B Before Any Source Registers (With Receivers on Shared Tree) 96

97 PIM ASM Registering - IOS Source Registers First RP A B S3 C rtr-a>show ip mroute Group not found. State in A Before Any Source Registers (With Receivers on Shared Tree) 97

98 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets 1 Source A B S3 C RP 1 Source begins sending group G traffic. 98

99 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets Source Register Msgs A B S3 C RP (*, ), 00:00:03/00:00:00, RP , flags: SP Incoming interface: Serial0, RPF nbr , Null ( , ), 00:00:03/00:02:56, flags: FPT Incoming interface: Ethernet0, RPF nbr , Registering Null A Creates (S, G) State for Source (After Automatically Creating a (*, G) Entry) 1 Source begins sending group G traffic. 2 A encapsulates packets in Registers; unicasts to RP. 99

100 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets Source Register Msgs A B S3 C RP 3 (*, ), 00:01:15/00:00:00, RP , flags: SP Incoming interface: Null, RPF nbr , Null ( , ), 00:01:15/00:01:45, flags: P Incoming interface: Serial3, RPF nbr , Null RP Processes Register; Creates (S, G) State (After Automatically Creating the (*, G) Entry) 3 RP (C) has no receivers on Shared Tree; discards packet. 100

101 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets Source Register Msgs A B S3 C RP 4 Register-Stop 4 RP sends Register-Stop to A. 101

102 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets Source A B S3 C 5 RP 5 A stops encapsulating traffic in Register Messages; drops packets from Source. 102

103 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets Source A B S3 C RP (*, ), 00:01:28/00:00:00, RP , flags: SP Incoming interface: Serial0, RPF nbr , Null ( , ), 00:01:28/00:01:32, flags: FPT Incoming interface: Ethernet0, RPF nbr Null State in A After Registering (Without Receivers on Shared Tree) 103

104 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets Source A B S3 C RP rtr-b>show ip mroute Group not found. State in B after A Registers (Without Receivers on Shared Tree) 104

105 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets Source A B S3 C RP (*, ), 00:01:15/00:00:00, RP , flags: SP Incoming interface: Null, RPF nbr , Null ( , ), 00:01:15/00:01:45, flags: P Incoming interface: Serial3, RPF nbr , Null State in RP After A Registers (Without Receivers on Shared Tree) 105

106 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets Source A B S3 C RP 6 (*, G) Join 6 RP (C) receives (*, G) Join from a receiver on Shared Tree. 106

107 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets Source (S, G) Join A B S3 C RP (*, ), 00:09:21/00:00:00, RP , flags: S Incoming interface: Null, RPF nbr , Serial1, Forward/Sparse-Dense, 00:00:14/00:02:46 ( , , 00:01:15/00:02:46, flags: T Incoming interface: Serial3, RPF nbr , Serial1, Forward/Sparse-Dense, 00:00:14/00:02:46 RP Processes (*,G) Join (Adds Serial1 to Outgoing Interface Lists) 7 RP sends (S,G) Joins for all known Sources in Group. 107

108 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets Source (S, G) Join A B S3 C RP (*, ), 00:04:28/00:00:00, RP , flags: SP Incoming interface: Serial1, RPF nbr , Null ( , ), 00:04:28/00:01:32, flags: Incoming interface: Serial0, RPF nbr Serial1, Forward/Sparse-Dense, 00:04:28/00:01:32 B Processes Join, Creates (S, G) State (After Automatically Creating the (*, G) Entry) 8 B sends (S,G) Join toward Source to continue building SPT. 108

109 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets Source A B S3 C (*, ), 00:04:28/00:00:00, RP , flags: SP Incoming interface: Serial0, RPF nbr , Null ( , ), 00:04:28/00:01:32, flags: FT Incoming interface: Ethernet0, RPF nbr , Serial0, Forward/Sparse-Dense, 00:04:28/00:01:32 RP 10 (*, ) Mcast Traffic A Processes the (S, G) Join; Adds Serial0 to OIL 9 RP begins receiving (S,G) traffic down SPT. 10 RP forwards (S,G) traffic down Shared Tree to receivers. 109

110 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets Source A B S3 C RP (*, ) Mcast Traffic (*, ), 00:04:28/00:00:00, RP , flags: SP Incoming interface: Serial0, RPF nbr , Null ( , ), 00:04:28/00:01:32, flags: FT Incoming interface: Ethernet0, RPF nbr , Serial1, Forward/Sparse-Dense, 00:04:28/00:01:32 Final state in Router A 110

111 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets Source A B S3 C RP (*, ) Mcast Traffic (*, ), 00:04:28/00:00:00, RP , flags: SP Incoming interface: Serial1, RPF nbr , Null ( , ), 00:04:28/00:01:32, flags: T Incoming interface: Serial0, RPF nbr Serial1, Forward/Sparse-Dense, 00:04:28/00:01:32 Final State in B After Receivers Join 111

112 PIM ASM Registering - IOS Source Registers First ( , ) Mcast Packets Source A B S3 C (*, ), 00:09:21/00:00:00, RP , flags: S Incoming interface: Null, RPF nbr , Serial1, Forward/Sparse-Dense, 00:03:14/00:02:46 RP (*, ) Mcast Traffic ( , , 00:01:15/00:02:46, flags: T Incoming interface: Serial3, RPF nbr , Serial1, Forward/Sparse-Dense, 00:00:49/00:02:11 Final State in RP After Receivers Join 112

113 PIM ASM Registering Receiver Along the SPT 113

114 PIM ASM Registering - IOS Receivers Along the SPT ( , ) Mcast Packets Shared Tree RP Source A B S3 C (*, ) Mcast Traffic (*, ), 00:04:28/00:00:00, RP , flags: SP Incoming interface: Serial0, RPF nbr , Null ( , ), 00:04:28/00:01:32, flags: FT Incoming interface: Ethernet0, RPF nbr , Serial1, Forward/Sparse-Dense, 00:04:28/00:01:32 Current state in Router A 114

115 PIM ASM Registering - IOS Receivers Along the SPT ( , ) Mcast Packets Source A (*, ), 00:04:28/00:00:00, RP , flags: SP Incoming interface: Serial1, RPF nbr , Null B S3 C RP Shared Tree (*, ) Mcast Traffic ( , ), 00:04:28/00:01:32, flags: T Incoming interface: Serial0, RPF nbr Serial1, Forward/Sparse-Dense, 00:04:28/00:01:32 Current State in B 115

116 PIM ASM Registering - IOS Receivers Along the SPT ( , ) Mcast Packets Shared Tree RP Source A B S3 C (*, ) Mcast Traffic (*, ), 00:09:21/00:00:00, RP , flags: S Incoming interface: Null, RPF nbr , Serial1, Forward/Sparse-Dense, 00:03:14/00:02:46 ( , , 00:01:15/00:02:46, flags: T Incoming interface: Serial3, RPF nbr , Serial1, Forward/Sparse-Dense, 00:00:49/00:02:11 Current State in the RP 116

117 PIM ASM Registering - IOS Receivers Along the SPT ( , ) Mcast Packets Shared Tree RP Source A 1 IGMP Join B S3 C (*, ) Mcast Traffic Rcvr 1 Rcvr wishes to receive group G traffic. Sends IGMP Join for G. 117

118 PIM ASM Registering - IOS Receivers Along the SPT ( , ) Mcast Packets Shared Tree RP Source A B S3 2 C (*, ) Mcast Traffic Rcvr (*, ), 00:04:28/00:00:00, RP , flags: SC Incoming interface: Serial1, RPF nbr , Ethernet0, Forward/Sparse-Dense, 00:00:30/00:02:30 ( , ), 00:04:28/00:01:32, flags: CT Incoming interface: Serial0, RPF nbr Serial1, Forward/Sparse-Dense, 00:04:28/00:01:32 Ethernet0, Forward/Sparse-Dense, 00:00:30/00:02:30 B adds Ethernet0 to (*,G) and (S,G) OIL s 2 Traffic begins flowing to Rcvr via (S,G) 118

119 PIM ASM Registering - IOS Receivers Along the SPT ( , ) Mcast Packets Shared Tree RP Source A B S3 2 (*, G) Join C (*, ) Mcast Traffic Rcvr 3 B triggers a (*,G) Join to join the Shared Tree 119

120 PIM ASM Registering - IOS Receivers Along the SPT ( , ) Mcast Packets Source S3 A B C RP Shared Tree (*, ) Mcast Traffic Rcvr (*, ), 00:09:21/00:00:00, RP , flags: S Incoming interface: Null, RPF nbr , Serial1, Forward/Sparse-Dense, 00:03:14/00:02:46 Serial3, Forward/Sparse-Dense, 00:00:10/00:02:50 ( , , 00:01:15/00:02:46, flags: T Incoming interface: Serial3, RPF nbr , Serial1, Forward/Sparse-Dense, 00:00:49/00:02:11 Pop Quiz: Why didn t it copy Serial3 to the OIL of the (S,G) entry? RP adds Serial3 to (*,G) OIL 120

121 PIM ASM Registering - IOS Receivers Along the SPT ( , ) Mcast Packets Source S3 A B C RP Shared Tree (*, ) Mcast Traffic Rcvr 4 Other Group G traffic can now flow to Rcvr via Shared Tree. (Note: traffic doesn t flow to RP then back down to B) 121

122 PIM ASM SPT Switchover 122

123 PIM ASM SPT-Switchover - IOS SPT Thresholds may be set for any Group Access Lists may be used to specify which Groups Default Threshold = 0kbps (I.e. immediately join SPT) Threshold = infinity means never join SPT Don t use values in between 0 and infinity (In IOS XR, 0 and infinity are the only options) Threshold triggers Join of Source Tree Sends an (S,G) Join up SPT for next S in G packet received 123

124 PIM ASM SPT-Switchover - IOS To RP ( ) D Rcvr B S2 C Rcvr A To Source S i E1 B (*, ), 00:01:43/00:02:13, RP , flags: S Incoming interface: Serial0, RPF nbr , Serial1, Forward/Sparse-Dense, 00:01:43/00:02:11 Serial2, Forward/Sparse-Dense, 00:00:32/00:02:28 A State in C Before Switch Shared Tree 124

125 PIM ASM SPT-Switchover - IOS To RP ( ) D S2 C Rcvr A To Source S i E1 B A Shared Tree Rcvr B (*, ), 00:01:43/00:02:13, RP , flags: SC Incoming interface: Serial0, RPF nbr , Ethernet0, Forward/Sparse-Dense, 00:01:43/00:02:11 State in D Before Switch 125

126 PIM ASM SPT-Switchover - IOS To RP ( ) D Rcvr B S2 C Rcvr A To Source S i E1 B A Shared Tree (*, ), 00:01:43/00:02:13, RP , flags: S Incoming interface: Serial0, RPF nbr , Ethernet0, Forward/Sparse-Dense, 00:01:43/00:02:11 State in A Before Switch 126

127 PIM ASM SPT-Switchover - IOS To RP ( ) D Rcvr B S2 C Rcvr A To Source S i E1 B A (*, ), 00:01:43/00:02:13, RP , flags: SCJJ Incoming interface: Ethernet0, RPF nbr , Ethernet1, Forward/Sparse-Dense, 00:01:43/00:02:11 State in B Before Switch Shared Tree Note J Flag is set 127

128 PIM ASM SPT-Switchover - IOS To RP ( ) D Rcvr B S2 C Rcvr A To Source S i E1 B A (*, ), 00:01:43/00:02:13, RP , flags: SCJ Incoming interface: Ethernet0, RPF nbr , Ethernet1, Forward/Sparse-Dense, 00:01:43/00:02:11 1 (S i, G) Traffic Flow Shared Tree Flow 1 New source (S i,g) packet arrives down Shared tree. 128

129 PIM ASM SPT-Switchover - IOS To RP ( ) D Rcvr B S2 C Rcvr A To Source S i E1 B A (*, ), 00:01:43/00:02:13, 00:01:43/00:00:00, RP , flags: SCJ Incoming interface: Ethernet0, RPF nbr , Ethernet1, Forward/Sparse-Dense, 00:01:43/00:02:11 (S i, G) Traffic Flow Shared Tree Flow ( , ), 00:00:28/00:02:51, flags: CJ Incoming interface: Ethernet0, RPF nbr Ethernet1, Forward/Sparse-Dense, 00:00:28/00:02: Because of C bit, B creates (S i,g) state to cut over to SPT. 129

130 PIM ASM SPT-Switchover - IOS To RP ( ) D S2 C Rcvr A To Source S i E1 B A (S i,g) Join (S i, G) Traffic Flow Shared Tree Flow Rcvr B 3 B sends (S i,g) Join towards S i. 130

131 PIM ASM SPT-Switchover - IOS To RP ( ) D Rcvr B S2 C Rcvr A To Source S i E (*, ), 00:01:43/00:00:00, RP , flags: S Incoming interface: Serial0, RPF nbr , Ethernet0, Forward/Sparse-Dense, 00:01:43/00:02:11 ( , ), 00:13:28/00:02:53, flags: Incoming interface: Serial1, RPF nbr Ethernet0, Forward/Sparse-Dense, 00:13:25/00:02:30 B A A creates (S i,g) state (S i, G) Traffic Flow Shared Tree Flow 131

132 PIM ASM SPT-Switchover - IOS To RP ( ) D S2 C Rcvr A To Source S i E1 B A (Si,G) Join (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow Rcvr B 4 A triggers (S i,g) Join toward S i. 132

133 PIM ASM SPT-Switchover - IOS To RP ( ) D S2 C Rcvr A To Source S i E1 B A (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow Rcvr B 4 A triggers (S i,g) Join toward S i. 5 (S i, G) traffic begins flowing down SPT tree instead of Shared Tree. 133

134 PIM ASM SPT-Switchover - IOS To RP ( ) D S2 C Rcvr A To Source S i E1 B A (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow Rcvr B (*, ), 00:01:43/00:00:00, RP , flags: S Incoming interface: Serial0, RPF nbr , Ethernet0, Forward/Sparse-Dense, 00:01:43/00:02:11 ( , ), 00:13:28/00:02:53, flags: T Incoming interface: Serial1, RPF nbr Ethernet0, Forward/Sparse-Dense, 00:13:25/00:02:30 T Flag Set by Arriving Traffic on SPT 134

135 PIM ASM SPT-Switchover - IOS To RP ( ) D S2 C Rcvr A 6 (S i,g)rp-bit To Source S Prune i E1 B A (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow Rcvr B (*, ), 00:01:43/00:00:00, RP , flags: S Incoming interface: Serial0, RPF nbr , Ethernet0, Forward/Sparse-Dense, 00:01:43/00:02:11 ( , ), 00:13:28/00:02:53, flags: Incoming interface: Serial1, RPF nbr Ethernet0, Forward/Sparse-Dense, 00:13:25/00:02:30 Note RPF Info Does Not Match. This Indicates SPT and RPT Diverge. 6 Once T Flag is set, A triggers (S i,g)rp-bit Prunes toward RP. 135

136 PIM ASM SPT-Switchover - IOS To RP ( ) D Rcvr B S2 C Rcvr A To Source S i E1 B (*, ), 00:01:43/00:00:00, RP , flags: S Incoming interface: Serial0, RPF nbr , Serial1, Forward/Sparse-Dense, 00:01:43/00:02:11 Serial2, Forward/Sparse-Dense, 00:00:32/00:02:28 ( , ), 00:13:28/00:02:53, flags: R Incoming interface: Serial0, RPF nbr Serial2, Forward/Sparse-Dense, 00:00:32/00:02:28 C creates (S i, G) RP-bit State and removes Serial1 from (S i, G) A (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow Note: Because R bit is set, Incoming interface points to RP not Source. 136

137 PIM ASM SPT-Switchover - IOS To RP ( ) D S2 C Rcvr A To Source S i E1 B A (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow Rcvr B 7 Unnecessary (S i, G) traffic is pruned from the Shared tree. 137

138 PIM ASM SPT-Switchover - IOS To RP ( ) D S2 C Rcvr A To Source S i E1 B A (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow Rcvr B (*, ), 00:01:43/00:00:00, RP , flags: SCJ Incoming interface: Serial0, RPF nbr , Ethernet0, Forward/Sparse-Dense, 00:01:43/00:02:11 ( , ), 00:00:28/00:02:51, flags: CJ Incoming interface: Serial0, RPF nbr Ethernet0, Forward/Sparse-Dense, 00:00:28/00:02:32 8 Because of C bit, D also creates (S i,g) state to cut over to SPT. 138

139 PIM ASM SPT-Switchover - IOS To RP ( ) D Rcvr B 9 S2 C (Si,G) Join Rcvr A To Source S i E1 B A (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow 9 D triggers (S i,g) Join toward S i. 139

140 PIM ASM SPT-Switchover - IOS To RP ( ) D Rcvr B S2 C Rcvr A To Source S i E1 B (*, ), 00:01:43/00:00:00, RP , flags: S Incoming interface: Serial0, RPF nbr , Serial1, Forward/Sparse-Dense, 00:01:43/00:02:11 Serial2, Forward/Sparse-Dense, 00:00:32/00:02:28 ( , ), 00:13:28/00:02:53, flags: R Incoming interface: Serial1, Serial0, RPF nbr Serial2, Forward/Sparse-Dense, 00:00:32/00:02:28 C resets (S i, G) RP-bit State and RPF s (S i, G) toward Source. A (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow 140

141 PIM ASM SPT-Switchover - IOS To RP ( ) D S2 C Rcvr A To Source S i 10 (Si,G) Join E1 B A (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow Rcvr B 10 C triggers (S i,g) Join toward S i. 141

142 PIM ASM SPT-Switchover - IOS To RP ( ) D Rcvr B S2 C Rcvr A To Source S i E (*, ), 00:01:43/00:00:00, RP , flags: S Incoming interface: Serial0, RPF nbr , Ethernet0, Forward/Sparse-Dense, 00:01:43/00:02:11 ( , ), 00:13:28/00:02:53, flags: Incoming interface: Serial1, RPF nbr Ethernet0, Forward/Sparse-Dense, 00:13:25/00:02:30 Serial0, Forward/Sparse-Dense, 00:13:25/00:02:30 A adds Serial0 to (S i,g) OIL B A (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow 142

143 PIM ASM SPT-Switchover - IOS To RP ( ) D S2 C Rcvr A To Source S i E1 B A (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow Rcvr B Traffic flows to Rcvr B via SPT. 143

144 PIM ASM SPT-Switchover - IOS 11 (S i,g)rp-bit Prune To RP ( ) D S2 C Rcvr A To Source S i E1 B A (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow Rcvr B (*, ), 00:01:43/00:00:00, RP , flags: S Incoming interface: Serial0, RPF nbr , Serial1, Forward/Sparse-Dense, 00:01:43/00:02:11 Serial2, Forward/Sparse-Dense, 00:00:32/00:02:28 ( , ), 00:13:28/00:02:53, flags:t Incoming interface: Serial1, RPF nbr Serial2, Forward/Sparse-Dense, 00:00:32/00:02:28 Note RPF Info Does Not Match. This Indicates SPT and RPT Diverge. 11 Once T Flag is set, C triggers (S i,g)rp-bit Prunes toward RP. 144

145 PIM ASM SPT-Switchover - IOS To RP ( ) D S2 C Rcvr A To Source S i E1 B A (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow Rcvr B All (S i,g) Traffic pruned from Shared Tree. 145

146 PIM ASM SPT-Switchover - IOS To RP ( ) D S2 C Rcvr A To Source S i E1 B A Shared Tree (S i, G) Traffic Flow Shared Tree Flow SPT Tree Flow Rcvr B But what does the Shared Tree look like now? Don t confuse Forwarding State with Tree Topology! 146

147 PIM ASM Pruning 147

148 PIM ASM Pruning - IOS Shared Tree Case To RP ( ) (S i, G) Traffic Flow Shared Tree SPT Tree Rcvr A E1 B A (*, ), 00:01:43/00:02:13, RP , flags: SC Incoming interface: Ethernet0, RPF nbr , Ethernet1, Forward/Sparse-Dense, 00:01:43/00:02:11 State in B Before Pruning 148

149 PIM ASM Pruning - IOS Shared Tree Case To RP ( ) (S i, G) Traffic Flow Shared Tree SPT Tree Rcvr A E1 B A (*, ), 00:01:43/00:02:13, RP , flags: S Incoming interface: Serial0, RPF nbr , Ethernet0, Forward/Sparse-Dense, 00:01:43/00:02:11 State in A Before Pruning 149

150 PIM ASM Pruning - IOS Shared Tree Case To RP ( ) (S i, G) Traffic Flow Shared Tree SPT Tree 1 IGMP Leave Rcvr A E1 B A B is a Leaf router. Last Rcvr, leaves group G. 150

151 PIM ASM Pruning - IOS Shared Tree Case To RP ( ) (S i, G) Traffic Flow Shared Tree SPT Tree E1 2 B A (*, ), 00:01:43/00:02:13, RP , flags: SP Incoming interface: Ethernet0, RPF nbr , Ethernet1, Forward/Sparse-Dense, 00:01:43/00:02:11 2 B removes Ethernet1 from (*,G) and any (S i,g) oilists. 151

152 PIM ASM Pruning - IOS Shared Tree Case To RP ( ) (S i, G) Traffic Flow Shared Tree SPT Tree E1 B A (*,G) Prune (*, ), 00:01:43/00:02:13, RP , flags: SP Incoming interface: Ethernet0, RPF nbr , 2 B removes Ethernet1 from (*,G) and any (S i,g) oilists. 3 B s (*,G) oilist now empty; triggers (*,G) Prune toward RP. 152

153 PIM ASM Pruning - IOS Shared Tree Case To RP ( ) (S i, G) Traffic Flow Shared Tree SPT Tree E1 B A (*, ), 00:01:43/00:02:13, RP , flags: S P Incoming interface: Serial0, RPF nbr , Ethernet0, Forward/Sparse-Dense, 00:01:43/00:02:11 4 A receives Prune; removes from (*,G) oilist. (After the 3 second Multi-access Network Prune delay.) 153

154 PIM ASM Pruning - IOS Shared Tree Case To RP ( ) (*,G) Prune (S 5 i, G) Traffic Flow Shared Tree SPT Tree E1 B A (*, ), 00:01:43/00:02:13, RP , flags: SP Incoming interface: Serial0, RPF nbr , 4 A receives Prune; removes from (*,G) oilist. (After the 3 second Multi-access Network Prune delay.) 5 A s (*,G) oilist now empty; triggers (*,G) Prune toward RP. 154

155 PIM ASM Pruning - IOS Shared Tree Case To RP ( ) (S i, G) Traffic Flow Shared Tree A SPT Tree E1 B Pruning continues back toward RP. 155

156 PIM ASM Pruning - IOS Source (SPT) Case To RP ( ) To Source S i Shared Tree (S i, G) Traffic Flow SPT Tree A Rcvr E1 B (*, ), 00:01:43/00:00:00, RP , flags: S Incoming interface: Serial0, RPF nbr , Ethernet0, Forward/Sparse-Dense, 00:01:43/00:02:11 ( , ), 00:01:05/00:01:55, flags: T Incoming interface: Serial1, RPF nbr Ethernet0, Forward/Sparse-Dense, 00:01:05/00:02:55 State in A Before Pruning 156

157 PIM ASM Pruning - IOS Source (SPT) Case To RP ( ) To Source S i Shared Tree (S i, G) Traffic Flow SPT Tree A Rcvr E1 B (*, ), 00:01:43/00:00:00, RP , flags: SC Incoming interface: Ethernet0, RPF nbr , Ethernet1, Forward/Sparse-Dense, 00:01:43/00:02:11 ( , ), 00:01:05/00:01:55, flags: CJT Incoming interface: Ethernet0, RPF nbr Ethernet1, Forward/Sparse-Dense, 00:01:05/00:02:55 State in B Before Pruning 157

158 PIM ASM Pruning - IOS Source (SPT) Case To RP ( ) To Source S i Shared Tree (S i, G) Traffic Flow SPT Tree A IGMP Leave Rcvr E1 B (*, ), 00:01:43/00:00:00, RP , flags: SC Incoming interface: Ethernet0, RPF nbr , Ethernet1, Forward/Sparse-Dense, 00:01:43/00:02:11 ( , ), 00:01:05/00:01:55, flags: CJT Incoming interface: Ethernet0, RPF nbr Ethernet1, Forward/Sparse-Dense, 00:01:05/00:02:55 1 B is a Leaf router. Last Rcvr leaves group G. 158

159 PIM ASM Pruning - IOS Source (SPT) Case To RP ( ) To Source S i Shared Tree (S i, G) Traffic Flow SPT Tree A E1 2 B (*, ), 00:01:43/00:00:00, RP , flags: SCP Incoming interface: Ethernet0, RPF nbr , Ethernet1, Forward/Sparse-Dense, 00:01:43/00:02:11 ( , ), 00:01:05/00:01:55, flags: CJT Incoming interface: Ethernet0, RPF nbr Ethernet1, Forward/Sparse-Dense, 00:01:05/00:02:55 2 B removes Ethernet1 from (*,G) and all (S,G) OIL s. 159

160 PIM ASM Pruning - IOS Source (SPT) Case To RP ( ) To Source S i Shared Tree (S i, G) Traffic Flow SPT Tree (*,G) Prune 3 A E1 B (*, ), 00:01:43/00:00:00, RP , flags: SCP Incoming interface: Ethernet0, RPF nbr , ( , ), 00:01:05/00:01:55, flags: CJPT Incoming interface: Ethernet0, RPF nbr B s (*,G) OIL now empty; triggers (*,G) Prune toward RP. 160

161 PIM ASM Pruning - IOS Source (SPT) Case To RP ( ) To Source S i Shared Tree (S i, G) Traffic Flow SPT Tree (S,G) Prune 4 A E1 B (*, ), 00:01:43/00:00:00, RP , flags: SCP Incoming interface: Ethernet0, RPF nbr , ( , ), 00:01:05/00:01:55, flags: CJPT Incoming interface: Ethernet0, RPF nbr B s (S,G) OIL also now empty; triggers (S, G) Prune towards Si. 161

162 PIM ASM Pruning - IOS Source (SPT) Case To RP ( ) To Source S i Shared Tree (S i, G) Traffic Flow SPT Tree A E1 B (*, ), 00:01:43/00:00:00, RP , flags: S P Incoming interface: Serial0, RPF nbr , Ethernet0, Forward/Sparse-Dense, 00:01:43/00:02:11 ( , ), 00:01:05/00:01:55, flags: PT T Incoming interface: Serial1, RPF nbr Ethernet0, Forward/Sparse-Dense, 00:01:05/00:02:55 5 After A receives (*, G) Prune; removes from (*,G) & (S,G) OIL s (After the 3 second Multi-access Network Prune delay.) 162

163 PIM ASM Pruning - IOS Source (SPT) Case To RP ( ) To Source S i Shared Tree (S i, G) Traffic Flow SPT Tree (*,G) Prune A E1 B (*, ), 00:02:32/00:00:00, RP , flags: SP Incoming interface: Serial0, RPF nbr , ( , ), 00:01:56/00:00:53, flags: PT Incoming interface: Serial1, RPF nbr A s (*,G) OIL now empty; triggers (*,G) Prune toward RP. 163

164 PIM ASM Pruning - IOS Source (SPT) Case To RP ( ) To Source S i (S i, G) Traffic Flow SPT Tree A (S i,g) Prune E1 B (*, ), 00:02:32/00:00:00, RP , flags: SP Incoming interface: Serial0, RPF nbr , ( , ), 00:01:56/00:00:53, flags: PT Incoming interface: Serial1, RPF nbr A s (S,G) OIL also now empty; triggers (S,G) Prune towards S i. 164

165 PIM ASM Pruning - IOS Source (SPT) Case To RP ( ) 8 To Source S i A E1 B (*, ), 00:02:32/00:00:00, RP , flags: SP Incoming interface: Serial0, RPF nbr , ( , ), 00:01:56/00:00:53, flags: PT Incoming interface: Serial1, RPF nbr (S i,g) traffic ceases flowing down SPT. 165

166 PIM ASM Pruning - IOS Source (SPT) Case To RP ( ) To Source S i A E1 B (*, ), 00:02:32/00:00:00, RP , flags: SP Incoming interface: Serial0, RPF nbr , ( , ( , ), ), 00:01:56/00:00:02, 00:01:56/00:00:01, 00:01:56/00:00:03, flags: flags: PT PT Incoming Incoming interface: interface: Serial1, Serial1, RPF RPF nbr nbr Outgoing Outgoing interface interface list: list: Not seeing any traffic, (S i,g) entry times out. 166

167 PIM ASM Pruning - IOS Source (SPT) Case To RP ( ) To Source S i A E1 B (*, ), 00:02:32/00:02:59, RP , flags: SP Incoming interface: Serial0, RPF nbr , Now (*,G) starts its timer. 167

168 PIM ASM Pruning - IOS Source (SPT) Case To RP ( ) To Source S i A E1 B (*, ), 00:03:33/00:00:02, 00:03:32/00:00:04, 00:03:32/00:00:03, 00:03:34/00:00:01, RP , flags: SP Incoming interface: Serial0, RPF nbr , After about 3 minutes

169 PIM ASM Pruning - IOS Source (SPT) Case To RP ( ) To Source S i A E1 B After about 3 minutes... the (*,G) entry times out. 169

170 PIM Bidir 170

171 Bidirectional (BiDir) PIM Idea: Use the same tree for traffic from sources towards RP and from RP to receivers Benefits: Less state in routers Only (*, G) state is used Source traffic follows the Shared Tree Flows up the Shared Tree to reach the RP Flows down the Shared Tree to reach all other receivers 171

172 PIM Modifications for BiDir Operation All trees rooted at the RP Data traveling from source toward RP is moving UPSTREAM Data traveling from RP toward receivers is moving DOWNSTREAM Designated Forwarders (DF) One DF per link Router with best path to the RP is elected DF BiDir (*,G) forwarding rules: DF is the only router that forwards packets traveling downstream onto the link DF is the only router that picks-up upstream traveling packets off the link to forward towards the RP 172

173 PIM Bidir Joining RP (DF) E E1 (DF) F E1 (DF) A B C E1 (DF) E1 (DF) E1 (DF) D E1 (DF) (*, ), 00:00:04/00:00:00, RP , flags: BC Bidir-Upstream: Ethernet0, RPF nbr Ethernet0, Bidir-Upstream/Sparse-Dense, 00:00:04/00:00:00 Ethernet1, Forward/Sparse-Dense, 00:00:04/00:02:55 IGMP Join Receiver 1 Receiver 1 Joins Group Causing Router D to Create (*, G) State 173

174 PIM Bidir Joining RP (DF) E E1 (DF) F E1 (DF) PIM (*,G) Join to DF A B C E1 (DF) E1 (DF) E1 (DF) D E1 (DF) (*, ), 00:00:49/00:02:41, RP , flags: B Bidir-Upstream: Ethernet0, RPF nbr Ethernet0, Bidir-Upstream/Sparse-Dense, 00:00:49/00:00:00 Ethernet1, Forward/Sparse-Dense, 00:00:49/00:02:41 Receiver 1 Router D Sends (*, G) Join to Router F (DF) Causing It to Create (*, G) State 174

175 PIM Bidir Joining RP (DF) PIM (*,G) Join to DF E E1 (DF) F E1 (DF) A B C E1 (DF) E1 (DF) E1 (DF) D E1 (DF) (*, ), 00:13:49/00:03:29, RP , flags: B Bidir-Upstream: Null, RPF nbr Ethernet0, Forward/Sparse-Dense, 00:13:49/00:02:35 Receiver 1 Router F Sends (*, G) Join to RP Causing It to Create (*, G) State 175

176 PIM Bidir Joining RP (DF) E E1 (DF) F E1 (DF) A B C E1 (DF) E1 (DF) E1 (DF) D E1 (DF) Receiver 1 Branch of Shared Tree Is Now Built Down to Receiver 1 176

177 PIM Bidir Joining RP (DF) E E1 (DF) F E1 (DF) A B C E1 (DF) E1 (DF) E1 (DF) D E1 (DF) IGMP Join Receiver 2 Receiver 1 Receiver 2 Also Joins Group 177

178 PIM Bidir Joining (*, ), 00:00:04/00:00:00, RP , flags: BC Bidir-Upstream: Ethernet0, RPF nbr RP (DF) Ethernet0, Bidir-Upstream/Sparse-Dense, 00:00:04/00:00:00 Ethernet1, Forward/Sparse-Dense, 00:00:04/00:02:55 E E1 (DF) F E1 (DF) A E1 (DF) B E1 (DF) C E1 (DF) D E1 (DF) Receiver 2 Receiver 1 Router B Creates (*, G) State 178

179 PIM Bidir Joining RP (DF) E E1 (DF) (*, ), 00:00:49/00:02:41, RP , flags: B Bidir-Upstream: Ethernet0, RPF nbr Outgoing Finterface list: PIM (*,G) Join to Ethernet0, DF E1 (DF) Bidir-Upstream/Sparse-Dense, 00:00:49/00:00:00 Ethernet1, Forward/Sparse-Dense, 00:00:49/00:02:41 A B C E1 (DF) E1 (DF) E1 (DF) D E1 (DF) Receiver 2 Receiver 1 Router B Sends (*, G) Join to E (DF) Causing It to Create (*, G) State 179

180 PIM Bidir Joining PIM (*,G) Join to DF RP (DF) E E1 (DF) (*, ), 00:13:49/00:03:29, RP , flags: B Bidir-Upstream: F Null, RPF nbr Outgoing E1 interface (DF) list: Ethernet0, Forward/Sparse-Dense, 00:13:49/00:02:35 A B C E1 (DF) E1 (DF) E1 (DF) D E1 (DF) Receiver 2 Receiver 1 Router E Sends (*, G) Join to RP (State on RP Remains Unchanged) 180

181 PIM Bidir Joining RP (DF) E E1 (DF) F E1 (DF) A E1 (DF) B E1 (DF) C E1 (DF) D E1 (DF) Receiver 2 Receiver 1 New Branch of Shared Tree Is Built to Receiver 2 181

182 PIM Bidir Sending RP (DF) E E1 (DF) F E1 (DF) A E1 (DF) B E1 (DF) C E1 (DF) D E1 (DF) Source Receiver 2 (*, ), 00:32:20/00:02:59, RP , flags: BP Bidir-Upstream: Ethernet0, RPF nbr Receiver 1 Ethernet0, Bidir-Upstream/Sparse-Dense, 00:32:20/00:00:00 Arriving Traffic from Source Causes Router A to Create (*, G) State 182

183 PIM Bidir Sending RP (DF) E E1 (DF) F E1 (DF) A E1 (DF) B E1 (DF) C E1 (DF) D E1 (DF) Source Receiver 2 Receiver 1 Traffic Is Forwarded Toward Router E and Also Arrives at IIF of Router B 183

184 PIM Bidir Sending E E1 (DF) RP (*, ), 00:00:04/00:00:00, RP , flags: BC (DF) Bidir-Upstream: Ethernet0, RPF nbr Ethernet0, Bidir-Upstream/Sparse-Dense, 00:00:04/00:00:00 Ethernet1, Forward/Sparse-Dense, 00:00:04/00:02:55 F E1 (DF) A E1 (DF) B E1 (DF) C E1 (DF) D E1 (DF) Source Receiver 2 Receiver 1 Router B Forwards Traffic Back Down Shared Tree ala Normal PIM-SM 184

185 PIM Bidir Sending RP (DF) E E1 (DF) F E1 (DF) A E1 (DF) B E1 (DF) C E1 (DF) D E1 (DF) Source Receiver 2 (*, ), 00:32:20/00:02:59, RP , flags: BP Bidir-Upstream: Ethernet0, RPF nbr Receiver 1 Ethernet0, Bidir-Upstream/Sparse-Dense, 00:32:20/00:00:00 Ethernet1, Forward/Sparse-Dense, 00:00:04/00:02:55 Router E Forwards Traffic on Toward RP 185

186 PIM Bidir Sending RP (DF) E E1 (DF) F E1 (DF) A E1 (DF) B E1 (DF) C E1 (DF) D E1 (DF) Source Receiver 2 Receiver 1 Traffic Forwarded Toward RP also flows down existing branch to Rcvr 1 186

187 PIM Bidir Sending RP (DF) E E1 (DF) F E1 (DF) A E1 (DF) B E1 (DF) C E1 (DF) D E1 (DF) Source Receiver 2 Receiver 1 Question: Does the RP even have to physically exist? 187

188 PIM Bidir RP RP (DF) E E1 (DF) F E1 (DF) A E1 (DF) B E1 (DF) C E1 (DF) D E1 (DF) Source Receiver 2 Receiver 1 Question: Does the RP even have to physically exist? Answer: No. It can just be a phantom address. 188

189 Recap: Common Multicast Flags - IOS S: s: B: F: P: J: T: Sparse Mode (in contrast to D for Dense Mode) SSM; only seen on (S,G) entries Bidir Register; set on First-Hop router Prune; entry has an empty OIL Join-SPT; (*,G) traffic exceeds SPT Threshold SPT; set on (S,G) entries after first (S,G) packet seen. Not applicable to SSM. L: Local; router should receive and process this traffic C: I: Connected; the router has a directly connected receiver. Router Received Source Specific Host Report (SSM) For Your Reference 189

190 For Your Reference New PIM Model 190

191 PIM Old Model IOS IPv4 For Your Reference (Simplified) show ip mroute show ip mroute count show ip igmp groups show ip msdp sa-cache STP IGMP PIM MSDP Route Processor L2 Forwarding Table Mroute Table SA Cache URIB L2 Forwarding IP FIB Various hardware dependent show commands. Hardware Drivers FIB TCAM ADJ Table MAC Table MET Other HW I/O Module 191

192 PIM New Model IOS-XR example For Your Reference show pim group-map show pim topology [sh ip mroute] show igmp groups show igmp snooping <xxx> show msdp sa-cache STP IGMP MSDP PIM Supervisor Engine PIM Topology show mrib route [sh ip mroute] MRIB URIB show mfib route show mfib connections show mfib counter [sh ip mroute] L2FIB MFIB Hardware Dependent show mfib hardware route olist loc <> show mfib hardware connection loc <> show mfib hardware ltrace loc <> show mfib hardware interface loc <> L2FIB MFIB PI MFIB PD Line Card show controller np counters all show controller np struct <id> all show controller np summary all NETIO NP PRM/uIDB MGID Server Fabric 192

193 PIM New Model NX-OS example For Your Reference show ip pim topology [sh ip mroute] show ip pim route [sh ip mroute] show ip igmp route show ip igmp snooping groups show ip msdp route STP IGMP MSDP PIM Supervisor Engine PIM Topology show routing ip multicast [sh ip mroute] MRIB URIB show forwarding distribution ip multicast route show forwarding distribution ip igmp snooping MFDM PIXM Hardware Dependent show forwarding ip multicast route IP FIB L2MCAST PIXMC Hardware Drivers show system internal forwarding ip multicast route show system internal ip igmp snooping FIB TCAM ADJ Table MAC Table MET Other HW I/O Module 193

194 PIM Topology Table Example XR For Your Reference RP/0/5/CPU0:rtr#sh pim topology Fri Sep 16 12:49: CEST IP PIM Multicast Topology Table Entry state: (*/S,G)[RPT/SPT] Protocol Uptime Info Entry flags: KAT - Keep Alive Timer, AA - Assume Alive, PA - Probe Alive RA - Really Alive, IA - Inherit Alive, LH - Last Hop DSS - Don't Signal Sources, RR - Register Received SR - Sending Registers, E - MSDP External, EX - Extranet DCC - Don't Check Connected, ME - MDT Encap, MD - MDT Decap MT - Crossed Data MDT threshold, MA - Data MDT group assigned Interface state: Name, Uptime, Fwd, Info Interface flags: LI - Local Interest, LD - Local Dissinterest, II - Internal Interest, ID - Internal Dissinterest, LH - Last Hop, AS - Assert, AB - Admin Boundary, EX Extranet (*, ) SM Up: 5w2d RP: * JP: Join(never) RPF: Decapstunnel1, Flags: GigabitEthernet0/0/0/0 5w2d fwd Join(00:03:20) ( , )RPT SM Up: 00:00:09 RP: * JP: Prune(never) RPF: Decapstunnel1, Flags: KAT(00:03:21) RA DCC RR (00:04:22) GigabitEthernet0/0/0/0 00:00:09 off Prune(00:03:20) ( , ) SM Up: 00:07:51 JP: Null(never) RPF: GigabitEthernet0/0/0/1, Flags: KAT(00:03:21) RA DCC RR (00:04:22) No interfaces in immediate olist 194

195 PIM Topology Table Entry Flags/Timers For Your Reference Entry Flags Flag/Timer Name Description KAT() Keep-Alive Timer Countdown timer. If goes to zero, entry is removed. Join() Join Timer Countdown timer. Time until a PIM Join is sent upstream. Prune() Prune Timer Countdown timer. Time until a PIM Prune is sent upstream. AA Assume Alive Only set after the route has been alive once. PA Probe Alive Check to see if any traffic is flowing for this route. RA Really Alive PIM sets this flag when it has been signaled that the route has seen traffic. IA Inherit Alive Inherit Alive Interfaces from Parent route LH Last Hop Last Hop Router. A directly connected host has joined via IGMP/MLD on one of the Entry's Interfaces. DSS Don't Signal Sources PIM doesn't want to be signaled when MFIB hears new sources on Shared Tree. RR Register Received PIM Register Messages are being Received SR Sending Registers PIM Register Messages are being Sent E MSDP External (S,G) learned from MSDP Peer DCC Don't Check Connected Don't check for directly connected Sources Interface Flags Flag/Timer Name Description Join() Join Timer Countdown timer. Time until Interface Join Times Out Prune() Prune Timer Countdown timer. Time until Interface Prune Times Out LI Local Interest Received IGMP/MLD report/join for group ("C" flag in IOS) LD Local Disinterest Received IGMP/MLD exclude (S,G) II Internal Interest Router CPU IGMP/MLD include join ("L" flag in IOS) ID Internal Disinterest Router CPU IGMP/MLD exclude (S,G) LH Last Hop Last Hop Router. A directly connected host has joined via IGMP/MLD on this Interface. AS Assert A PIM Assert has been seen on this Interface AB Admin Boundary Interface would be in olist but it is blocked by Admin Boundary. 195

196 PIM MRIB State Example XR For Your Reference RP/0/5/CPU0:rtr#show mrib route IP Multicast Routing Information Base Entry flags: L - Domain-Local Source, E - External Source to the Domain, C - Directly-Connected Check, S - Signal, IA - Inherit Accept, IF - Inherit From, D - Drop, MA - MDT Address, ME - MDT Encap, MD - MDT Decap, MT - MDT Threshold Crossed, MH - MDT interface handle CD - Conditional Decap, MPLS - MPLS Decap, MF - MPLS Encap, EX - Extranet Interface flags: F - Forward, A - Accept, IC - Internal Copy, NS - Negate Signal, DP - Don't Preserve, SP - Signal Present, II - Internal Interest, ID - Internal Disinterest, LI - Local Interest, LD - Local Disinterest, DI - Decapsulation Interface EI - Encapsulation Interface, MI - MDT Interface, LVIF - MPLS Encap, EX - Extranet (*, ) RPF nbr: Flags: C Up: 00:02:13 Outgoing Interface List GigabitEthernet0/2/1/0.102 Flags: F NS, Up: 00:02:13 ( , ) RPF nbr: Flags: Up: 00:00:07 Incoming Interface List GigabitEthernet0/2/1/1 Flags: A, Up: 00:00:07 Outgoing Interface List GigabitEthernet0/2/1/0.102 Flags: F NS, Up: 00:00:07 196

197 MRIB Entry Flags Entry Flags Flag/Timers Name Description UP Entry Up Timer Time Entry has existed C Directly-Connected Check Perform check on incoming packets applicable to this Entry. S Signal Signal PIM. IA Inherit Alive Inherit Alive Interfaces from Parent route IF Inherit From D Drop MA MDT Address MVPN MDT Tunnel Address (Multicast Address) ME MDT Encapsulate Encapsulate in MDT Tunnel MD MDT Decapsulate Decapsulate from MDT Tunnel MT Crossed Data MDT Threshold (S,G) traffic has crossed Data MDT Threshold. MH MDT interface handle Interface used for MVPN MDT Tunnel Interface Flags Flag/Timers Name Description UP Interface Up Timer Time Interface has existed in Outgoing Interface List F Forward Forward multicast packets on this interface A Accept Accept multicast packets on this interface IC Internal Copy NS Negate Signal Invert Signal status of Entry for this interface. (Often means "Signal".) DP Don't Preserve SP Signal Present MFIB is Signaling PIM. Typically for packet arriving on interface. II Internal Interest Router CPU IGMP/MLD include join ("L" flag in IOS) ID Internal Disinterest Router CPU IGMP/MLD exclude (S,G) LI Local Interest Received IGMP/MLD report/join for group ("C" flag in IOS) LD Local Disinterest Received IGMP/MLD exclude (S,G) DI Decapsulation Interface PIM Registers received on this interface. (Typically the DecapTunnel.) EI Encapsulation Interface PIM Registers sent on this interface. (Typically the EncapTunnel.) For Your Reference 197

198 More Information White Papers Web and Mailers Cisco Press RTFB = Read the Fine Book 198

199 Multicast Bedtime Stories 199