IP Multicast Survival Guide Part 2 - DFW Cisco User Group · 2016. 4. 6. · IP Multicast Survival Guide II -2. nd. Edition-rev6.pptx 3. To provide a “deep dive” into PIM ASM

IP Multicast Survival Guide II - 2nd Edition-rev6.pptx

IP Multicast Survival Guide Part 2

Second Edition

Beau WilliamsonCCIE 1356 R/S Emeritus

CiscoLive Distinguished Speakeraka “Multicast Survivorman”

Twitter: @Mr_Multicast

2IP Multicast Survival Guide II - 2nd Edition-rev6.pptx

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.


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.

1You still may be asked to perform unnatural network acts in your CCIE lab.

Survival Guide Goal


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


PIM ASM Review


PIM-SM Shared Tree Join

Receiver

RP

(*, G) JoinShared Tree

(*, G) State Created OnlyAlong the Shared Tree


PIM-SM Sender Registration

Receiver

RP

(S, G) Join

Source

(S, G) Register (unicast)Source Tree

(S, G) State Created OnlyAlong the Source TreeTraffic Flow

Shared Tree



Receiver

RPSource

Shared TreeSource Tree RP Sends a Register-Stop Back

to the First-Hop Router to Stop the Register Process(S, G) Register-Stop (unicast)

Traffic Flow

(S, G) Register (unicast)

(S, G) Traffic Begins Arriving at the RP via the Source Tree



Receiver

RPSource

Shared TreeSource Tree

Traffic FlowSource Traffic Flows NativelyAlong SPT to RPFrom RP, Traffic Flows Downthe Shared Tree to Receivers


PIM-SM SPT Switchover

Receiver

RP

(S, G) Join

Source

Source TreeShared Tree

Last-Hop Router Joins the Source TreeAdditional (S, G) State Is Created Along New Part of the Source Tree

Traffic Flow



Receiver

RPSource


(S, G)RP-bit Prune

Traffic Begins Flowing Down the New Branch of the Source TreeAdditional (S, G) State Is Created Along the Shared Tree to Prune Off (S, G) Traffic

Traffic Flow



Receiver

RPSource


(S, G) Traffic Flow Is Now Pruned Off of the Shared Tree and Is Flowing to the Receiver via the Source Tree

Traffic Flow



Receiver

RPSource


(S, G) Traffic Flow Is No Longer Needed by the RP so It Prunes the Flow of (S, G) Traffic

Traffic Flow

(S, G) Prune



Receiver

RPSource


(S, G) Traffic Flow Is Now Only Flowing to the Receiver via a Single Branch of the Source Tree

Traffic Flow


PIM Packets


PIM Packet Header

Ver:PIM Version = 2

Type:0 = Hello1 = Register (SM only)2 = Register-Stop (SM only)3 = Join/Prune4 = Bootstrap (SM BSR only)5 = Assert6 = Graft (DM only)7 = Graft-Ack (DM only)8 = C-RP-Announcement (SM BSR only)

PIMv2 is assigned protocol number 103317 153

• PIMv2 messages are multicast to the ALL-PIM-Routers (224.0.0.13) group with a TTL of 1.

Type Reserved ChecksumVer

For YourReference


PIM Hello Messages

Option Types:1 = Holdtime (Period of time in seconds before this PIM

neighbor times out.)19 = DR Priority20 = Generation ID

Type Reserved ChecksumVerOption LengthOption Type

Option Value

. . .

Option LengthOption TypeOption Value

317 153

For YourReference


PIM Join/Prune Packets

• 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

• Group List:List (by group) of sources to Join and/or Prune.

Type Reserved ChecksumVerUpstream Neighbor Address (Encoded-Unicast)

Num. Groups HoldtimeReserved

Group List

317 153

For YourReference


.

.

.

.

.

.

PIM Group Lists

Group Lists are used in Join/Prune and Graft/Graft-Ack messages.

Num. Prune SourcesNum. Join SourcesGroup-1 (Encoded-Group)

3115

Join Source-1 (Encoded-Source)

Join Source-n (Encoded-Source)Prune Source-1 (Encoded-Source)

Prune Source-n (Encoded-Source)

Num. Prune SourcesNum. Join SourcesGroup-2 (Encoded-Group)

• Group-xGroup IP address

• Num. Join Sources# of Joins for Group-x

• Num. Prune Sources# of Prunes for Group-x

• Join/Prune Source-yEncoded Source address to be Joined/Pruned.

For YourReference


PIM Assert Packets

• 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

Type Reserved ChecksumVerGroup Address (Encoded-Group)

317 153

Source Address (Encoded-Source)Metric Preference

MetricR

For YourReference


PIM Register Packets

• 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.

Type Reserved ChecksumVerReserved

317 153

Multicast Data Packet

B N

Sparse Mode Only

For YourReference


PIM Register-Stop Packets

• Group Address:The Group address from the Register message.

• Source Address:IP host address of Source from multicast data packet in Register message.

Type Reserved ChecksumVerGroup Address (Encoded-Group)

317 153

Source Address (Encoded-Source)

Sparse Mode Only

For YourReference


Encoded Unicast Addresses

Encoding Unicast Address . . .317 15

Addr Family. . . Unicast Address

• 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.

For YourReference


Source Address . . .

Encoded Source Addresses

Rsvd317 153

WREncodingAddr Family Mask LenS



• S = Sparse Mode bitIndicates Sparse Mode Group.

• W = Wildcard bitIndicates Join/Prune is a (*,G) Join/Prune.

• R = RP bitIndicates this Join/Prune should be sent up Shared Tree toward RP.

• Mask LenNumber of bits in the prefix of the Group Address.

• Source AddressAddress of Multicast Source

For YourReference


Encoded Group Addresses

Group Address . . .Reserved

317 153

EncodingAddr Family Mask Len



• Mask LenNumber of bits in the prefix of the Group Address.

• Group AddressMulticast Group Address

For YourReference


PIM Neighbor Discovery


171.68.37.2PIM Router 2

Highest IP Address Electedas “DR” (Designated Router)

PIM Hello

PIM Router 1171.68.37.1

PIM Hello

PIM Neighbor Discovery

PIMv2 Hellos are periodically multicast to the “All-PIM-Routers” (224.0.0.13) 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


PIM Neighbor Discovery - IOS

wan-gw8>show ip pim neighborPIM Neighbor TableNeighbor Interface Uptime/Expires Ver ModeAddress Prio/Mode171.68.0.70 FastEthernet0/0 2w1d/00:01:24 v2 1 / B S171.68.0.91 FastEthernet0/0 2w6d/00:01:01 v2 1 / B S171.68.0.82 FastEthernet0/0 7w0d/00:01:14 v2 5 / DR B S171.68.0.86 FastEthernet0/0 7w0d/00:01:13 v2 1 / B S171.68.0.80 FastEthernet0/0 7w0d/00:01:02 v2 1 / B S171.68.28.70 Serial2.31 22:47:11/00:01:16 v2 1 / B S171.68.28.50 Serial2.33 22:47:22/00:01:08 v2 1 / B S171.68.27.74 Serial2.36 22:47:07/00:01:21 v2 N /171.68.28.170 Serial0.70 1d4h/00:01:06 v2 N /171.68.27.2 Serial1.51 1w4d/00:01:25 v2 1 / B S171.68.28.110 Serial3.56 1d4h/00:01:20 v2 1 / B S171.68.28.58 Serial3.102 12:53:25/00:01:03 v2 1 / B S


DR Failover

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

A192.168.1.0/24.2 (DR) .1

Rtr-B>show ip pim neighborPIM Neighbor TableNeighbor Address Interface Uptime Expires Mode192.168.1.2 Ethernet0 4d22h 00:01:18 Sparse-Dense (DR)

B

00:01:18


PIM State & State Rules


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


PIM-SM State Example - IOS

sj-mbone> show ip mrouteFlags: 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 switchedTimers: Uptime/ExpiresInterface state: Interface, Next-Hop or VCD, State/Mode

(*, 224.1.1.1), 2w1d/00:00:00, RP 172.16.25.1, flags: SJCIncoming interface: Serial0/1, RPF nbr 172.16.4.1Outgoing interface list:Ethernet0/1, Forward/Sparse-Dense, 2w1d/00:01:40Serial0/0, Forward/Sparse-Dense, 00:4:52/00:02:08

(172.16.8.2, 224.1.1.1), 00:04:52/00:02:59, flags: CJTIncoming interface: Serial0/1, RPF nbr 172.16.4.1Outgoing interface list:Ethernet0/1, Forward/Sparse-Dense, 00:00:10/00:02:49Serial0/0, Forward/Sparse-Dense, 00:4:52/00:02:08


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


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)


(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


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


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


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



PIM-SM IOS State Flags S = Sparse C = Router has Directly Connected Host I = Router Received Source Specific Host Report (SSM) L = Local (Router is member) P = Pruned (All interfaces in OIL = Prune) T = Indicates at least one packet was forwarded via (S,G) entry

– Not applicable to SSM. “T” bit always set.


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)


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


PIM Source-Specific Multicast (SSM)


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)


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


PIM SSM Joining


PIM SSM Joining - IOS

E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

(172.16.8.2, 232.1.1.1), 00:00:09/00:02:51, flags: sPTIncoming interface: Ethernet0/2, RPF nbr 0.0.0.0Outgoing interface list: Null

A

B CRcvr1 Rcvr2

Source Data

Source Tree10.1.3.2

10.1.3.1

172.16.8.1



• Rcvr1 wishes to receive SSM S,G traffic. Sends IGMPv3 Join for S,G.1

IGMPv3 Join1

E0/2

E0/1

E0/1

Rcvr1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

A

B CRcvr2

Source Data

Source Tree10.1.3.2

10.1.3.1

172.16.8.1


(172.16.8.2, 232.1.1.1), 00:00:14/00:02:45, flags: sTIIncoming interface: Ethernet0/0, RPF nbr 10.1.2.1Outgoing interface list:

B Creates (172.16.8.2, 224.1.1.1) State


Ethernet0/1, Forward/Sparse, 00:00:14/00:02:45

E0/2

E0/1

E0/1

Rcvr1

A

C

Src172.16.8.2

E0/1E0/0

B

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr2

Source Data

Source Tree10.1.3.2

10.1.3.1

172.16.8.1



• B sends (S,G) Join towards Source.2

(S,G) Join 2

E0/0

E0/2

E0/1

E0/0E0/1

Rcvr1

10.1.2.2

10.1.2.1

A

C

Src172.16.8.2

E0/1E0/0

BRcvr2

Source Data

Source Tree10.1.3.2

10.1.3.1

172.16.8.1


(172.16.8.2, 232.1.1.1), 00:00:15/00:02:49, flags: sTIncoming interface: Ethernet0/2, RPF nbr 0.0.0.0Outgoing interface list: Null

A Updates (172.16.8.2, 224.1.1.1) State


E0/0

E0/2

E0/1

E0/0E0/1

Rcvr1

10.1.2.2

10.1.2.1

C

Src172.16.8.2

E0/1E0/0

A

B


Rcvr2

Source Data

Source Tree10.1.3.2

10.1.3.1

172.16.8.1


Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

CRcvr1

A

BRcvr2

Source Tree10.1.3.2

10.1.3.1

172.16.8.1


Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

CRcvr1

A

BRcvr2

Source Tree

IGMPv3 Join 3

• Rcvr2 wishes to receive SSM S,G traffic. Sends IGMPv3 Join for S,G.3

10.1.3.2

10.1.3.1

172.16.8.1


Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1

A

BRcvr2

Source Tree

(172.16.8.2, 232.1.1.1), 00:00:02/00:02:49, flags: sTIIncoming interface: Ethernet0/0, RPF nbr 10.1.3.1Outgoing interface list:

C Creates (172.16.8.2, 224.1.1.1) State

C

10.1.3.2

10.1.3.1


172.16.8.1


Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1

A

BRcvr2

Source Tree

C

10.1.3.2

10.1.3.1(S,G) Join4

172.16.8.1

• C sends (S,G) Join towards Source.4


(172.16.8.2, 232.1.1.1), 00:00:15/00:02:49, flags: sTIncoming interface: Ethernet0/2, RPF nbr 0.0.0.0Outgoing interface list:Ethernet0/0, Forward/Sparse, 00:28:03/00:02:43

A Updates (172.16.8.2, 224.1.1.1) StateEthernet0/1, Forward/Sparse, 00:00:03/00:02:48

Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

B C

A

172.16.8.1


Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

B

172.16.8.1

A

C


PIM SSM Pruning


(172.16.8.2, 232.1.1.1), 00:43:15/00:02:49, flags: sTIncoming interface: Ethernet0/2, RPF nbr 0.0.0.0Outgoing interface list:Ethernet0/0, Forward/Sparse, 00:43:15/00:02:44Ethernet0/1, Forward/Sparse, 00:40:03/00:02:55

Source Data

PIM SSM Pruning - IOS

E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

B

172.16.8.1

A

C

State in A Before Pruning


(172.16.8.2, 232.1.1.1), 00:43:15/00:02:49, flags: sTIIncoming interface: Ethernet0/0, RPF nbr 10.1.2.1Outgoing interface list:Ethernet0/1, Forward/Sparse, 00:43:15/00:02:44

Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

B

172.16.8.1

A

C

State in B Before Pruning



Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

B

172.16.8.1

A

C

State in C Before Pruning


Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

B

172.16.8.1

A

C

• B is a Leaf router. Last Rcvr, leaves (S,G). 1

IGMP Leave1



Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

B

172.16.8.1

A

C

• B removes E0/1 from (S,G) “oilist”.2

2

sTP



Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

B

172.16.8.1

A

C

(S,G) Prune 3

• B’s (S,G) “oilist” now empty; triggers (S,G) Prune toward source.3

sTP


(172.16.8.2, 232.1.1.1), 00:00:15/00:02:49, flags: sTIncoming interface: Ethernet0/2, RPF nbr 0.0.0.0Outgoing interface list:Ethernet0/0, Forward/Sparse, 00:28:03/00:02:43Ethernet0/1, Forward/Sparse, 00:00:03/00:02:48

Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

B

172.16.8.1

A

C


• A removes E0/0 from (S,G) “oilist”.4

4


Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

B

172.16.8.1

A

C

• C is a Leaf router. Last Rcvr, leaves (S,G). 5

IGMP Leave 5



Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

B

172.16.8.1

A

C

sTP

• C removes E0/1 from (S,G) “oilist”.6

6


Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

B

172.16.8.1

A

C

(S,G) Prune7

• C’s (S,G) “oilist” now empty; triggers (S,G) Prune toward source.7



Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

B

172.16.8.1

A

C

sTP

• A removes E0/1 from (S,G) “oilist”.8

8


(172.16.8.2, 232.1.1.1), 00:43:48/00:00:04, flags: sTPIncoming interface: Ethernet0/0, RPF nbr 10.1.2.1Outgoing interface list:

Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

172.16.8.1

A

C

After about 3 minutes . . .

B






Source Data


E0/2

E0/1

E0/1

Src172.16.8.2

E0/1E0/0

E0/0

E0/010.1.2.2

10.1.2.1

Rcvr1 Rcvr2

Source Tree10.1.3.2

10.1.3.1

172.16.8.1

A

C

(S, G) State times out


B

After about 3 minutes . . .Same for routers C and A


PIM Any-Source Multicast (ASM)


PIM ASM Joining


Shared Tree

PIM ASM Joining - IOS

• Rcvr wishes to receive group G traffic. Sends IGMP Join for G.1

IGMP Join1

E0S0

S1

E0E1

Rcvr

To RP (10.1.5.1)

10.1.2.2

10.1.2.110.1.4.2

A

B


(*, 224.1.1.1), 00:00:05/00:00:00, RP 10.1.5.1, flags: SCIncoming interface: Ethernet0, RPF nbr 10.1.2.1Outgoing interface list:

E0S0

S1

E0E1

Rcvr

To RP (10.1.5.1)

10.1.2.2

10.1.2.110.1.4.2

B Creates (*, 224.1.1.1) State


Ethernet1, Forward/Sparse-Dense, 00:00:05/00:02:54

Shared Tree

A

B


E0S0

S1

E0E1

Rcvr

To RP (10.1.5.1)

10.1.2.2

10.1.2.110.1.4.2



• B sends (*,G) Join towards RP.2

(*,G) Join2

Shared Tree

A

B


(*, 224.1.1.1), 00:00:05/00:00:00, RP 10.1.5.1, flags: SIncoming interface: Serial0, RPF nbr 10.1.4.1Outgoing interface list:

E0S0

S1

E0E1

Rcvr

To RP (10.1.5.1)

10.1.2.2

10.1.2.110.1.4.2

A Creates (*, 224.1.1.1) State



Shared Tree

A

B


E0S0

S1

E0E1

Rcvr

To RP (10.1.5.1)

10.1.2.2

10.1.2.110.1.4.2


• A sends (*,G) Join towards RP.3


• B sends (*,G) Join towards RP.2

(*,G) Join3

• Shared tree is built all the way back to the RP.4

Shared Tree4

Shared Tree

A

B


PIM ASM Registering


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


PIM ASM Registering –Receiver Joins First


State in “RP” Before Any Source Registers(With Receivers on Shared Tree)

RP

Shared Tree

S3S0 S1

PIM ASM Registering - IOSReceiver Joins Group First

E0 S1S0S0A B

(*, 224.1.1.1), 00:03:14/00:00:00, RP 171.68.28.140, flags:SIncoming interface: Null, RPF nbr 0.0.0.0,Outgoing interface list:Serial0, Forward/Sparse-Dense, 00:03:14/00:03:15Serial1, Forward/Sparse-Dense, 00:03:14/00:03:15

C


State in B Before Any Source Registers(With Receivers on Shared Tree)


rtr-b>sh ip mroute 224.1.1.1

No such group

RP

Shared Tree

S0 S1A B CS3E0 S1S0S0


State in A Before Any Source Registers(With Receivers on Shared Tree)


rtr-a>sh ip mroute 224.1.1.1

No such group.

RP

Shared Tree



(171.68.37.121, 224.1.1.1)Mcast Packets

Source171.68.37.121


• Source begins sending group G traffic. 1

1 RP

Shared Tree



(*, 224.1.1.1), 00:00:03/00:00:00, RP 171.68.28.140, flags: SPIncoming interface: Serial0, RPF nbr 171.68.28.191,Outgoing interface list: Null

(171.68.37.121, 224.1.1.1), 00:00:03/00:02:56, flags: FPTIncoming interface: Ethernet0, RPF nbr 0.0.0.0, Outgoing interface list: Null

A Creates (S, G) State for Source(After Automatically Creating a (*, G) entry)


Registering


• A encapsulates packets in Registers; unicasts to RP.2

Register Msgs2(171.68.37.121, 224.1.1.1)Mcast Packets

Source171.68.37.121

RP

Shared Tree


FPT


“RP” Processes Register; Creates (S, G) State


• RP (C) de-encapsulates packets; forwards down Shared tree.3

(*, 224.1.1.1)Mcast Traffic

3

(*, 224.1.1.1), 00:09:21/00:00:00, RP 171.68.28.140, flags: SIncoming interface: Null, RPF nbr 0.0.0.0,Outgoing interface list:Serial0, Forward/Sparse-Dense, 00:09:21/00:02:38Serial1, Forward/Sparse-Dense, 00:03:14/00:02:46

(171.68.37.121, 224.1.1.1, 00:01:15/00:02:46, flags:Incoming interface: Serial3, RPF nbr 171.68.28.139,Outgoing interface list:Serial0, Forward/Sparse-Dense, 00:00:49/00:02:11Serial1, Forward/Sparse-Dense, 00:00:49/00:02:11

Register Msgs(171.68.37.121, 224.1.1.1)Mcast Packets

Source171.68.37.121

RP

Shared Tree


171.68.28.139


171.68.28.139

PIM ASM RegisteringReceiver Joins Group First

• RP sends (S,G) Join toward Source to build SPT.4

(S,G) Join 4


Source171.68.37.121

RP

Shared Tree




B Processes Join, Creates (S, G) State(After Automatically Creating the (*, G) Entry)


• B sends (S,G) Join toward Source to continue building SPT.5

(S,G) Join 5


(171.68.37.121, 224.1.1.1), 00:04:28/00:01:32, flags: Incoming interface: Serial0, RPF nbr 171.68.28.190Outgoing interface list:


Source171.68.37.121

RP

Shared Tree



Serial1, Forward/Sparse-Dense, 00:04:28/00:01:32

171.68.28.190


A Processes the (S, G) Join; Adds Serial0 to OIL



(171.68.37.121, 224.1.1.1), 00:04:28/00:01:32, flags: FTIncoming interface: Ethernet0, RPF nbr 0.0.0.0, RegisteringOutgoing interface list:


Source171.68.37.121

RP

Shared Tree





PIM ASM RegisteringReceiver Joins Group First

• RP begins receiving (S,G) traffic down SPT. 6

6


Source171.68.37.121

RP

Shared Tree





(171.68.37.121, 224.1.1.1, 00:01:15/00:02:46, flags:TIncoming interface: Serial3, RPF nbr 171.68.28.139,Outgoing interface list:Serial0, Forward/Sparse-Dense, 00:00:49/00:02:11Serial1, Forward/Sparse-Dense, 00:00:49/00:02:11

Traffic Arriving via SPT Is Forwarded Down Shared Tree(This Causes the “T” Flag to Be Set)


T


Source171.68.37.121

RP

Shared Tree


Note “T”FlagIs Now Set



Register-Stop


• Once “T” Flag is set, next “Register” causes RP to send back a “Register-Stop” to A

7


Source171.68.37.121

RP

Shared Tree





(171.68.37.121, 224.1.1.1), 00:04:28/00:01:32, flags: FTIncoming interface: Ethernet0, RPF nbr 0.0.0.0, RegisteringOutgoing interface list:Serial0, Forward/Sparse-Dense, 00:04:28/00:01:32


A Stops Sending Register Messages(Final State in A)

• (S,G) Traffic now flowing down a single path (SPT) to RP.8

8

Register-Stop


RP

Shared Tree



Source171.68.37.121


Final State in B



(171.68.37.121, 224.1.1.1), 00:04:28/00:01:32, flags: T Incoming interface: Serial0, RPF nbr 171.68.28.190Outgoing interface list:Serial1, Forward/Sparse-Dense, 00:04:28/00:01:32

(171.68.37.121, 224.1.1.1)Mcast Packets

Source171.68.37.121

RP

Shared Tree




Final State in the “RP”(With Receivers on Shared Tree)



(171.68.37.121, 224.1.1.1, 00:01:15/00:02:46, flags: TIncoming interface: Serial3, RPF nbr 171.68.28.139,Outgoing interface list:Serial0, Forward/Sparse-Dense, 00:00:49/00:02:11Serial1, Forward/Sparse-Dense, 00:00:49/00:02:11

(171.68.37.121, 224.1.1.1)Mcast Packets

Source171.68.37.121

RP

Shared Tree




PIM ASM Registering –Source Registers First


rtr-c>show ip mroute 224.1.1.1

Group 224.1.1.1 not found.

State in “RP” before Registering(Without Receivers on Shared Tree)

PIM ASM Registering - IOSSource Registers First

RP

S3S0

S1S0S0E0S1

A B C


rtr-b>show ip mroute 224.1.1.1


State in B Before Any Source Registers(With Receivers on Shared Tree)

RP

S3S0

S1S0S0E0S1

A B C



rtr-a>show ip mroute 224.1.1.1


State in A Before Any Source Registers(With Receivers on Shared Tree)

RP

S3S0

S1S0S0E0S1

A B C



(171.68.37.121, 224.1.1.1)Mcast Packets

RP

Source171.68.37.121


S3S0

S1S0S0E0S1

1

A B C




(171.68.37.121, 224.1.1.1), 00:00:03/00:02:56, flags: FPTIncoming interface: Ethernet0, RPF nbr 0.0.0.0,Outgoing interface list: Null

A Creates (S, G) State for Source(After Automatically Creating a (*, G) Entry)



• A encapsulates packets in Registers; unicasts to RP.2

Register Msgs2(171.68.37.121, 224.1.1.1)Mcast Packets

RP

Source171.68.37.121

S3S0

S1S0S0E0S1

A B C

Registering


(*, 224.1.1.1), 00:01:15/00:00:00, RP 171.68.28.140, flags: SPIncoming interface: Null, RPF nbr 0.0.0.0,Outgoing interface list: Null

(171.68.37.121, 224.1.1.1), 00:01:15/00:01:45, flags: PIncoming interface: Serial3, RPF nbr 171.68.28.139,Outgoing interface list: Null

“RP” Processes Register; Creates (S, G) State(After Automatically Creating the (*, G) Entry)


• RP (C) has no receivers on Shared Tree; discards packet.3

3


RP

S3S0

S1S0S0E0S1

A B CSource171.68.37.121



• RP sends “Register-Stop” to A.4

Register-Stop4


RP

S3S0

S1S0S0E0S1

A B CSource171.68.37.121



• A stops encapsulating traffic in Register Messages;drops packets from Source.

5

5

(171.68.37.121, 224.1.1.1)Mcast Packets

RP

S3S0

S1S0S0E0S1

A B CSource171.68.37.121



(171.68.37.121, 224.1.1.1), 00:01:28/00:01:32, flags: FPTIncoming interface: Ethernet0, RPF nbr 0.0.0.0Outgoing interface list: Null

State in A After Registering(Without Receivers on Shared Tree)


(171.68.37.121, 224.1.1.1)Mcast Packets

RP

S3S0

S1S0S0E0S1

A B CSource171.68.37.121


State in B after A Registers(Without Receivers on Shared Tree)


rtr-b>show ip mroute 224.1.1.1


(171.68.37.121, 224.1.1.1)Mcast Packets

RP

S3S0

S1S0S0E0S1

A B CSource171.68.37.121


(*, 224.1.1.1), 00:01:15/00:00:00, RP 171.68.28.140, flags: SPIncoming interface: Null, RPF nbr 0.0.0.0,Outgoing interface list: Null

(171.68.37.121, 224.1.1.1), 00:01:15/00:01:45, flags: PIncoming interface: Serial3, RPF nbr 171.68.28.139,Outgoing interface list: Null

State in RP After A Registers(Without Receivers on Shared Tree)

171.68.28.139


(171.68.37.121, 224.1.1.1)Mcast Packets

RP

S3S0

S1S0S0E0S1

A B CSource171.68.37.121



• RP (C) receives (*, G) Join from a receiver on Shared Tree. 6

(*, G) Join6

(171.68.37.121, 224.1.1.1)Mcast Packets

RP

S3S0

S1S0S0E0S1

A B CSource171.68.37.121


(*, 224.1.1.1), 00:09:21/00:00:00, RP 171.68.28.140, flags: SIncoming interface: Null, RPF nbr 0.0.0.0,Outgoing interface list:

(171.68.37.121, 224.1.1.1, 00:01:15/00:02:46, flags: TIncoming interface: Serial3, RPF nbr 171.68.28.139,Outgoing interface list:

RP Processes (*,G) Join(Adds Serial1 to Outgoing Interface Lists)




• RP sends (S,G) Joins for all known Sources in Group.7

7(S, G) Join

(171.68.37.121, 224.1.1.1)Mcast Packets

RP

S3S0

S1S0S0E0S1

A B CSource171.68.37.121





B Processes Join, Creates (S, G) State(After Automatically Creating the (*, G) Entry)

171.68.28.190


• B sends (S,G) Join toward Source to continue building SPT.8

(S, G) Join8

(171.68.37.121, 224.1.1.1)Mcast Packets

RP

S3S0

S1S0S0E0S1

A B CSource171.68.37.121



(171.68.37.121, 224.1.1.1), 00:04:28/00:01:32, flags: FTIncoming interface: Ethernet0, RPF nbr 0.0.0.0, Outgoing interface list:

A Processes the (S, G) Join; Adds Serial0 to OIL



• RP begins receiving (S,G) traffic down SPT.9

9

• RP forwards (S,G) traffic down Shared Tree to receivers.10


10

(171.68.37.121, 224.1.1.1)Mcast Packets

RP

S3S0

S1S0S0E0S1

A B CSource171.68.37.121





Final state in Router A


(171.68.37.121, 224.1.1.1)Mcast Packets

RP

S3S0

S1S0S0E0S1

A B CSource171.68.37.121




(171.68.37.121, 224.1.1.1), 00:04:28/00:01:32, flags: TIncoming interface: Serial0, RPF nbr 171.68.28.190Outgoing interface list:


Final State in B After Receivers Join

171.68.28.190


(171.68.37.121, 224.1.1.1)Mcast Packets

RP

S3S0

S1S0S0E0S1

A B CSource171.68.37.121







Final State in RP After Receivers Join


(171.68.37.121, 224.1.1.1)Mcast Packets

RP

S3S0

S1S0S0E0S1

A B CSource171.68.37.121

171.68.28.139



PIM ASM Registering –Receiver Along the SPT





Current state in Router A

PIM ASM Registering - IOSReceivers Along the SPT

RP

Source171.68.37.121

(171.68.37.121, 224.1.1.1)Mcast Packets


S0 S1 S3

S1A B

Shared Tree

CS0E0





Current State in B

RP

Source171.68.37.121

(171.68.37.121, 224.1.1.1)Mcast Packets



S1A B

Shared Tree

CS0 S1 S3S0E0






Current State in the RP


RP

Source171.68.37.121

(171.68.37.121, 224.1.1.1)Mcast Packets


S1A B

Shared Tree

CS0 S1 S3S0E0




RP

Source171.68.37.121

(171.68.37.121, 224.1.1.1)Mcast Packets


S1A

E0

Rcvr

B

IGMP Join1

Shared Tree

CS0 S1 S3S0E0


(*, 224.1.1.1), 00:04:28/00:00:00, RP 171.68.28.140, flags: SCIncoming interface: Serial1, RPF nbr 171.68.28.140,Outgoing interface list:

(171.68.37.121, 224.1.1.1), 00:04:28/00:01:32, flags: CTIncoming interface: Serial0, RPF nbr 171.68.28.190Outgoing interface list:


B adds Ethernet0 to (*,G) and (S,G) OIL’s




RP

Source171.68.37.121

(171.68.37.121, 224.1.1.1)Mcast Packets


S1A

E0

Rcvr

B

Shared Tree

C

• Traffic begins flowing to Rcvr via (S,G)2

S0 S1 S3S0E0

2


E0

Rcvr


• B triggers a (*,G) Join to join the Shared Tree3

(*, G) Join2

RP

Source171.68.37.121

(171.68.37.121, 224.1.1.1)Mcast Packets


S1A

Shared Tree

CS0 S1 S3S0E0 B






RP adds Serial3 to (*,G) OIL



E0

Rcvr

RP

Source171.68.37.121

(171.68.37.121, 224.1.1.1)Mcast Packets


S1A B C

Shared Tree

S0 S1 S3S0E0

Pop Quiz:Why didn’t it copy Serial3 to theOIL of the (S,G) entry?



• Other Group G traffic can now flow to Rcvr via Shared Tree.(Note: 171.68.37.121 traffic doesn’t flow to RP then back down to B)

4

E0

Rcvr

RP

Source171.68.37.121

(171.68.37.121, 224.1.1.1)Mcast Packets


S1A B C

Shared Tree

S0 S1 S3S0E0


PIM ASM – SPT Switchover


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


(*, 224.1.1.1), 00:01:43/00:02:13, RP 10.1.5.1, flags: SIncoming interface: Serial0, RPF nbr 10.1.5.1,Outgoing interface list:

Serial1, Forward/Sparse-Dense, 00:01:43/00:02:11Serial2, Forward/Sparse-Dense, 00:00:32/00:02:28

State in C Before Switch

E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2

S110.1.4.1 To Source “Si”

To RP (10.1.5.1)S0

E0

Rcvr B

S2

S0

PIM ASM SPT-Switchover - IOS

A

B

C

D

Shared Tree


(*, 224.1.1.1), 00:01:43/00:02:13, RP 10.1.5.1, flags: SCIncoming interface: Serial0, RPF nbr 10.1.4.9,Outgoing interface list:


State in D Before Switch


E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

Rcvr B

S2

S0

A

B

Shared Tree

C

D




State in A Before Switch


E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

Rcvr B

S2

S0

A

B

Shared Tree

C

D


(*, 224.1.1.1), 00:01:43/00:02:13, RP 10.1.5.1, flags: SCJIncoming interface: Ethernet0, RPF nbr 10.1.2.1,Outgoing interface list:


State in B Before Switch


Note “J”Flag is set

J

E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

Rcvr B

S2

S0

A

B

C

Shared Tree

D





• New source (Si,G) packet arrives down Shared tree.1

E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

Rcvr B

S2

S0

A

B

C

D1

(Si, G) Traffic FlowShared Tree Flow






(171.68.37.121, 224.1.1.1), 00:00:28/00:02:51, flags: CJ Incoming interface: Ethernet0, RPF nbr 10.1.2.1Outgoing interface list:



• Because of “C” bit, B creates (Si,G) state to cut over to SPT.2

2

E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

Rcvr B

S2

S0

A

B

C

D (Si, G) Traffic FlowShared Tree Flow



• B sends (Si,G) Join towards Si .3

(Si,G) Join3

E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

Rcvr B

S2

S0

A

B

C







A creates (Si,G) state


E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

Rcvr B

S2

S0

A

B

C




• A triggers (Si,G) Join toward Si.4

(Si,G) Join4

E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

Rcvr B

S2

S0

A

B

C

D

SPT Tree Flow




• (Si, G) traffic begins flowing down SPT tree instead of Shared Tree.5

E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

Rcvr B

S2

S0

C

D

• A triggers (Si,G) Join toward Si.4

A

B SPT Tree Flow








“T”Flag Set by Arriving Traffic on SPT

T

E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

S2

S0

C

D

A

B

Rcvr B

SPT Tree Flow








• Once T Flag is set, A triggers (Si,G)RP-bit Prunes toward RP.6

(Si,G)RP-bit Prune6

E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

S2

S0

C

D

A

B

Note RPF Info Does Not Match. This Indicates SPT and RPT Diverge.

Rcvr B

SPT Tree Flow





C creates (Si, G) RP-bit State and removes Serial1 from (Si, G)


E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

S2

S0

C

DB

A

Note: Because “R” bit is set, Incoming interface points to RP not Source.

(171.68.37.121, 224.1.1.1), 00:13:28/00:02:53, flags: R Incoming interface: Serial0, RPF nbr 10.1.5.1Outgoing interface list:


Rcvr B

SPT Tree Flow




• Unnecessary (Si, G) traffic is pruned from the Shared tree.7

7E0

S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

S2

S0

C

D

A

B

Rcvr B

SPT Tree Flow



(*, 224.1.1.1), 00:01:43/00:00:00, RP 10.1.5.1, flags: SCJIncoming interface: Serial0, RPF nbr 10.1.4.9,Outgoing interface list:



E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

S2

S0

C

D

A

B

Rcvr B

• Because of “C” bit, D also creates (Si,G) state to cut over to SPT.8

(171.68.37.121, 224.1.1.1), 00:00:28/00:02:51, flags: CJ Incoming interface: Serial0, RPF nbr 10.1.3.1Outgoing interface list:


SPT Tree Flow




E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

S2

S0

C

D

A

B

Rcvr B

• D triggers (Si,G) Join toward Si.9

(Si,G) Join9

SPT Tree Flow





(171.68.37.121, 224.1.1.1), 00:13:28/00:02:53, flags: R Incoming interface: Serial0, RPF nbr 10.1.5.1Outgoing interface list:


C resets (Si, G) RP-bit State


E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

S2

S0

C

DB

A

Rcvr B

Serial1, RPF nbr 10.1.4.2

and RPF’s (Si, G) toward Source.

SPT Tree Flow




E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

S2

S0

C

DB

A

Rcvr B

• C triggers (Si,G) Join toward Si.10

(Si,G) Join10

SPT Tree Flow








E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

S2

S0

C

DB

A

Rcvr B

A adds Serial0 to (Si,G) OILSerial0, Forward/Sparse-Dense, 00:13:25/00:02:30

SPT Tree Flow




E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

S2

S0

C

B

A

Rcvr B

Traffic flows to Rcvr B via SPT.

D

SPT Tree Flow





(171.68.37.121, 224.1.1.1), 00:13:28/00:02:53, flags:TIncoming interface: Serial1, RPF nbr 10.1.4.2Outgoing interface list:



E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

S2

S0

C

B

A

Rcvr B

D

Note RPF Info Does Not Match. This Indicates SPT and RPT Diverge.

• Once T Flag is set, C triggers (Si,G)RP-bit Prunes toward RP.11

(Si,G)RP-bit Prune

11

SPT Tree Flow




E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

S2

S0

C

B

A

Rcvr B

D

All (Si,G) Traffic pruned from Shared Tree.

SPT Tree Flow




E0S0

S1

E0E1

Rcvr A

10.1.2.2

10.1.2.110.1.4.2


To RP (10.1.5.1)S0

E0

S2

S0

C

B

A

Rcvr B

But what does the Shared Tree look like now?

Shared Tree

D

Don’t confuse Forwarding State with Tree Topology!

SPT Tree Flow



PIM ASM Pruning


(*, 224.1.1.1), 00:01:43/00:02:13, RP 10.1.5.1, flags: SCIncoming interface: Ethernet0, RPF nbr 10.1.2.1,Outgoing interface list:



S1

E1

Rcvr A

To RP (10.1.5.1)

(Si, G) Traffic FlowShared TreeSPT Tree

PIM ASM Pruning - IOS Shared Tree Case

A

B

S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0






S1

E1

Rcvr A

To RP (10.1.5.1)


A

B

S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0



• B is a Leaf router. Last Rcvr, leaves group G. 1

IGMP Leave1

S1

E1

Rcvr A

To RP (10.1.5.1)


A

B

S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0


(*, 224.1.1.1), 00:01:43/00:02:13, RP 10.1.5.1, flags: SIncoming interface: Ethernet0, RPF nbr 10.1.2.1,Outgoing interface list:



• B removes Ethernet1 from (*,G) and any (Si,G) “oilists”.2

2

S1

E1

To RP (10.1.5.1)


A

B

P

S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0


(*, 224.1.1.1), 00:01:43/00:02:13, RP 10.1.5.1, flags: SIncoming interface: Ethernet0, RPF nbr 10.1.2.1,Outgoing interface list:


• B removes Ethernet1 from (*,G) and any (Si,G) “oilists”.2

• B’s (*,G) “oilist” now empty; triggers (*,G) Prune toward RP.3

(*,G) Prune3

S1

E1

To RP (10.1.5.1)


A

B

P

S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0


(*, 224.1.1.1), 00:01:43/00:02:13, RP 10.1.5.1, flags: S Incoming interface: Serial0, RPF nbr 10.1.4.1,Outgoing interface list:



S1

E1

To RP (10.1.5.1)


A

B

P

• A receives Prune; removes E0 from (*,G) “oilist”.(After the 3 second Multi-access Network Prune delay.)

4

S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0


(*, 224.1.1.1), 00:01:43/00:02:13, RP 10.1.5.1, flags: SP Incoming interface: Serial0, RPF nbr 10.1.4.1,Outgoing interface list:


S1

E1

To RP (10.1.5.1)


A

B

• A receives Prune; removes E0 from (*,G) “oilist”.(After the 3 second Multi-access Network Prune delay.)

4

• A’s (*,G) “oilist” now empty; triggers (*,G) Prune toward RP.5

(*,G) Prune5

S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0



• Pruning continues back toward RP.6

6

S1

E1

To RP (10.1.5.1)


A

B

S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0







PIM ASM Pruning - IOSSource (SPT) Case

S1

E1

Rcvr

To RP (10.1.5.1)To Source “Si”

B

Shared Tree

(Si, G) Traffic FlowSPT Tree

AS0

E0 10.1.2.2

10.1.2.110.1.4.2

E0




(171.68.37.121, 224.1.1.1), 00:01:05/00:01:55, flags: CJT Incoming interface: Ethernet0, RPF nbr 10.1.2.1Outgoing interface list:




S1

E1

Rcvr



A

B

Shared Tree

S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0


(*, 224.1.1.1), 00:01:43/00:00:00, RP 10.1.5.1, flags: SC Incoming interface: Ethernet0, RPF nbr 10.1.2.1,Outgoing interface list:





• B is a Leaf router. Last Rcvr leaves group G. 1

IGMP Leave1

S1

E1

Rcvr


A

B

Shared Tree


S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0







S1

E1


A

B

Shared Tree


• B removes Ethernet1 from (*,G) and all (S,G) OIL’s.2

2

S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0

P


(*, 224.1.1.1), 00:01:43/00:00:00, RP 10.1.5.1, flags: SCPIncoming interface: Ethernet0, RPF nbr 10.1.2.1,Outgoing interface list:

(171.68.37.121, 224.1.1.1), 00:01:05/00:01:55, flags: CJPT Incoming interface: Ethernet0, RPF nbr 10.1.2.1Outgoing interface list:


• B’s (*,G) OIL now empty; triggers (*,G) Prune toward RP.3

(*,G) Prune 3

S1

E1


B

AShared Tree


S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0


(*, 224.1.1.1), 00:01:43/00:00:00, RP 10.1.5.1, flags: SCPIncoming interface: Ethernet0, RPF nbr 10.1.2.1,Outgoing interface list:

(171.68.37.121, 224.1.1.1), 00:01:05/00:01:55, flags: CJPT Incoming interface: Ethernet0, RPF nbr 10.1.2.1Outgoing interface list:


• B’s (S,G) OIL also now empty; triggers (S, G) Prune towards Si .4

(S,G) Prune 4

S1

E1


B

AShared Tree


S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0


(*, 224.1.1.1), 00:01:43/00:00:00, RP 10.1.5.1, flags: S Incoming interface: Serial0, RPF nbr 10.1.4.1,Outgoing interface list:


(171.68.37.121, 224.1.1.1), 00:01:05/00:01:55, flags: T Incoming interface: Serial1, RPF nbr 10.1.9.2Outgoing interface list:



• After A receives (*, G) Prune; removes E0 from (*,G) & (S,G) OIL’s(After the 3 second Multi-access Network Prune delay.)

5

5

S1

E1


B

AShared Tree


S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0

P

(171.68.37.121, 224.1.1.1), 00:01:05/00:01:55 flags: PT


(*, 224.1.1.1), 00:02:32/00:00:00, RP 10.1.5.1, flags: SPIncoming interface: Serial0, RPF nbr 10.1.4.1,Outgoing interface list:

(171.68.37.121, 224.1.1.1), 00:01:56/00:00:53, flags: PTIncoming interface: Serial1, RPF nbr 10.1.9.2Outgoing interface list:


• A’s (*,G) OIL now empty; triggers (*,G) Prune toward RP.6

(*,G) Prune6

S1

E1


A

B

Shared Tree


S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0





• A’s (S,G) OIL also now empty; triggers (S,G) Prune towards Si .7

(Si ,G) Prune7

S1

E1


A

B


S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0





S1

E1


A

B

• (Si,G) traffic ceases flowing down SPT.8

8

S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0





S1

E1


A

B

Not seeing any traffic, (Si,G) entry times out.



S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0




S1

E1


A

B

Now (*,G) starts its timer.

S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0




S1

E1


A

B

After about 3 minutes . . .




S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0



S1

E1


A

B

S0

E0 10.1.2.2

10.1.2.110.1.4.2

E0

After about 3 minutes . . . the (*,G) entry times out.


PIM Bidir


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


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


(*, 224.1.1.1), 00:00:04/00:00:00, RP 172.16.21.1, flags: BCBidir-Upstream: Ethernet0, RPF nbr 172.16.9.1Outgoing interface list:

Ethernet0, Bidir-Upstream/Sparse-Dense, 00:00:04/00:00:00Ethernet1, Forward/Sparse-Dense, 00:00:04/00:02:55

PIM Bidir Joining

RP

E F

A B CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

IGMP Join

D

Receiver 1 Joins Group Causing Router “D” to Create (*, G) State


PIM Bidir Joining

PIM (*,G) Join to DF

Router “D” Sends (*, G) Join to Router “F” (DF) Causing It to Create (*, G) State

RP

E

A B CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

D

(*, 224.1.1.1), 00:00:49/00:02:41, RP 172.16.21.1, flags: BBidir-Upstream: Ethernet0, RPF nbr 172.16.1.1Outgoing interface list:


F


PIM Bidir Joining


Router “F” Sends (*, G) Join to “RP” Causing It to Create (*, G) State

E F

A B CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

D

(*, 224.1.1.1), 00:13:49/00:03:29, RP 172.16.21.1, flags: BBidir-Upstream: Null, RPF nbr 0.0.0.0Outgoing interface list:


RP


PIM Bidir Joining

Branch of Shared Tree Is Now Built Down to Receiver 1

E

A B CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

RP

F

D


PIM Bidir Joining

Receiver 2

IGMP Join

Receiver 2 Also Joins Group

E

A B CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

RP

F

D


PIM Bidir Joining

Router “B” Creates (*, G) State

Receiver 2

E

A CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

RP

F

D



B


PIM Bidir Joining

Router “B” Sends (*, G) Join to “E” (DF) Causing It to Create (*, G) State


Receiver 2

A B CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

RP

D

F

(*, 224.1.1.1), 00:00:49/00:02:41, RP 172.16.21.1, flags: BBidir-Upstream: Ethernet0, RPF nbr 172.16.1.1Outgoing interface list:


E


PIM Bidir Joining


Router “E” Sends (*, G) Join to “RP” (State on RP Remains Unchanged)

Receiver 2

E

A B CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

D

F(*, 224.1.1.1), 00:13:49/00:03:29, RP 172.16.21.1, flags: B

Bidir-Upstream: Null, RPF nbr 0.0.0.0Outgoing interface list:


RP


PIM Bidir Joining

New Branch of Shared Tree Is Built to Receiver 2

Receiver 2

A CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

E

B

F

D

RP


PIM Bidir Sending

Source

Arriving Traffic from Source Causes Router “A” to Create (*, G) State

Receiver 2

CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

E

B

F

D

(*, 224.1.1.1), 00:32:20/00:02:59, RP 172.16.21.1, flags: BPBidir-Upstream: Ethernet0, RPF nbr 172.16.7.1Outgoing interface list:

Ethernet0, Bidir-Upstream/Sparse-Dense, 00:32:20/00:00:00

RP

A


PIM Bidir Sending

Traffic Is Forwarded Toward Router “E” and Also Arrives at IIF of Router “B”

Source Receiver 2

CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

E F

DA B

RP


PIM Bidir Sending

Router “B” Forwards Traffic Back Down Shared Tree ala Normal PIM-SM

Source Receiver 2

CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

RP

E F

DA



B


PIM Bidir Sending

Router “E” Forwards Traffic on Toward RP

Source Receiver 2

CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

F

DA B

(*, 224.1.1.1), 00:32:20/00:02:59, RP 172.16.21.1, flags: BPBidir-Upstream: Ethernet0, RPF nbr 172.16.7.1Outgoing interface list:


E

RP


PIM Bidir Sending

Traffic Forwarded Toward RP also flows down existing branch to Rcvr 1

Source Receiver 2

CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

E

A B

F

D

RP


PIM Bidir Sending

Question: Does the RP even have to physically exist?Source Receiver 2

CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

E

A B

F

D

RP


PIM Bidir RP

Answer: No. It can just be a phantom address.

Source Receiver 2

CE1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E1 (DF)

E0

E0 (DF)

Receiver 1

E

A B

F

D

RP

Question: Does the RP even have to physically exist?


Recap: Common Multicast Flags - IOS S: Sparse Mode (in contrast to D for Dense Mode) s: SSM; only seen on (S,G) entries B: Bidir F: Register; set on First-Hop router P: Prune; entry has an empty OIL J: Join-SPT; (*,G) traffic exceeds SPT Threshold T: 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: Connected; the router has a directly connected receiver. I: Router Received Source Specific Host Report (SSM)

For YourReference


New PIM Model

For YourReference


PIM Old Model – IOS IPv4 (Simplified)

ADJ Table MET

MAC TableFIB TCAM

I/O Module

RouteProcessor

PIM MSDP

Mroute Table

IGMP

URIB

L2 Forwarding

Other HW

Hardware Drivers

IP FIB

L2 Forwarding Table

show ip mrouteshow ip mroute countshow ip igmp groupsshow ip msdp sa-cache

SA Cache

STP

Various hardware dependent show commands.

For YourReference


PIM New Model – IOS-XR exampleshow pim group-mapshow pim topology [sh ip mroute]show igmp groupsshow igmp snooping <xxx>show msdp sa-cache

show mrib route [sh ip mroute]

show mfib route [sh ip mroute]show mfib connectionsshow mfib counter

show mfib hardware route olist loc <>show mfib hardware connection loc <>show mfib hardware ltrace loc <>show mfib hardware interface loc <>

show controller np counters allshow controller np struct <id> allshow controller np summary all NP

PRM/uIDBNETIO

Line Card

SupervisorEngine

MSDP PIM

MRIB

IGMP

URIB

STP

MFIB

MFIB PI

MGID Server

MFIB PD

PIM Topology

HardwareDependent

L2FIB

L2FIB

Fabric

For YourReference


PIM New Model – NX-OS example

show ip pim topology [sh ip mroute]show ip pim route [sh ip mroute]show ip igmp route show ip igmp snooping groupsshow ip msdp route

show routing ip multicast [sh ip mroute]

show forwarding distribution ip multicast routeshow forwarding distribution ip igmp snooping

show forwarding ip multicast route

show system internal forwarding ip multicast routeshow system internal ip igmp snooping

ADJ Table MET

MAC TableFIB TCAM

I/O Module

SupervisorEngine

MSDP PIM

MRIB

IGMP

URIB

STP

MFDM

PIXMC

PIXM

IP FIB

Other HW

Hardware Drivers

L2MCAST

PIM Topology

HardwareDependent

For YourReference


PIM Topology Table Example – XR

RP/0/5/CPU0:rtr#sh pim topology 225.1.1.1

Fri Sep 16 12:49:18.533 CESTIP PIM Multicast Topology TableEntry state: (*/S,G)[RPT/SPT] Protocol Uptime InfoEntry flags: KAT - Keep Alive Timer, AA - Assume Alive, PA - Probe AliveRA - Really Alive, IA - Inherit Alive, LH - Last HopDSS - Don't Signal Sources, RR - Register ReceivedSR - Sending Registers, E - MSDP External, EX - ExtranetDCC - Don't Check Connected, ME - MDT Encap, MD - MDT DecapMT - Crossed Data MDT threshold, MA - Data MDT group assignedInterface state: Name, Uptime, Fwd, InfoInterface flags: LI - Local Interest, LD - Local Dissinterest,II - Internal Interest, ID - Internal Dissinterest,LH - Last Hop, AS - Assert, AB - Admin Boundary, EX – Extranet

(*,225.1.1.1) SM Up: 5w2d RP: 192.168.0.3*JP: Join(never) RPF: Decapstunnel1,192.168.0.3 Flags:GigabitEthernet0/0/0/0 5w2d fwd Join(00:03:20)

(192.168.1.18,225.1.1.1)RPT SM Up: 00:00:09 RP: 192.168.0.3*JP: Prune(never) RPF: Decapstunnel1,192.168.0.3 Flags: KAT(00:03:21) RA DCC RR (00:04:22)GigabitEthernet0/0/0/0 00:00:09 off Prune(00:03:20)

(192.168.1.18,225.1.1.1) SM Up: 00:07:51JP: Null(never) RPF: GigabitEthernet0/0/0/1,192.168.1.5 Flags: KAT(00:03:21) RA DCC RR (00:04:22)No interfaces in immediate olist

For YourReference


PIM Topology Table Entry Flags/TimersEntry 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 routeLH 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 ReceivedSR Sending Registers PIM Register Messages are being SentE MSDP External (S,G) learned from MSDP Peer

DCC Don't Check Connected Don't check for directly connected Sources

Interface FlagsFlag/Timer Name Description

Join() Join Timer Countdown timer. Time until Interface Join Times OutPrune() 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 InterfaceAB Admin Boundary Interface would be in olist but it is blocked by Admin Boundary.

For YourReference


PIM MRIB State Example – XR

RP/0/5/CPU0:rtr#show mrib route

IP Multicast Routing Information BaseEntry 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 handleCD - 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 InterfaceEI - Encapsulation Interface, MI - MDT Interface, LVIF - MPLS Encap,EX - Extranet

(*,225.0.0.0) RPF nbr: 0.0.0.0 Flags: CUp: 00:02:13Outgoing Interface List

GigabitEthernet0/2/1/0.102 Flags: F NS, Up: 00:02:13

(192.2.1.2,225.0.0.0) RPF nbr: 192.2.1.2 Flags:Up: 00:00:07Incoming Interface List

GigabitEthernet0/2/1/1 Flags: A, Up: 00:00:07Outgoing Interface List

GigabitEthernet0/2/1/0.102 Flags: F NS, Up: 00:00:07

For YourReference


MRIB Entry FlagsEntry Flags

Flag/Timers Name Description

UP Entry Up Timer Time Entry has existedC Directly-Connected Check Perform check on incoming packets applicable to this Entry.S Signal Signal PIM.IA Inherit Alive Inherit Alive Interfaces from Parent routeIF Inherit FromD Drop

MA MDT Address MVPN MDT Tunnel Address (Multicast Address)ME MDT Encapsulate Encapsulate in MDT TunnelMD MDT Decapsulate Decapsulate from MDT TunnelMT Crossed Data MDT Threshold (S,G) traffic has crossed Data MDT Threshold.MH MDT interface handle Interface used for MVPN MDT Tunnel

Interface FlagsFlag/Timers Name Description

UP Interface Up Timer Time Interface has existed in Outgoing Interface ListF Forward Forward multicast packets on this interfaceA Accept Accept multicast packets on this interfaceIC Internal CopyNS Negate Signal Invert Signal status of Entry for this interface. (Often means "Signal".)DP Don't PreserveSP 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 YourReference


• White Papers

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More Information

RTFB = “Read the Fine Book”


Multicast Bedtime Stories

Documents

IP Multicast Survival Guide Part 2 - DFW Cisco User Group · 2016. 4. 6. · IP Multicast Survival Guide II -2. nd. Edition-rev6.pptx 3. To provide a “deep dive” into PIM ASM