source: http://www.networksorcery.com/enp/protocol/ip/multicast.htm

Moving on to IPV6.

Some reading:

http://www.cisco.com/en/US/docs/ios/12_0/np1/configuration/guide/1cmulti.pdf

http://www.cisco.com/warp/public/cc/pd/iosw/prodlit/ipimt_ov.pdf

http://www.cisco.com/warp/public/cc/techno/tity/ipmu/tech/ipcas_dg.pdf

Multicast notes:

• class d 224.0.0.0/4 (224.0.0.0 – 239.255.255.255)
• reserved (like rfc 1918) – 224.0.0.0/24 (224.0.0.0 -224.0.0.255)
• Administratively Scoped Block  – 239.0.0.0-239.255.255.255

1. hello’s are sent every 30 sec to 224.0.0.13
2. loopback – ip ospf point-to-point for RPF check
3. (S,G) source tree / shortest path tree / source
   (*,G) shared tree / any source
4. holdtime = 3.5x the hello
5. highest IP wins DR
6. lowest IP wins designated querier
7. rp-address (unicast) must be advertised in unicast IGP
8. mtrace to group address to see the reverse path
9. traffic is always sent to the group address, never from.
10. the source ip is always a unicast ip address, never a mcast address.
11. igmp = router to client (automatically enabled with PIM)
12. pim = router to router ( relies on unicast routing domain, do make sure you have full igp connectivity)
13. sparse-mode – explicit join ( no traffic unless uyou request it) need’s an RP.
14. dense-mode – implicit join (gets all traffic unlexx you don’t want it), flood and prune
15. enabe mcast = ip multicast-routing (distributed on 3560)
16. (*,G) don’t care about the source.  (S,G) knows the source
    • incoming null / outgoing null – does not know the source.
17. Enable PIM on the shortest path to the Rp or you will get RFP failures.
18. switching from a shared tree (*,G) to a  shortest path tree (S,G) = SPT switchover
19. if theRPF fails the packet is dropped.
    • ping
    • sh ip mroute count
    • debup ip packet
    • ip mroute to rpf failure interface.
20. RP
    1. • auto -rp
         • ip pim sparse-dense
         • ip pim send-rp-announce loopback scope 16
           ip pim send-rp-discovery scope 16
         • p pim autorp listener – use when you have sparse-mode interfaces/all sparse mode router.
           
         • fallback to dense mode is he default, to prevent it use : ip pim dm-fallback.
         • 224.0.1.39 (announce) and 224.0.1.40(discovery)
         • Candidate RPs advertize their willingness to be an RP via “RP-announcement” messages. These messages are periodically sent to a reserved well-known group 224.0.1.39 (CISCO-RP-ANNOUNCE).
         • RP mapping agents join group 224.0.1.39 and map the RPs to the associated groups. The RP mapping agents advertise the authoritative RP-mappings to another well-known group address 224.0.1.40 (CISCO-RP-DISCOVERY). All PIM routers join 224.0.1.40 and store the RP-mappings in their private cache.
         • deny statements – the groul ill be negatively cached and run int dense mode.
         • control updates with ip multicast boundry
         • For the Auto-RP with Multiple RPs scenario, no load balancing is provided, and, when an RP changes, convergence is normally on the order of 3 minutes.
       • Bootstrap router
         • ip pim sparse-mode
           ip pim bsr-candidate
           ip pim rp-candidate
         • use hash to load balance
         • multiples overlapping RP’s = highest priority wins
         • control updates with ip pim bsr-border
    • static – ip pim rp-address – you need this on all the mcast devices.
      • override – will override AUTORP or BSR rp mappings.
    • dynamic – auto-rp (cisco prorietary)  or BSR
21. ip pim NBMA = use on hub in a FR network, to bypass split-horizon behavior.
22. GRE is the duct tape of routing!!!  makse your tunnel interfaces passive.
23. troubleshootin mcast:
    • 1  int s0/0 no ip mroute-cache -2- debup ip mpacket
    • debup ip pim
    • sh ip pim nei | rp | rp mapping | interface
    • sh ip pin int f0/0 detail
    • debup ip pim auto-rp <-shows you what RP is filtered.
    • sh run | in ip pim|int
    • keyword search under ip pim command reference
24. ip helper-map
    • convert from mcast group to broadcast
      • ip multi helper-map 224.1.1.1 150.100.200.255 111
      • acecss-list 111 oer udp host 150.100.255.1 a eq 39000
25. anycast – 2 RP’s with the same IP address’
    1. 
       
       

    • r1
      int lo0
      ip add 10.0.0.1 255.255.255.255
      int lo1
      ip add 10.1.1.1 255.255.255.255
      ip msdp peer 10.1.1.2 connect-sour loo1
      ip msdp originator-id loo1
      ip pim rp-address 1.1.1.1 [acl]

      r2
      int lo0
      ip add 10.0.0.1 255.255.255.255
      int lo1
      ip add 10.1.1.2 255.255.255.255
      ip msdp peer 10.1.1.1 connect-sour loo1
      ip msdp originator-id loo1
      ip pim rp-address 1.1.1.1 [acl]

ref: http://www.cisco.com/en/US/i/100001-200000/120001-130000/127001-128000/127866.jpg

sh ip pim interface
sh ip mroute
sh ip rpf 10.1.13.1  < – -after ping on another router to this one.

ip multicast rpf interval 15
ip multicast rpf interval 5 list 1  < — w/ acl
ip multicast rpf interval 5 ROUTEMAPFORGROUP < – route-map
———————

R1(config)#ip multicast route-limit 5 < — limit mroutes to 5

———————
R1(config)#do  sho ip pim int e0/0

Address          Interface                Ver/   Nbr    Query  DR     DR
Mode   Count  Intvl  Prior
10.1.13.1        Ethernet0/0              v2/D   1      30     1      10.1.13.3
R1(config-if)#int e0/0
R1(config-if)#ip pim dr-priority 10
R1(config-if)#do  sho ip pim int e0/0

Address          Interface                Ver/   Nbr    Query  DR     DR
Mode   Count  Intvl  Prior
10.1.13.1        Ethernet0/0              v2/D   1      30     10     10.1.13.1

———-

sh ip pim int e0/0  count

State: * – Fast Switched, D – Distributed Fast Switched
H – Hardware Switching Enabled
Address          Interface                FS  Mpackets In/Out
10.1.13.1        Ethernet0/0              *   2/0

——————–

R1(config-if)#do sho ip pim int e0/0

Address          Interface                Ver/   Nbr    Query  DR     DR
Mode   Count  Intvl  Prior
10.1.13.1        Ethernet0/0              v2/D   1      30     10     10.1.13.1

R1(config-if)#ip pim query-interval 60

R1(config-if)#do sho ip pim int e0/0

Address          Interface                Ver/   Nbr    Query  DR     DR
Mode   Count  Intvl  Prior
10.1.13.1        Ethernet0/0              v2/D   1      60     10    10.1.13.1

—————————————————————-

R6(config-if)#ip igmp join-group 224.1.1.1
sho ip igmp int
———————

troubleshooting  – I can not ping 224.1.1.1(r6) from r1

R1#mtrace 10.1.246.6
Type escape sequence to abort.
Mtrace from 10.1.246.6 to 10.1.13.1 via RPF
From source (?) to destination (?)
Querying full reverse path…
0  10.1.13.1
-1  10.1.13.1 PIM  [10.1.246.0/24]
-2  10.1.13.3 None No route

R1#ping 224.1.1.1

Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 224.1.1.1, timeout is 2 seconds:
.
R1#

R6(config-if)#do sho ip rpf 10.1.13.1
RPF information for ? (10.1.13.1)
RPF interface: Ethernet0/0
RPF neighbor: ? (10.1.246.4)
RPF route/mask: 10.1.13.0/24
RPF type: unicast (ospf 1)
RPF recursion count: 0
Doing distance-preferred lookups across tables
R6(config-if)#

R4(config-if)#do sho ip rpf 10.1.13.1
RPF information for ? (10.1.13.1)
RPF interface: Serial1/0.45
RPF neighbor: ? (10.1.45.5)
RPF route/mask: 10.1.13.0/24
RPF type: unicast (ospf 1)
RPF recursion count: 0
Doing distance-preferred lookups across tables

R5(config-if)#do sho ip rpf 10.1.13.1
RPF information for ? (10.1.13.1) failed, no route exists
R5(config-if)#

R5(config-if)#do sho ip rpf 10.1.13.1
RPF information for ? (10.1.13.1) failed, no route exists
R5(config-if)#do sho ip route 10.1.13.1
Routing entry for 10.1.13.0/24
Known via “ospf 1″, distance 110, metric 20, type intra area
Last update from 10.1.35.3 on Ethernet0/1, 00:44:06 ago
Routing Descriptor Blocks:
* 10.1.35.3, from 3.3.3.3, 00:44:06 ago, via Ethernet0/1
Route metric is 20, traffic share count is 1

R3#sh ip mroute 10.1.246.6 224.1.1.1
IP Multicast Routing Table
Flags: D – Dense, S – Sparse, B – Bidir Group, s – SSM Group, C – Connected,
L – Local, P – Pruned, R – RP-bit set, F – Register flag,
T – SPT-bit set, J – Join SPT, M – MSDP created entry,
X – Proxy Join Timer Running, A – Candidate for MSDP Advertisement,
U – URD, I – Received Source Specific Host Report,
Z – Multicast Tunnel, z – MDT-data group sender,
Y – Joined MDT-data group, y – Sending to MDT-data group
Outgoing interface flags: H – Hardware switched, A – Assert winner
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 224.1.1.1), 00:06:55/00:00:08, RP 0.0.0.0, flags: D
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Serial1/0.35, Forward/Dense, 00:06:55/00:00:00
Ethernet0/0, Forward/Dense, 00:06:55/00:00:00

THE PROBLEM IS THAT ON R5 mcast IS NOT TAKING THE right path. It should go the

way it came. ON r3 it shows that it learned about 224.1.1.1 from s1/0.35. But

R5 shows the path is through e0/1.

solution:
R5(config)#ip mroute 10.1.13.1 255.255.255.255 s1/0.53

R5(config)#do sho ip rpf 10.1.13.1
RPF information for ? (10.1.13.1)
RPF interface: Serial1/0.53
RPF neighbor: ? (10.1.100.3)
RPF route/mask: 10.1.13.1/32
RPF type: static
RPF recursion count: 0
Doing distance-preferred lookups across tables

r1 ping 224.1.1.1

R5(config)#do sho ip mroute 224.1.1.1
IP Multicast Routing Table
Flags: D – Dense, S – Sparse, B – Bidir Group, s – SSM Group, C – Connected,
L – Local, P – Pruned, R – RP-bit set, F – Register flag,
T – SPT-bit set, J – Join SPT, M – MSDP created entry,
X – Proxy Join Timer Running, A – Candidate for MSDP Advertisement,
U – URD, I – Received Source Specific Host Report,
Z – Multicast Tunnel, z – MDT-data group sender,
Y – Joined MDT-data group, y – Sending to MDT-data group
Outgoing interface flags: H – Hardware switched, A – Assert winner
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 224.1.1.1), 00:04:27/stopped, RP 0.0.0.0, flags: D
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Serial1/0.54, Forward/Dense, 00:04:27/00:00:00
Serial1/0.52, Forward/Dense, 00:04:27/00:00:00
Serial1/0.53, Forward/Dense, 00:04:27/00:00:00

(10.1.13.1, 224.1.1.1), 00:00:06/00:02:53, flags: T
Incoming interface: Serial1/0.53, RPF nbr 10.1.100.3, Mroute
Outgoing interface list:
Serial1/0.52, Prune/Dense, 00:00:06/00:02:53
Serial1/0.54, Forward/Dense, 00:00:06/00:00:00

******** SEND PINGS TO 224.1.1.1 to see output for some of these commands *****
——————————————————

R2(config)#ip pim rp-address 2.2.2.2 1
R2(config)#access-list 1 per 224.1.1.1

this is needed on all routers and I need to advertise 2.0.0.0/8 too so there is

route to the RP.

———————————————-

R6(config-if)#do sho ip pim rp
Group: 224.1.1.1, RP: 2.2.2.2, uptime 00:01:18, expires never
—————————————-

ip pim rp-address 5.5.5.5 5
access-list 5 per 224.5.5.5
——————————–

sho ip pim nei
—————–

R2(config)#ip pim send-rp-announce lo0 scope 6 interval 20

ttl = 6
interval= every 20 sec

access-list 26 per 224.26.26.26
ip pim send-rp-announce lo0 scope 6 group-list 26 in 20

r6 debug ip pim auto-rp
sh ip mroute 224.0.1.39
the routers who are config with the above cmds should be in the table.
———————————–

int lo 0
ip pim sparse-dense

ip pim send-rp-discovery loo0 scope 5 interval 10

sho ip mroute 224.0.1.40
IP Multicast Routing Table
Flags: D – Dense, S – Sparse, B – Bidir Group, s – SSM Group, C – Connected,
L – Local, P – Pruned, R – RP-bit set, F – Register flag,
T – SPT-bit set, J – Join SPT, M – MSDP created entry,
X – Proxy Join Timer Running, A – Candidate for MSDP Advertisement,
U – URD, I – Received Source Specific Host Report,
Z – Multicast Tunnel, z – MDT-data group sender,
Y – Joined MDT-data group, y – Sending to MDT-data group
Outgoing interface flags: H – Hardware switched, A – Assert winner
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 224.0.1.40), 06:09:59/stopped, RP 0.0.0.0, flags: DCL
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Loopback0, Forward/Sparse-Dense, 00:02:48/00:00:00
Serial1/0.54, Forward/Sparse-Dense, 06:09:59/00:00:00
Serial1/0.53, Forward/Sparse-Dense, 06:09:59/00:00:00
Serial1/0.52, Forward/Sparse-Dense, 06:09:59/00:00:00

(5.5.5.5, 224.0.1.40), 00:02:04/00:02:55, flags: LT
Incoming interface: Loopback0, RPF nbr 0.0.0.0
Outgoing interface list:
Serial1/0.52, Forward/Sparse-Dense, 00:02:04/00:00:00
Serial1/0.53, Forward/Sparse-Dense, 00:02:04/00:00:00
Serial1/0.54, Forward/Sparse-Dense, 00:02:04/00:00:00
r5 is forwarding rp-discovery out every interface.

———————

debug ip pim auto-rp
PIM Auto-RP debugging is on
R5(config)#int
*Mar  1 08:51:53.777: Auto-RP(0): Received RP-announce, from 6.6.6.6, RP_cnt 1, ht 61
*Mar  1 08:51:53.781: Auto-RP(0): Update (224.26.26.26/32, RP:6.6.6.6), PIMv2 v1
*Mar  1 08:51:53.785: Auto-RP(0): Received RP-announce, from 6.6.6.6, RP_cnt 1, ht 61
*Mar  1 08:51:53.793: Auto-RP(0): Update (224.26.26.26/32, RP:6.6.6.6), PIMv2 v1
*Mar  1 08:52:02.805: Auto-RP(0): Build RP-Discovery packet
*Mar  1 08:52:02.809: Auto-RP:  Build mapping (224.26.26.26/32, RP:6.6.6.6), PIMv2 v1,
*Mar  1 08:52:02.813: Auto-RP(0): Send RP-discovery packet on Ethernet0/1 (1 RP entries)
*Mar  1 08:52:02.813: Auto-RP(0): Send RP-discovery packet on Serial1/0.52 (1 RP entries)
*Mar  1 08:52:02.817: Auto-RP(0): Send RP-discovery packet on Serial1/0.53 (1 RP entries)
*Mar  1 08:52:02.821: Auto-RP(0): Send RP-discovery packet on Serial1/0.54 (1 RP entries)
*Mar  1 08:52:02.825: Auto-RP: Send RP-discovery packet on Loopback0 (1 RP entries)
————————

sh ip pim auto-rp

sh ip pim int count

State: * – Fast Switched, D – Distributed Fast Switched
H – Hardware Switching Enabled
Address          Interface                FS  Mpackets In/Out
10.1.5.5         Ethernet0/1              *   0/111
10.1.25.5        Serial1/0.52             *   1867/0
10.1.100.5       Serial1/0.53             *   0/433
10.1.45.5        Serial1/0.54             *   1/431
5.5.5.5          Loopback0                *   103/0
R5#
———————————————————

sho ip mroute 224.0.1.4
—————————————————–

filter r1 from r3

sho ip pim nei
PIM Neighbor Table
Neighbor          Interface                Uptime/Expires    Ver   DR
Address                                                            Prio/Mode
10.1.13.1         Ethernet0/0              09:26:18/00:01:28 v2    1 / S
10.1.100.5        Serial1/0.35             09:27:45/00:01:28 v2    1 / S

sh access-list

access-list 1 deny 10.1.13.1
———————> acl 1 per = is not needed here because all neighbor are allowed to

become neighbors anyway. <——————

int e0/0
ip pim neightbr-filter 1

sho ip pim nei
PIM Neighbor Table
Neighbor          Interface                Uptime/Expires    Ver   DR
Address                                                            Prio/Mode
10.1.100.5        Serial1/0.35             09:29:47/00:01:24 v2    1 / S

——————————–

if a filter is between r1 r5, on r3 one r1 int facing r3:

ip igmp helper-address 10.1.13.3
——————————————

sho ip pim rp

clear ip pim rp-mapping
——————————

before:
Group: 224.2.2.2, RP: 6.6.6.6, v2, v1, uptime 00:02:33, expires 00:00:27
Group: 224.4.4.4, RP: 6.6.6.6, v2, v1, uptime 00:02:33, expires 00:00:27
Group: 224.6.6.6, RP: 6.6.6.6, v2, v1, uptime 00:02:33, expires 00:00:27

ip pim send-rp-discovery Loopback0 scope 6 interval 10
ip pim rp-announce-filter rp-list R2 group-list R2-group
ip pim rp-announce-filter rp-list R4 group-list R4-group
ip pim rp-announce-filter rp-list R6 group-list R6-group

ip access-list standard R2
permit 2.2.2.2
ip access-list standard R2-group
permit 224.2.2.2
ip access-list standard R4
permit 4.4.4.4
ip access-list standard R4-group
permit 224.4.4.4
ip access-list standard R6
permit 6.6.6.6
ip access-list standard R6-group
permit 224.6.6.6

sho ip pim rp
Group: 224.2.2.2, RP: 2.2.2.2, v2, v1, uptime 00:01:43, expires 00:00:26
Group: 224.4.4.4, RP: 4.4.4.4, v2, v1, uptime 00:01:49, expires 00:00:03
Group: 224.6.6.6, RP: 6.6.6.6, v2, v1, uptime 00:01:12, expires 00:00:03
—————————————————————————-