controlling campus device access configuring ip multicast
DESCRIPTION
Objectives Upon completion of this chapter, you will be able to perform the following tasks: Configure the primary distribution multilayer switch to forward multicast traffic using the PIM DM protocol Configure the primary distribution multilayer switch to forward multicast traffic using the PIM SM protocol Enable CGMP on the RSM and distribution layer switch Purpose: This graphic states the module objectives. Emphasize: Read or state each objective so each student has a clear understanding of the chapter objectives. At the end of this chapter, the students will be able to: Enable multicast routing on a network Configure an interface with Protocol Independent Multicast (PIM) Configure a candidate rendezvous point (RP) using Auto-RP Configure an RP-mapping agent Enable the Cisco Group Management Protocol (CGMP) on a router and a switch Verify the configuration Transition: The following discusses the Cisco IP multicast support products.TRANSCRIPT
© 1999, Cisco Systems, Inc. 10-1
Chapter 10
Controlling Campus Device Access
Chapter 10Configuring IP MulticastConfiguring IP Multicast
© 1999, Cisco Systems, Inc. 10-1
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-2
Objectives
Upon completion of this chapter, you will be able to perform the following tasks:• Configure the primary distribution multilayer
switch to forward multicast traffic using the PIM DM protocol• Configure the primary distribution multilayer
switch to forward multicast traffic using the PIM SM protocol• Enable CGMP on the RSM and distribution layer
switch
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-3
Configuring IP Multicast
In this chapter, we discuss the following topics:
• Planning for multicast• Configuring multicast services• Enhancing the route processor• Enabling CGMP
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-4
Configuring IP Multicast
In this section, we discuss the following topics:• Planning for Multicast—Planning for Multicast—Configuring IP Multicast Routing—Multicast Routing Protocol Types—Outgoing Interface Lists
• Configuring Multicast Services• Enhancing the Route Processor• Enabling CGMP
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-5
Switch Block
Planning Multicast
Core
Video Servers Host
IP Protocol Stack Supporting
Multicast
IP Protocol Stack Supporting
Multicast
IP Multicast Application
IP Multicast Application
NIC Card
Server Block Core Block
Access Switch
Distribution Switch
Distribution Switch
• All entities involved must be capable of identifying and supporting multicast traffic
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-6
End-to-End IP Multicast
• IP multicast routing protocols, Protocol Independent Multicast (PIM)
• Internet Group Management Protocol (IGMP)• Cisco Group Management Protocol (CGMP)
Core
VideoServers
Multicast RoutingProtocols (PIM)
Channel 1
Channel 2
Channel 3
CGMP
IGMPMBONE(DVMRP) 1
3
2
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-7
Enabling IP Multicast Routing
Router(config#ip multicast routing
Router>enableRouter#show running-configBuilding configuration...Current configuration:!hostname Router!!ip multicast-routing
• Enabling IP multicast routing allows the Cisco IOS software to forward multicast packets
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-8
Dense Mode
Receiver 1
B
E
A D F
Source
C
Receiver 2
No Receivers
• Floods everywhere initially• Prunes back where no group members• Prunes on redundant non-shortest path• Induces periodic reflooding
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-9
VLAN 45VLAN 43
Outgoing Interface Lists (Oilists)
Flood to all interfaces
First packet source (*,G)
VLAN 42
(*, 224.2.239.61), 00:29:21/00:02:59, RP 0.0.0.0, flags: DJC Incoming interface: Null, RPF nbr 0.0.0.0 Outgoing interface list: Vlan42, Forward/Dense, 00:07:01/00:00:00 Vlan43, Forward/Dense, 00:29:07/00:00:00 Vlan45, Forward/Dense, 00:29:07/00:00:00171.68.162.29/32, 224.2.239.61), 00:08:06/00:02:59, flags: CT Incoming interface: Vlan45, RPF nbr 172.16.51.3 Outgoing interface list: Vlan42, Forward/Dense, 00:07:02/00:00:00 Vlan43, Forward/Dense, 00:07:02/00:00:00(172.16.42.3/32, 224.2.239.61), 00:15:09/00:02:28, flags: PCT Incoming interface: Vlan42, RPF nbr 0.0.0.0 Outgoing interface list: Null
Subsequent packet source (S,G)
Flood all MC-enabled interfaces except the incoming interface
172.16.42.3
Prune Flag
Prune Statement
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Sparse Mode
• No one receives group traffic until a specific join• Rendezvous point queried• Sites pruned back permanently as needed• No periodic flooding as in dense-mode
Receiver 1
B
E
A D F
Source 1
C
Non-Viewer
Non-Viewers
Rendezvous Point
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-11
Sparse Mode Oilist
(*,G) Entry
RP IP AddressSparse Mode Join
Flag Set
Outgoing Interfaces
Incoming Interface
Prune Flag Is Set
(*, 224.2.253.119), 3d03h/00:02:59, RP 172.16.53.3, flags: SJC Incoming interface: null, RPF nbr 0.0.0.0 Outgoing interface list: FastEthernet0/0, Forward/Sparse, 1d21h/00:02:13
(172.16.53.1, 224.2.253.119), 00:02:55/00:00:04, flags: PCT Incoming interface: FastEthernet0/0, RPF nbr 0.0.0.0 Outgoing interface list: Null
Indicates this router Is the RP
FA 0/0172.15.53.3
172.15.53.1
Source
Group G
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-12
Configuring IP Multicast
In this section, we discuss the following topics:• Planning for Multicast• Configuring Multicast Services— Configuring a PIM Interface— Choosing and displaying a PIM neighbor— Configuring a Rendezvous Point— Defining the scope of delivery
• Enhancing the Route Processor• Enabling CGMP
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-13
Configuring a PIM interface
Router(config)#interface vlan41Router(config-if)#ip pim sparse-dense
Router>enableRouter#show running-confighostname Router!ip multicast-routing(text deleted)interface Vlan101 ip address 172.16.1.41 255.255.0.0 ip pim sparse-dense-mode
• The multicast routing protocol must be specifically assigned to an interface
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-14
Verifying the PIM Interface Configuration
RSM144#show ip pim interface
Address Interface Mode Nbr Query DR Count Intvl172.16.1.144 Vlan1 Sparse-Dense 1 30 172.16.1.145172.16.41.144 Vlan41 Sparse-Dense 1 30 172.16.11.145172.16.42.144 Vlan42 Sparse-Dense 0 30 172.16.12.145172.16.43.144 Vlan43 Sparse-Dense 1 30 172.16.13.145172.16.44.144 Vlan44 Sparse-Dense 1 30 172.16.14.145172.16.51.144 Vlan51 Sparse-Dense 4 30 172.16.51.145172.16.52.144 Vlan52 Sparse-Dense 4 30 172.16.52.145
• The show ip pim interface command displays information about interfaces configured for PIM
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-16
Selecting a Designated Router 172.16.41.144PIM Router 2
Highest IP AddressElected as DR
PIM Query
172.16.41.143PIM Router 1
• PIM queries are multicast to the all-routers (224.0.0.2) multicast group address periodically (Default = 30 seconds)
• If the DR times-out, a new DR is elected
PIM Query
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-17
Selecting a Designated Router (cont.)
Designated Router
• Only the designated router sends host query messages on a LAN
• All PIM routers on a single subnet receive replies from the host
Host Query
Host Reply
PIMRouter
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-18
Displaying the PIM Neighbor Table
RSM145>show ip pim neighborPIM Neighbor TableNeighbor Address Interface Uptime Expires Mode
172.16.51.143 FastEthernet1/0 2d02h 00:01:08 v1 Sparse-Dense172.16.51.144 FastEthernet1/0 3d01h 00:01:24 v1 Sparse-Dense (DR)172.16.51.143 FastEthernet1/0 3d01h 00:01:02 v1 Sparse-Dense172.16.51.144 FastEthernet1/0 3d01h 00:01:19 v1 Sparse-Dense172.16.52.143 FastEthernet2/0 2d02h 00:01:08 v1 Sparse-Dense172.16.52.144 FastEthernet2/0 3d01h 00:01:24 v1 Sparse-Dense (DR)172.16.52.143 FastEthernet2/0 3d01h 00:01:02 v1 Sparse-Dense172.16.52.144 FastEthernet2/0 3d01h 00:01:19 v1 Sparse-Dense
• The PIM neighbor table can be used to display the neighboring routers for a specific router
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-19
Configuring a Rendezvous Point
Router144(config)#ip pim rp-address 176.16.36.116172.16.31.116Rendezvous Point
172.16.41.144Leaf Router
CampusNetwork
Router144#show runhostname Router(text deleted)!ip classlessip pim rp-address 176.16.31.116
Leaf Router
IPTV Server
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-20
Auto-RP
CampusNetwork
I would like to be the RP
for Group XYZ.I would like to be the RP
for Group ABC.
RP Mapping AgentRouter A
Router B
Router A is theRP for Group ABC and Router B is
is the RP for Group XYZ.
Designated Router
Designated Router
Designated Router
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-21
Configuring send rp-announce
Router(config)#ip pim send-rp-announce vlan101 scope 16
Router#show running-confighostname Router!!ip multicast-routing(text deleted)ip pim rp-address 172.16.1.116ip pim send-rp-announce vlan101 scope 16
• Auto-RP requires an RP announce command on the router
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-22
Well-Known Group224.0.1.39
Auto-RP Discovery
RP Mapping Agent
RP Candidate
Well-Known Group224.0.1.40
Designated Router
rp-announceMessage
rp-announceMessage
RP Candidate
rp-discoveryMessage
Designated Router
Designated Router
Well-Known Group224.0.1.40
Designated Router
Designated Router
Designated Router
rp-discoveryMessage
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-23
Router#show running-confighostname Router!!ip multicast-routing(text deleted)ip pim rp-address 172.16.1.116ip pim send-rp-discovery scope 16
Configuring send rp-discovery
Router(config)#ip pim send-rp-discovery scope 16
• A router must be explicitly configured as a mapping agent
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-24
interface Vlan101 ip address 172.16.1.113 255.255.255.0 ip pim sparse-dense-mode ip multicast ttl-threshold 16
Configuring ttl-threshold
Router(config)#interface vlan101Router(config-if)#ip multicast ttl-threshold 16
• Only multicast packets with a TTL greater than the interface TTL threshold are forwarded on the interface
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-25
Displaying the Multicast Routing Table
Host Entry
RSM114#show ip mrouteIP Multicast Routing TableFlags: D - Dense, S - Sparse, C - Connected, L - Local, P - Pruned R - RP-bit set, F - Register flag, T - SPT-bit set, J - Join SPTTimers: Uptime/ExpiresInterface state: Interface, Next-Hop or VCD, State/Mode
(*, 224.2.210.17), 00:30:17/00:02:59, RP 172.16.53.3, flags: SP Incoming interface: Vlan52, RPF nbr 172.16.52.3 Outgoing interface list: Null
(172.16.53.1/32, 224.2.210.17), 00:01:49/00:01:10, flags: PT Incoming interface: Vlan52, RPF nbr 172.16.52.3 Outgoing interface list: Null
(*, 224.0.1.39), 00:29:22/00:02:59, RP 0.0.0.0, flags: SJP Incoming interface: Null, RPF nbr 0.0.0.0 Outgoing interface list: Null
Source Entry
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-28
Logging Multicast Packets
Address of the Packet Source
Receiving Interface
Multicast group address
Bytes in the Packet
Action Taken on the Packet
Router#debug ip mpacketIP multicast packets debugging is onRSM114#3d06h : IP: s=172.16.53.1 (Vlan51) d=224.2.210.17 len 60, mforward3d06h : IP: s=172.16.53.1 (Vlan52) d=224.2.210.17 len 60, mforward3d06h : IP: s=172.16.53.1 (Vlan51) d=224.0.1.24 len 65, mforward3d06h : IP: s=172.16.53.1 (Vlan52) d=224.0.1.24 len 65, mforward
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-29
Configuring IP Multicast
In this section, we discuss the following topics:• Planning for Multicast• Configuring Multicast Services• Enhancing the Route Processor— Joining a multicast group—Manipulating the IGMP version
• Enabling CGMP
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-30
Joining a Multicast Group
I am a member of Group 224.1.2.3.
I will answer that ping.
RSM144#show ip igmp int vlan41Vlan41 is up, line protocol is up Internet address is 172.16.41.144/24 IGMP is enabled on interface Current IGMP version is 2 (text deleted) Multicast designated router (DR) is 172.16.41.144 (this system) IGMP querying router is 172.16.41.143 Multicast groups joined: 224.0.1.40 224.0.1.39 224.1.2.3
CampusNetwork
Router#ping 224.1.2.3
Type escape sequence to abort.Sending 1, 100-byte ICMP Echos to 224.1.2.3, timeout is 2 seconds:
Reply to request 0 from 172.16.41.143, 1 ms
List of Group Memberships
IP Address of the Interface Servicing the
Group
172.16.41.143
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-31
IGMPv2 and IGMPv1 Devices in the Same Subnet
Leave to224.0.0.2
224.1.2.3
IGMPv1 Router
IGMPv1 Host1.2.3.11
I am configured as a IGMPv1 Router. I
will ignore any IGMPv2 leave
messages.
IGMPv1 Host1.2.3.12
IGMPv2 Host1.2.3.13
H3H1 H2
• Mixed-environment routers do not automatically detect the IGMP version of systems on the subnet and dynamically switch between versions
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-32
Determining the IGMP Version
Router#show ip igmp interfaceVlan101 is up, line protocol is up Internet address is 172.16.1.113, subnet mask is 255.255.255.0 IGMP is enabled on interface Current IGMP version is 2 CGMP is enabled on interface IGMP query interval is 60 seconds IGMP querier timeout is 120 seconds IGMP max query response time is 10 seconds Inbound IGMP access group is not set Multicast routing is enabled on interface Multicast TTL threshold is 16 Multicast designated router (DR) is 172.16.1.114 IGMP querying router is 172.16.1.113 (this system) Multicast groups joined: 224.0.1.40 224.0.1.39 224.1.2.3
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-33
Changing the IGMP Version
Router(config-if)#ip igmp version 1
interface Vlan41 ip address 172.16.411.143 255.255.255.0 ip pim sparse-dense-mode ip multicast ttl-threshold 16 ip igmp version 1
• The IGMP version has a default of 2
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-34
Configuring IP Multicast
In this section, we discuss the following topics:• Planning for Multicast• Configuring Multicast Services• Enhancing the Route Processor• Enabling CGMP— Enabling CGMP on the router— Enabling CGMP on the switch— Enable CGMP Leave
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-35
Enabling CGMP on the Router
Router#show run(text deleted)interface Vlan41 mac-address 4004.0114.0011 ip address 172.16.41.144 255.255.255.0 no ip redirects ip pim sparse-mode ip cgmp
CampusNetwork
Router(config-if)#ip cgmp 172.16.41.143
• CGMP is disabled by default• MP can only run on an interface if PIM is configured on the
same interface
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-36
CGMP — Joining a Group
0000.0c12.3456
I can reach device 000.0c12.3456 out of Port 2. I will add that port to group 224.1.2.3 in my switch forwarding table.
CGMP Join MAC Address 0000.0c12.3456 to224.1.2.3
0100.0cdd.dddd 0100.0cdd.dddd
I have no knowledge of
device 0000.0c12.3456
I am 0000.0c12.3456. I would like to join
multicast group224.1.2.3
To 224.0.0.2
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-37
Enabling CGMP on the Switch
Switch (enable)set cgmp enable
Switch (enable) show config (text deleted)#cgmpset cgmp enableset cgmp leave disable
• By default, CGMP is disabled on the switch
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-38
CGMP — Leaving a Group
• If router detects no members left in a multicast group, it sends a CGMP remove to all switches
0000.0c12.3456
I can reach device0000.0c12.3456out of Port 2. I will remove that port from group 224.1.2.3in my switchforwarding table.
CGMP Remove MAC Address 0000.0c12.3456 from224.1.2.3
0100.0cdd.dddd 0100.0cdd.dddd
I have no knowledge of
device 0000.0c12.3456
IGMPLeave to224.0.0.2
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-39
Enabling CGMP Leave on the Switch
Switch (enable) set cgmp leave enableCGMP leave processing enabled.
(text deleted)!#cgmpset cgmp enableset cgmp leave enable!
• CGMP leave is disabled by default
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-40
Verifying CGMP on the Switch
Switch (enable) show cgmp statistics 41CGMP enabledCGMP statistics for vlan 41:valid rx pkts received 211915invalid rx pkts received 0valid cgmp joins received 211729valid cgmp leaves received 186valid igmp leaves received 0valid igmp queries received 3122igmp gs queries transmitted 0igmp leaves transmitted 0failures to add DSW144 to RTR144 0topology notifications received 80number of CGMP packets dropped 2032227
• CGMP statistics display only the information that has been learned automatically through CGMP
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-41
Laboratory Exercise: Visual Objective
A
Multicast StreamGroup 224.2.163.21
B
Multicast StreamGroup 224.2.229.95
Multicast Group 224.2.229.95 Member
Multicast Group 224.2.163.21 Member
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-42
Summary
• Cisco multicast switches and routers support the PIM, IGMP, CGMP, and DVMRP protocols.• The DR is responsible for maintaining a current status
of group membership on a LAN. • The mode in which an interface is configured
determines how the routing table is populated and packets are forwarded.• The presence or absence of an RP determines how a
sparse-dense mode interface will react • Auto-RP facilitates the use of multiple RP in a network• CGMP leverages IGMP information to make Layer 2
forwarding decisions.
© 1999, Cisco Systems, Inc. www.cisco.com BCMSN—10-43
Review
• Discuss the basic tasks required to set up a multicast session within the network.• Describe the three PIM modes. • Explain how Auto-RP automates the distribution of
group-to-RP mappings in a network.• Discuss how CGMP leverages IGMP information to
facilitate Layer 2 forwarding decisions.