FS S5900-24S4T2Q User manual

S5900-24S4T2Q SWITCH MULTICAST CONFIGURATION
Multicast Configuration
Model: S5900-24S4T2Q

S5900-24S4T2Q SWITCH MULTICAST CONFIGURATION
Table of Contents
1. Multicast Overview.......................................................................................................................................................................................1
1.1 Multicast Routing Realization....................................................................................................................................................................1
1.2 Multicast Routing Configuration Task List................................................................................................................................................ 2
1.2.1 Basic Multicast Configuration Task List........................................................................................................................................... 2
1.2.2 IGMP Configuration Task List........................................................................................................................................................... 2
1.2.3 PIM-DM Configuration Task List.......................................................................................................................................................2
1.2.4 PIM-SM Configuration Task List....................................................................................................................................................... 2
2. Basic Multicast Routing Configuration...................................................................................................................................................... 3
2.1 Starting up Multicast Routing...................................................................................................................................................................3
2.2 Starting up the Multicast Function on the Port........................................................................................................................................3
2.2.1 Starting up PIM-DM........................................................................................................................................................................ 3
2.2.2 Starting up PIM-SM...........................................................................................................................................................................3
2.3 Configuring TTL Threshold...................................................................................................................................................................... 3
2.4 Cancelling Rapid Multicast Forwarding...................................................................................................................................................3
2.5 Configuring Static Multicast Route..........................................................................................................................................................4
2.6 Configuring IP Multicast Boundary..........................................................................................................................................................4
2.7 Configuring IP Multicast Rate Control..................................................................................................................................................... 5
2.8 Configuring IP Multicast Helper...............................................................................................................................................................5
2.9 Configuring Stub Multicast Route........................................................................................................................................................... 6
2.10 Monitoring and Maintaining Multicast Route....................................................................................................................................... 7
3. IGMP Configuration......................................................................................................................................................................................8
3.1 Overview.................................................................................................................................................................................................. 8
3.2 IGMP Configuration..................................................................................................................................................................................8
3.2.1 Changing Current IGMP Version.................................................................................................................................................... 8
3.2.4 Configuring Maximum IGMP Response Time................................................................................................................................ 9
3.2.5 Configuring IGMP Query Interval for the Last Group Member......................................................................................................9
3.2.6 Configuring IGMP Query Interval for the Last Group Member....................................................................................................10
3.2.7 Configuring the IGMP Immediate-leave List..................................................................................................................................10
3.3 IGMP Characteristic Configuration Example......................................................................................................................................... 11
4. Basic Multicast Routing Configuration....................................................................................................................................................13
4.1 PIM-DM Introduction............................................................................................................................................................................. 13
4.2 Configuring PIM-DM.............................................................................................................................................................................. 13
4.2.1 Modifying Timer............................................................................................................................................................................13
4.2.2 Configuring State-Refresh............................................................................................................................................................ 14
4.2.3 Configuring Filtration List.............................................................................................................................................................14
4.2.4 Setting DR Priority........................................................................................................................................................................ 14
4.2.5 Clearing Item (S,G)........................................................................................................................................................................ 14
4.3 PIM-DM State-Refresh Configuration Example..................................................................................................................................... 15
5. Configuring PIM-SM...................................................................................................................................................................................15
5.1 PIM-SM Introduction.............................................................................................................................................................................. 15
5.2 Configuring PIM-SM...............................................................................................................................................................................16
5.2.1 Starting up PIM-SM....................................................................................................................................................................... 16
5.2.2 Configuring Static RP.................................................................................................................................................................... 16

S5900-24S4T2Q SWITCH MULTICAST CONFIGURATION
5.2.3 Configuring Candidate BSR.......................................................................................................................................................... 16
5.2.4 Configuring Candidate RP............................................................................................................................................................ 16
5.2.5 Displaying PIM-SM Multicast Route............................................................................................................................................. 17
5.2.6 Clearing Multicast Routes Learned by PIM-SM............................................................................................................................ 17
5.3 Configuration Example.......................................................................................................................................................................... 17
5.3.1 PIM-SM Configuration Example (The switch is configured on the VLAN port)........................................................................... 17
5.3.2 BSR Configuration Example (The switch is configured on the VLAN port)................................................................................. 18

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1. Multicast Overview
The chapter describes how to configure the multicast routing protocol. For the details of the multicast routing commands, refer to
the part "Multicast Routing Commands".
The traditional IP transmission allows only one host to communicate with a single host (unicast communication) or to communicate
with all hosts (broadcast communication). The multicast technology allows one host to send message to some hosts. These hosts
are called as group members.
The destination address of the message sent to the group member is a D-class address (224.0.0.0^239.255.255.255). The multicast
message is transmitted like UDP. It does not provide reliable transmission and error control as TCP does.
The sender and the receiver make up of a multicast application. The sender can send the multicast message without joining in a
group. However, the receiver has to join in a group before it receives the message from the group.
The relationship between group members is dynamic. The host can join in or leave a group at any time. There is no limitation to the
location and number of the group member. If necessary, a host can be a member of multiple groups. Therefore, the state of the
group and the number of group members varies with the time.
The router can maintain the routing table for forwarding multicast message by executing the multicast routing protocol such as
PIM-DM and PIM-SM. The router learns the state of the group members in the directly-connected network segment through IGMP.
The host can join in a designated IGMP group by sending the IGMP Report message.
The IP multicast technology is suitable for the one-to-multiple multimedia application.
1.1 Multicast Routing Realization
In the router software of our router, the multicast routing includes the following regulations:
IGMP runs between the router and the host in the LAN, which is used to track the group member relationship.
OLNK is a static multicast technology, which is used in the simple topology. It realizes the multicast forwarding and effectively
saves CPU and bandwidth.
PIM-DM, PIM-SM and DVMRP is dynamic multicast routing protocols. They run between routers and realizes the multicast
forwarding by creating the multicast routing table.
The following figure shows the multicast protocols used in the IP multicast applications.

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1.2 Multicast Routing Configuration Task List
1.2.1 Basic Multicast Configuration Task List
Starting up the multicast routing (mandatory)
Configuring TTL threshold (optional)
Canceling rapid multicast forwarding (optional)
Configuring static multicast route (optional)
Configuring multicast boundary (optional)
Configuring multicast helper (optional)
Configuring stub multicast route (optional)
Monitoring and maintaing multicast route (optional)
1.2.2 IGMP Configuration Task List
Modifying the current version of IGMP
Configuring the IGMP query interval
Configuring IGMP Querier interval
Configuring the maximum response time of IGMP
Configuring the query interval of the last IGMP group member
Static IGMP configuration
Configuring the IGMP Immediate-leave list
1.2.3 PIM-DM Configuration Task List
Regulating the timer
Designate the PIM-DM version
Configuring the state refreshment
Configuring the filtration list
Setting the DR priority
Clearing (S,G) information
1.2.4 PIM-SM Configuration Task List
Configuring static RP
Configuring standby BSR
Configuring standby RP
Displaying PIM-SM multicast routing
Clearing multicast routes learned by PIM-SM

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2. Basic Multicast Routing Configuration
2.1 Starting up Multicast Routing
To allow the router software to forward the multicast message, you must start up the multicast routing. Run the following
command in global configuration m ode to start up the multicast message forwarding:
Command
Purpose
ip multicast-routing
Starts up the multicast routing.
2.2 Starting up the Multicast Function on the Port
When the multicast routing protocol runs on a port, the IGMP is activated on the port. The multicast routing protocols include
OLNK, PIM-DM, PIM-SM and DVMRP. Only one multicast routing protocol is allowed to run on the same port. When the router
connects multiple multicast domains, different multicast protocols can be run on different ports.
Although the router software can function as the multicast boundary router (MBR). If possible, do not simultaneously run multiple
multicast routing protocols on the same router for some multicast routing protocols may be badly affected. For example, when
PIM-DM and BIDIR PIM-SM simultaneously run, confusion is to occur.
2.2.1 Starting up PIM-DM
Run the following command to run PIM-DM on a port and then activate the multicast dense mode function:
Command
Purpose
ip pim-dm
Enters the port where PIM-DM is running and then activates PIM-
DM multicast routing process in port configuration mode.
2.2.2 Starting up PIM-SM
To run PIM-DM on a port and activate the PIM-DM multicast, perform the following operation:
Command
Purpose
ip pim-sm
Enters a port where PIM-SM needs to run and then activates the
PIM-SM multicast routing process in port configuration mode.
2.3 Configuring TTL Threshold
Run the command ip multicast ttl-threshold to configure the TTL threshold of the multicast message that is allowed to pass the
port. Run the command no ip multicast ttl-threshold to use the default threshold value 1.
Example
The following example shows how the administrator configures the TTL threshold on a port:
interface ethernet 1/0
ip multicast ttl-threshold 200
2.4 Cancelling Rapid Multicast Forwarding
Run the command ip multicast mroute-cache to configure the rapid multicast forwarding function on a port. Run the command
no ip multicast mroute-cache to cancel the rapid multicast forwarding function.
Command
Purpose
ip multicast ttl-threshold ttl-value
Configures the TTL threshold on the port.

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Example
The following example shows how the administrator cancels the rapid multicast forwarding function on a port:
interface ethernet 1/0
no ip mroute-cache
2.5 Configuring Static Multicast Route
The static multicast route allows that the multicast forwarding path is different from the unicast path. RPF check is performed
when the multicast message is forwarded. The actual port receiving the message is the expected receiving port. That is, the port is
the next-hop port of the unicast route that reaches the sender. If the unicast topology is same to the multicast topology, RPF
check is reasonable. In some cases, the unicast path requires to be different from the multicast path.
Take the tunnel technology as an example. When a router in a path does not support the multicast protocol, the resolution is to
configure the GRE tunnel between two routers. In the following figure, each unicast router supports only the unicast message;
each multicast router supports only the multicast message. The source host sends the multicast message to the destination host
through MR1 and MR2. MR2 forwards the multicast message only when it is received through the tunnel. When the destination
host sends the unicast message to the source host, the tunnel is also used. When the tunnel technology is adopted, the message
transmission speed is slower than that of the direct message transmission.
After the static multicast routing is configured, the router can perform the RPF check according to the configuration information.
The RPF check is not based on the unicast routing table any more. Therefore, the multicast message goesthro u gh the tunnel,
while the unicast message does not go through the tunnel. The static multicast route only exists in the local place. It will not be
announced or forwarded.
Run the following command in global configuration mode to configure the static multicast route:
2.6 Configuring IP Multicast Boundary
Run the command ip multicast boundary to configure the multicast boundary for the port. Run the command no ip multicast
boundary to cancel the configured boundary. The commands used in the second configuration will replace the commands used
in the first configuration.
Command
Purpose
ip multicast mroute-cache
Enables the rapid multicast forwarding function on a port.
Command
Purpose
ip mroute source-address mask rpf-address type numbed distance]
Configures the static multicast route.

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Example
The following example shows how to configure the management boundary for a port:
interface ethernet 0/0
ip multicast boundary acl
ip access-list standard acl
permit 192.168.20.97 255.255.255.0
2.7 Configuring IP Multicast Rate Control
Run the command ip multicast rate-limit to limit the rate of receiving and sending the multicast message in a source/group range.
Run the command no ip multicast rate-limit to cancel the rate limitation.
Run the following command to limit the input rate of a multicast flow to n kbps.
Run the following command to limit the output rate of a multicast flow to n kbps
2.8 Configuring IP Multicast Helper
Run the command ip multicast helper-map to use the multicast route to connect two broadcast networks in the multicast
network. Run the command no ip multicast helper-map to cancel the command.
On the last-hop router connecting the destination broadcast network, perform the following operations:
Command
Purpose
ip multicast boundary access-list
Configures the multicast boundary for the port.
Command
Purpose
ip multicast rate-limit in group-list access-list^ source-list access-
list2 nkbps
Configures the maximum input rate limitation of the multicast
flow in a certain range.
Command
Purpose
ip multicast rate-limit out group-list access-list^ source-list access-
list2 kbps
Configures the maximum output cate limitation of the multicast
flow in a certain range.
Command
Purpose
interface type number
Enters the interface configuration mode.
ip multicast helper-map broadcast group-address access-list
Configures the command ip multicast helper to convert the
broadcast message to the multicast message.
ip directed-broadcast
Allows the directional broadcast
ip forward-protocol [port]
Configures the port number allowing to forward the message.
Command
Purpose
interface type number
Enters the interface configuration mode.
ip d i rected -b road cast
Allows the directional broadcast.

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Example
The following example shows how to configure the command ip multicast helper.
The configuration of the router is shown in the following figure. Configure the command ip directed-broadcast on the eO port of
the first-hop router to handle the directional message. Configure ip multicast helper-map broadcast 230.0.0.1 testacll, allowing to
convert the UDP broadcast message with port number 4000 that is sent from the source address 192.168.20.97/24 to the
multicast message with the destination address 230.0.0.1.
Configure the command ip directed-broadcast on the e1 port of the last-hop router to handle the directional message. Configure
ip multicast helper-map 230.0.0.1 172.10.255.255 testacl2, allowing to convert the multicast message with port number 4000 and
the destination address 230.0.0.1 that is sent from the source address 192.168.20.97/24 to the broadcast message with the
destination address 172.10.255.255.
In the first-hop router connecting the source broadcast network, perform the following operations: (the router is configured on
the VLAN port)
interface ethernet 0
ip directed-broadcast
ip multicast helper-map broadcast 230.0.0.1 testaci
ip pim-dm
!
ip access-list extended testa cl permit udp 192.168.20.97 255.255.255.0 any
ip forward-protocol udp 4000
In the last-hop router connecting the destination broadcast network, pe^oiTn the following operations:
interface ethernet 1
ip directed-broadcast
ip multicast helper-map 230.0.0.1 172.10.255.255 testacl2
ip pim-dm
!
ip access-list extended testacl2 permit udp 192.168.20.97 255.255.255.0 any
ip forward-protocol udp 4000
2.9 Configuring Stub Multicast Route
Run the commands ip igmp helper-address and ip pim-dm neighbor-filter to configure the Stub multicast route.
On the port where the stub router and the host are connected, perform the following operations:
On the port where the central router and the stub router are connected, perform the following operations:
ip multicast helper-map group-address broadcast-address access-
list
Configures the command ip multicast helper to convert the
multicast message to the broadcast message.
ip forward-protocol [port]
Configures the port number allowing to forward the message.
Command
Purpose
interface type number
Enters the interface configuration mode.
ip igmp helper-address destination-address
Configures the command ip igmp helper-address to forward the
multicast message to the central router.
Command
Purpose
interface type number
Enters the interface configuration mode.
ip pirn neighbor-filter access-list
Filters all pirn messages on the stub router.

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Example
The configuration of router A and B is shown as follows:
Stub Router A Configuration
ip multicast-routing
ip pim-dm
ip igmp helper-address 10.0.0.2
Central Router B Configuration
ip multicast-routing
ip pim-dm
ip pim-dm neighbor-filter stubfilter
ip access-list stubfilter
deny 10.0.0.1
2.10 Monitoring and Maintaining Multicast Route
a. Clearing the multicast cache and the routing table
If special caches or the routing table is invalid, you need to clear its content. Run the following commands in management mode:
b. Displaying the multicast routing table and system statistics information
The detailed information about the IP multicast routing table, cache or database helps to judge how the resources are used and to
resolve network problems.
Run the following commands in management mode to display the statistics information about the multicast route:
Command
Purpose
clear ip igmp group [type number] [group-address \ <cr>]
Clears the items in the IGMP cache.
clear ip mroute [* \ group-address \ source-address]
Clears the items in the multicast routing table.
Command
Purpose
show ip igmp groups [type number \ group-address] [detail]
Displays the information about the multicast group in the IGMP
cache.
show ip igmp interface [type number]
Displays the IGMP configuration information on the interface.
show ip mroute mfc
Displays the multicast forwarding cache.
show ip rpf [ucast | mstatic | pim-dm | pim-sm | dvmrp] source-
address
Displays the RPF information.