512
C
HAPTER
35: C
ONFIGURING
PIM-DM
operating IGMPv1 (each PIM router periodically broadcasts a hello message,
and the router with higher IP address is chosen to be the DR).
■
Graft Message: The host informs the router which multicast groups it wants to
join by a IGMP membership report message. At this time, the port sends a graft
message to the upstream router. After the upstream router receives a graft
message, it adds this port to the forwarding list of the multicast group.
■
Graft ACK Message: After the upstream router receives the graft message, it
needs to send graft acknowledgement (ACK) message to the downstream
router sending the graft message.
■
Prune Message: If the router interface forwarding list is empty, or the interface
forwarding list becomes empty, the prune message will be sent to the
upstream router to inform it to delete the downstream router from its interface
neighbor list.
■
Assert Message: A shared network segment can have two upstream routers
simultaneously. If both of them forward multicast packets to it, the
downstream routers of this network segment will probably receive two same
multicast packets. In order to avoid this condition, PIM-DM adopts the assert
message mechanism. If a router receives multicast packets at the forwarding
port of a shared LAN, it requires all the routers operating PIM-DM (group
address is 224.0.0.13) to send an assert message. The downstream routers
determine the winner by comparing the specific domains of the assert message
according to the relevant series of rules. The router with little message
preference wins. If the preference is the same, the router with the smaller
message metric value wins. If the message metric value is the same, the router
with the bigger IP address wins. The winner serves as the transmitter of the
network segment, while the loser sends an output interface prune message.
PIM-DM itself does not have a routing discovery mechanism, so it has to depend
on a specific unicast routing protocol. Thus the protocol implementation is quite
simple.
PIM-DM Configuration
PIM-DM configuration includes tasks that are described in the following sections:
■
Enabling Multicast Routing
■
Starting the PIM-DM Protocol
■
Configuring the Time Interval for Hello Messages
Enabling Multicast
Routing
Only after the multicast routing is enabled, can routers receive multicast packets.
Make the following configuration in the system view.
Table 583
Enable Multicast Routing
By default, the system disables the multicast routing.
Operation
Command
Enable multicast routing
multicast routing-enable
Disable multicast routing
undo multicast routing-enable
Summary of Contents for Router 3032
Page 1: ...http www 3com com 3Com Router Configuration Guide Published March 2004 Part No 10014299...
Page 4: ...VPN 615 RELIABILITY 665 QOS 681 DIAL UP 721...
Page 6: ...2 ABOUT THIS GUIDE...
Page 7: ...I GETTING STARTED Chapter 1 3Com Router Introduction Chapter 2 3Com Router User Interface...
Page 8: ...4...
Page 16: ...12 CHAPTER 1 3COM ROUTER INTRODUCTION...
Page 34: ...30...
Page 60: ...56 CHAPTER 3 SYSTEM MANAGEMENT...
Page 98: ...94 CHAPTER 6 DISPLAY AND DEBUGGING TOOLS...
Page 110: ...106...
Page 114: ...110 CHAPTER 8 INTERFACE CONFIGURATION OVERVIEW...
Page 158: ...154 CHAPTER 10 CONFIGURING WAN INTERFACE...
Page 168: ...164...
Page 188: ...184 CHAPTER 13 CONFIGURING PPPOE CLIENT...
Page 192: ...188 CHAPTER 14 CONFIGURING SLIP Router ip route static 0 0 0 0 0 0 0 0 10 110 0 1...
Page 248: ...244 CHAPTER 16 CONFIGURING LAPB AND X 25...
Page 320: ...316...
Page 330: ...326 CHAPTER 20 CONFIGURING IP ADDRESS...
Page 362: ...358 CHAPTER 21 CONFIGURING IP APPLICATION...
Page 374: ...370 CHAPTER 23 CONFIGURING IP COUNT...
Page 406: ...402 CHAPTER 25 CONFIGURING DLSW...
Page 408: ...404...
Page 452: ...448 CHAPTER 29 CONFIGURING OSPF...
Page 482: ...478 CHAPTER 30 CONFIGURING BGP...
Page 494: ...490 CHAPTER 31 CONFIGURING IP ROUTING POLICY...
Page 502: ...498...
Page 508: ...504 CHAPTER 33 IP MULTICAST...
Page 514: ...510 CHAPTER 34 CONFIGURING IGMP...
Page 526: ...522 CHAPTER 36 CONFIGURING PIM SM...
Page 528: ...524...
Page 532: ...528 CHAPTER 37 CONFIGURING TERMINAL ACCESS SECURITY...
Page 550: ...546 CHAPTER 38 CONFIGURING AAA AND RADIUS PROTOCOL...
Page 590: ...586 CHAPTER 40 CONFIGURING IPSEC...
Page 599: ...IX VPN Chapter 42 Configuring VPN Chapter 43 Configuring L2TP Chapter 44 Configuring GRE...
Page 600: ...596...
Page 638: ...634 CHAPTER 43 CONFIGURING L2TP...
Page 649: ...X RELIABILITY Chapter 45 Configuring a Standby Center Chapter 46 Configuring VRRP...
Page 650: ...646...
Page 666: ...662...
Page 670: ...666 CHAPTER 47 QOS OVERVIEW...
Page 700: ...696 CHAPTER 49 CONGESTION MANAGEMENT...
Page 706: ...702 CHAPTER 50 CONGESTION AVOIDANCE...
Page 707: ...XII DIAL UP Chapter 51 Configuring DCC Chapter 52 Configuring Modem...
Page 708: ...704...
Page 762: ...758 CHAPTER 52 CONFIGURING MODEM...