HP 5500 Ei 5500 Si Switch Series Configuration Guide

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Figure 27  Changing an RPF route 
 
 
As shown in Figure 27, when no static multicast route is configured, Switch C’s RPF neighbor on the path 
back to Source is Switch A. The multicast information from Source travels along the path from Switch A 
to Switch C, which is the unicast route between the two routers. When a static multicast route is 
configured on Switch C and Switch B is configured  as Switch C’s RPF neighbor on the path back to 
Source, the multicast information from Source travels from...

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multicast route on Switch C and Switch D, specifying Switch B as the RPF neighbor of Switch C and 
specifying Switch C as the RPF neighbor of Switch D, the receivers can receive multicast data that the 
multicast source sent. 
 
  NOTE: 
•  Static multicast routes only affect RPF check but cannot guide multicast forwarding.  
•   A static multicast route is effective only on the multicast router on which it is confi
gured, and will not be
advertised throughout the network or redistributed to other...

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Task  Remarks 
Configuring multicast routing and 
forwarding Configuring static multicast routes 
Optional 
Configuring a multicast routing policy Optional 
Configuring a multicast forwarding range Optional  
Configuring the multicast forwarding table size Optional 
Tracing a multicast path Optional 
 
 IMPORTANT: 
IP multicast does not support secondary IP addre
ss segments. Namely, multicast can be routed and 
forwarded only through primary IP addresses even if  secondary addresses are configured...

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•  Configure a unicast routing protocol so that all  devices in the domain are interoperable at the 
network layer. 
•   Enable PIM (PIM-DM or PIM-SM). 
•   Determine the maximum number of downstream nodes  for a single multicast forwarding table entry. 
•   Determine the maximum number of entries in the multicast forwarding table. 
Configuring static multicast routes 
By configuring a static multicast route for a given multicast source, you can specify an RPF interface or an 
RPF neighbor for...

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Configuring a multicast routing policy in a VPN instance 
 
Step Command Remarks 
1.  Enter system view. 
system-view  N/A 
2.  Enter VPN instance view. 
ip vpn-instance vpn-instance-name  N/A 
3.  Configure the device to 
select the RPF route based 
on the longest match.  multicast longest-match  The route with the highest priority 
is selected as the RPF route by 
default. 
4.
  Configure multicast load 
splitting.  multicast load-splitting
 { source | 
source-group  }  Optional. 
Disabled by...

 80 
m a x i m u m  n u m b e r  o f  o u t g o i n g  i n t e r f a c e s ) ,  f o r  a  s i n g l e   entry in the multicast forwarding table to lessen the 
burden on the switch for replicating multicast traffic. If the configured maximum number of downstream 
nodes for a single multicast forwarding entry is smaller than the current number, the downstream nodes 
in excess are not deleted immediatel y. Instead, the multicast routing protocol that runs on the switch 
deletes them. The switch no longer...

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Displaying and maintaining multicast routing and 
forwarding 
 
Task Command Remarks 
Display multicast boundary 
information.  display multicast [ all-instance
 | vpn-instance 
vpn-instance-name  ] boundary [ group-address  [ mask | 
mask-length  ] ] [ interface  interface-type 
interface-number ] [ |  { begin | exclude  | include  } 
regular-expression  ]   Available in any 
view 
Display multicast 
forwarding table 
information. display multicast [ all-instance
 | vpn-instance 
vpn-instance-name...

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 IMPORTANT: 
The 
reset  command clears the information in the multicast routin
g table or the multicast forwarding table,
and thus might cause failure of multicast transmission. 
 
When a routing entry is deleted from the multicast routing table, the corresponding forwarding entry is 
also deleted from the multicast forwarding table. 
When a forwarding entry is deleted from the multicas t forwarding table, the corresponding routing entry 
is also deleted from the multicast routing table. 
For more...

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Enable OSPF on the switches in the PIM-DM domain. Ensure the network-layer interoperation 
among the switches in the PIM-DM  domain. Make sure that the switches can dynamically update 
their routing information by leveraging the unicast routing protocol. (Details not shown.)  
2.  Enable IP multicast routing, and enable PIM-DM and IGMP: 
# Enable IP multicast routing on Switch B, enable  PIM-DM on each interface, and enable IGMP on 
VLAN-interface 100. 
 system-view 
[SwitchB] multicast...

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# Use the  display multicast rpf-info  command to view the information about the RPF route to Source 
on Switch B.  
[SwitchB] display multicast rpf-info 50.1.1.100 
 RPF information about source 50.1.1.100: 
     RPF interface: Vlan-interface101, RPF neighbor: 20.1.1.2 
     Referenced route/mask: 50.1.1.0/24 
     Referenced route type: static multicast 
     Route selection rule: preference-preferred 
     Load splitting rule: disable 
The output shows that the RPF route on Switch B has changed....