Netgear XCM8806 - 8800 SERIES 6-SLOT CHASSIS SWITCH ユーザーズマニュアル
Chapter 27. Multicast Routing and Switching
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NETGEAR 8800 User Manual
rtlookup [<ipaddress> | <ipv6address>] { unicast | multicast | rpf }
{ vr <vr_name> }
Displaying the PIM Snooping Configuration
To display the PIM snooping configuration for a VLAN, use the following command:
show pim snooping {vlan} <name>
Troubleshooting PIM
The following sections introduce two commands that you can use to troubleshoot multicast
communications:
communications:
Multicast Trace Tool
The multicast trace tool is the multicast equivalent of unicast trace route mechanism and is
an effective tool for debugging multicast reachability problems. This tool is based on an IETF
draft and uses IGMP. Because it is harder to trace a multicast path from the source to the
destination, a multicast trace is run from the destination to the source. The multicast trace
can be used to do the following:
an effective tool for debugging multicast reachability problems. This tool is based on an IETF
draft and uses IGMP. Because it is harder to trace a multicast path from the source to the
destination, a multicast trace is run from the destination to the source. The multicast trace
can be used to do the following:
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Locate where a multicast traffic flow stops
•
Identify sub-optimal multicast paths
A multicast trace is used for tracing both potential and actual multicast forwarding tree paths.
When the multicast tree is established and traffic is flowing, this tool traces the actual traffic
flow. If there is no traffic while executing the command, this tool displays the potential path for
the group and source being traced.
When the multicast tree is established and traffic is flowing, this tool traces the actual traffic
flow. If there is no traffic while executing the command, this tool displays the potential path for
the group and source being traced.
You can direct a multicast trace to any network destination, which can be a multicast source
or destination, or a node located between a source and destination. After you initiate the
trace, a multicast trace query packet is sent to the last-hop multicast router for the specified
destination. The query packet contains the source address, group address,
destination/receiver address, response address, maximum number of hops, and TTL to be
used for the multicast trace response.
or destination, or a node located between a source and destination. After you initiate the
trace, a multicast trace query packet is sent to the last-hop multicast router for the specified
destination. The query packet contains the source address, group address,
destination/receiver address, response address, maximum number of hops, and TTL to be
used for the multicast trace response.
The previous hop router selection is based on the multicast routing protocol and the state for
the S,G entry in the processing router. For example:
the S,G entry in the processing router. For example:
•
If there is no S,G state in the router, the parent closest to the RP is chosen as the
previous hop.
•
If the S,G state exists in the router, the parent closest to the source is chosen as the
previous hop.