UMN:CLI User Manual
V5808
458
substantially reduce the network latency.
When the switching option is enabled, once multicast traffic from sources arrives at the
DR, the switchover to the SPT then occurs. This option only provides the binary option,
meaning that the switching to the SPT occurs either when receiving the first multicast
packet, or not at all; it is not rate-based. You can enable this option only for specified
multicast groups using access lists.
To enable the switchover to the SPT, use the following command.
Enables the switchover to SPT.
ip pim spt-threshold group-list
{<1-99> | <1300-1999> | WORD}
Enables the switchover to SPT for specified multicast
groups.
1-99: IP standard access list
1300-1999: IP standard access list (extended range)
WORD: access list name
To disable the switchover to the SPT, use the following command.
Disables the switchover to SPT.
no ip pim spt-threshold group-
list {<1-99> | <1300-1999> |
WORD}
The switchover to the SPT to deliver multicast traffic is disabled by default.
9.3.3.5 Cisco’s Router Interoperability
Register Message Checksum
When a multicast source registers with the RP, the DR encapsulates the multicast traffic
from the source in the PIM register message, and unicasts it to the RP. The standard PIM
protocol specifies that the checksum field in the register message contains the checksum
for the entire register message excluding the data portion, the encapsulated multicast
traffic.
The Cisco’s routers, however, validate the checksum for the whole register message
including the data portion, resulting in incompatibility with the standard-based routers. To
guarantee compatibility with the Cisco’s routers, the V5808 provides the checksum option,
which expands the range of the checksum calculation.
To enable the Cisco checksum option, use the following command.
ip pim cisco-register-checksum
Enables the Cisco checksum option.
ip pim cisco-register-checksum
group-list {<1-99> | <1300-1999>
| WORD}
Enables the Cisco checksum option for specified
multicast groups.
1-99: IP standard access list