To display the total number of RGMP groups, use the following command:

Coriolis> (enable) show rgmp group count [vlan]

Total Number of Entries = 2

Displaying RGMP−Capable Router Ports

To display the ports to which RGMP routers are connected, use the following command:

Coriolis> (enable) show multicast router rgmp PortVlan

—————————

2/1 +1 2/16 +2

Total Number of Entries = 2 ‘*’ − Configured

Displaying RGMP VLAN Statistics

To display RGMP statistics, use the following command:

Coriolis> (enable) show rgmp statistics 1

RGMP enabled

RGMP statistics for vlan <1>:

Receive:

Valid pkts:10

Hellos:5

Joins:3

Leaves:2

Byes:0

Discarded:0

Transmit:

Total Pkts:10

Failures:0

Hellos:10

Joins:

Leaves:0

Byes:0

You can reset the statistics with the command clear rgmp statistics.

Configuring GMRP

To enable GMRP globally, use the following command:

Coriolis> (enable) set gmrp enable

GMRP enabled.

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Disabling GMRP

To disable GMRP globally, use the following command:

Coriolis> (enable) set gmrp disable

GMRP disabled.

Enabling GMRP on Individual Ports

You can enable GMRP on a per−port basis using this command:

Coriolis> (enable) set port gmrp enable 2/1−12

GMRP enabled on ports 2/1−12.

But don’t be fooled—the switch will let you configure GMRP on a per−port basis, but it will not work unless you enable it globally.

Disabling GMRP on Individual Ports

To disable GMRP on each port, use the following command:

Coriolis> (enable) set port gmrp disable 2/1−12

GMRP disabled on ports 2/1−12.

Enabling GMRP Forward−All

When GMRP forward−all is enabled, a copy of all multicast traffic is forwarded to that port. You may want to use this feature when a probe or network analyzer is connected to a port. Cisco’s documentation recommends that you enable forward−all on any port that is connected to a router. Use this command to enable forward−all:

Coriolis> (enable) set gmrp fwdall enable 2/1

GMRP Forward All groups option enabled on port 2/1.

Disabling GMRP Forward−All

To disable GMRP forward−all on a port, use the following command:

Coriolis> (enable) set gmrp fwdall disable 2/1

GMRP Forward All groups option disabled on port 2/1.

Configuring GMRP Registration

GMRP registration has three modes:

∙Normal mode—Allows dynamic GMRP multicast registration and de−registration on the port.

∙Fixed mode—Registers all multicast group on all ports to this single port and ignores any subsequent registration and de−registration on other ports. To de−register any multicast group, you must first return the port to Normal mode.

∙Forbidden mode—Un−registers all GMRP multicasts and will not accept any GMRP multicast registration on that port.

To configure Normal mode, use the following command:

Coriolis> (enable) set gmrp registration normal 2/1

GMRP Registration is set normal on port 2/1.

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To configure Fixed mode, use the following command:

Coriolis> (enable) set gmrp registration fixed 2/1

GMRP Registration is set fixed on port 2/1.

To configure Forbidden mode, use the following command:

Coriolis> (enable) set gmrp registration forbidden 2/1

GMRP Registration is set forbidden on port 2/1.

Displaying the GMRP Configuration

To display the GMRP configuration setting on the switch, use the following command:

Coriolis> (enable) show gmrp configuration

Setting GMRP Timers

If you have many multicast groups, you can change the GMRP timer value to improve performance. The leave timer value must be equal to or greater than three times the join timer value. The leaveall timer value must be greater than the leave timer value.

You must change the timer values in this order: leaveall timer value, leave timer value, and then join timer value. If you try to set the join timer value before you change the leave timer value, an error message will result.

Let’s look at the commands to change the timer values:

Coriolis> (enable) set gmrp timer leaveall 8000

GMRP/GARP leaveAll timer value is set to 8000 milliseconds.

Coriolis> (enable) set gmrp timer leave 900

GMRP/GARP leave timer value is set to 900 milliseconds.

Coriolis> (enable) set gmrp timer join 300

GMRP/GARP join timer value is set to 300 milliseconds.

Displaying GMRP Timers

To display the GMRP timers, use the following command:

Coriolis> (enable) show gmrp timer

Tip

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GMRP and GARP are interchangeable for the set and show commands. GMRP is considered an alias of GARP.

Configuring Bandwidth−Based Suppression

Bandwidth−based suppression is a hardware−based suppression method. The threshold is set as a percentage of the port’s bandwidth. When the multicast/broadcast traffic exceeds the threshold within a one second period, the switch stops forwarding multicast/broadcast traffic. Unicast traffic will still be forwarded. Use the following command to configure bandwidth−based suppression:

Coriolis> (enable) set port broadcast 2/12 75%

Port(s) 2/12 broadcast traffic limited to 75%.

Configuring Packet−Based Suppression

Packet−based suppression is a software−based suppression method. The threshold is set as a number of packets traveling through the port. When the multicast/broadcast traffic exceeds the threshold within a one−second period, the switch stops all incoming traffic for the remainder of the period. Use the following command to configure packet−based suppression:

Coriolis> (enable) set port broadcast 2/12 500

Port(s) 2/12 broadcast traffic limited to 500 packets/second.

Disabling Multicast Suppression

Use the following command to disable both bandwidth−based and packet−based suppression:

Coriolis> (enable) clear port broadcast 2/12

Port 2/12 broadcast traffic unlimited.

Tip Bandwidth−based suppression is preferable to packet−based suppression. Packet sizes vary, and it is difficult to determine the right number of packets to specify for packet−based suppression. For example, you could have 500 small broadcast packets that used only 10 percent of the bandwidth—but a packet−based suppression value of 500 would still shut down the port.

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