Fabric OS Reference Manual (Version 3.0)

1-124 Fabric OS Reference

Telnet Commands

mcastShow

Display multicast routing information.

Synopsis mcastShow [group_ID]

Availability All users

Description Use this command to display the multicast routing information, as it is known by the FSPF path

selection and routing task, for all ports in the switch. The multicast routing information indicates,

for each multicast group, all the ports that are members of that group, that is ports that are able to

send and receive multicast frames on that group.

The multicast routing information is shown for all the multicast groups, or for a specific group if a

group ID is supplied.

Normally, an F_Port or FL_Port is a member of the multicast group only if it has joined the group

using the Alias Server protocol. On the other hand, E_Ports that are part of the multicast group are

selected by the multicast path selection protocol. They are chosen in a way that prevents multicast

routing loops.

The multicast paths are active for all the multicast groups at all times, regardless of whether a

multicast group contains any members.

The multicast routing information is shown as a set of bit maps. Each bit in the bit map represents a

port, with the least significant bit representing port 0. A bit set to 1 indicates that a port is part of the

multicast distribution tree.

The following fields are displayed:

Group Multicast group ID.

Member Ports Bit map of all ports in the multicast tree for that multicast group.

Member ISL Ports Bit map of all E_Ports in the multicast tree for that multicast group.

Static ISL Ports Reserved. It should be all zeroes.

Operands This command has the following operand:

group_ID Specify the multicast group to be displayed. This operand is optional.

Examples To display multicast routing information: