Resolution
These are the guidelines to configure Switched Port Analyzer (SPAN) on Cisco Intelligent Gigabit Ethernet Switch Module (CIGESM):
- SPAN sessions can coexist with Remote SPAN (RSPAN) sessions within specified limits.
- A destination port cannot be a source port, and a source port cannot be a destination port.
- There can be only one destination port for every SPAN session. Two SPAN sessions cannot use the same destination port.
- An EtherChannel port can be a SPAN source port, but not a SPAN destination port.
- For SPAN source ports, sent and received traffic can be monitored for a single port or for a series or range of ports.
- When a switch port is configured as a SPAN destination port, the port no longer remains a normal switch port. Only monitored traffic passes through the SPAN destination port.
- A disabled port can be configured as a source or destination port, but the SPAN function does not start until the destination port and at least one source port are enabled.
- A SPAN destination port never participates in any VLAN spanning tree. SPAN does include Bridge Protocol Data Units (BPDUs) in the monitored traffic. So any spanning-tree BPDUs received on the SPAN destination port for a SPAN session are copied from the SPAN source ports.
- When SPAN is enabled, these are the results of configuration changes:
- Any changes in the VLAN configuration of a destination port are not effective until SPAN is disabled.
- If the destination port or all source ports are disabled, the SPAN function stops until both a source and destination port are enabled.
For information on how to configure SPAN on CIGESM, refer to the Configuring SPAN section of Cisco IGESM Software Configuration Guide.
