Cisco Systems WSC2960X24PSL, WSC2960X24TDL, WSC2960X48TSL, WSC2960X24TSLL, WSC2960X24PDL Rspan Vlan

Configuring SPAN and RSPAN

SPAN and RSPAN

configuration. If a configuration change is made to the port while it is acting as a SPAN destination port, the change does not take effect until the SPAN destination configuration had been removed.

Note When QoS is configured on the SPAN destination port, QoS takes effect immediately.

•If the port was in an EtherChannel group, it is removed from the group while it is a destination port. If it was a routed port, it is no longer a routed port.

•It can be any Ethernet physical port.

•It cannot be a secure port.

•It cannot be a source port.

•It cannot be an EtherChannel group or a VLAN.

•It can participate in only one SPAN session at a time (a destination port in one SPAN session cannot be a destination port for a second SPAN session).

•When it is active, incoming traffic is disabled. The port does not transmit any traffic except that required for the SPAN session. Incoming traffic is never learned or forwarded on a destination port.

•If ingress traffic forwarding is enabled for a network security device, the destination port forwards traffic at Layer 2.

•It does not participate in any of the Layer 2 protocols (STP, VTP, CDP, DTP, PagP).

•A destination port that belongs to a source VLAN of any SPAN session is excluded from the source list and is not monitored.

•The maximum number of destination ports in a switch or switch stack is 64.

Local SPAN and RSPAN destination ports function differently with VLAN tagging and encapsulation:

•For local SPAN, if the encapsulation replicate keywords are specified for the destination port, these packets appear with the original encapsulation (untagged, ISL, or IEEE 802.1Q). If these keywords are not specified, packets appear in the untagged format. Therefore, the output of a local SPAN session with encapsulation replicate enabled can contain a mixture of untagged, ISL, or IEEE 802.1Q-tagged packets.

•For RSPAN, the original VLAN ID is lost because it is overwritten by the RSPAN VLAN identification. Therefore, all packets appear on the destination port as untagged.

RSPAN VLAN

The RSPAN VLAN carries SPAN traffic between RSPAN source and destination sessions. RSPAN VLAN has these special characteristics:

•All traffic in the RSPAN VLAN is always flooded.

•No MAC address learning occurs on the RSPAN VLAN.

•RSPAN VLAN traffic only flows on trunk ports.

•RSPAN VLANs must be configured in VLAN configuration mode by using the remote-spanVLAN configuration mode command.

	Catalyst 2960-X Switch Network Management Configuration Guide, Cisco IOS Release 15.0(2)EX
74	OL-29044-01