Dell N3200-ON EMC Networking N-Series Switches CLI Reference Guide version 6.7 - Page 721

Monitored traffic is encapsulated in the RSPAN VLAN on the reflector port on the source switch. On a source switch, when both an RSPAN VLAN and reflector port are configured on a trunk or general mode port with other VLANs, the interface can also carry traffic on the other VLANs. For example, an uplink interface (trunk port) can carry both the RSPAN traffic and other traffic. Do not configure the RSPAN VLAN as a native VLAN on interfaces other than the uplink/transit/downlink interfaces. Be sure to remove the RSPAN VLAN from ports on which mirrored traffic should not be encapsulated and transported. The RSPAN tag is not transmitted on the destination (probe) port. The CPU interface is not supported as a destination interface or a source interface for RSPAN. For VLAN mirroring, the source VLAN cannot be the same as the RSPAN VLAN. The source VLAN and the RSPAN VLAN cannot be configured on the same port. The source VLAN is monitored in the ingress direction only. Careful consideration to placement of source mirroring sessions will allow bidirectional traffic to be monitored. Another alternative is to use port mirroring and a VLAN ACL filter if duplicate packets are received on the probe device. The reflector port must be configured as the only member of the RSPAN VLAN on the source switch. Multiple source interfaces may mirror traffic onto the RSPAN VLAN on both source switches and transmit switches (but not the destination switch). Be aware that the RSPAN VLAN floods mirrored traffic in the RSPAN VLAN. If an intermediate switch mirrors traffic onto the RSPAN VLAN, the traffic is flooded to both the destination and the other sources. Configuration of an ACL on the reflector port may mitigate this behavior. The source interface must be configured as the only member of the RSPAN VLAN on the destination (probe) switch. Mirroring a source to the RSPAN VLAN on the destination switch is not supported. If an ACL filter is specified, the ACL must be created prior to its use in an RSPAN configuration. The ACL filter is configured on the source switch. ACL filters are internally configured as an egress ACL on the destination interface/reflector port. All the criteria in the ACL are marked with the mirror attribute (and the RSPAN VLAN) to match the mirrored traffic (including the implicit deny all). If configuring an egress ACL on the destination port, care must be taken with the ACL numbering to ensure the mirrored traffic is properly processed. Layer 2 Switching Commands 721