Dell N1100-ON, Reference Manual

Page: 648 / 2332

Layer 2 Switching Commands
648
ports, and be members of the RSPAN VLAN. Do not assign other ports to the
RSPAN VLANs (for example, trunk ports that are not reflector ports).
Additionally, reflector ports may not be port channels.
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, except on the N4000, where the RSPAN tag appears
on the probe port due to hardware limitations.
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