C
HAPTER
29
| Port Mirroring Commands
Local Port Mirroring Commands
– 1018 –
vlan-id - VLAN ID (Range: 1-4094)
mac-address - MAC address in the form of xx-xx-xx-xx-xx-xx or
xxxxxxxxxxxx.
acl-name – Name of the ACL. (Maximum length: 16 characters, no
spaces or other special characters)
DEFAULT SETTING
â—† No mirror session is defined.
â—† When enabled for an interface, default mirroring is for both received
and transmitted packets.
â—† When enabled for a VLAN or a MAC address, mirroring is restricted to
received packets.
COMMAND MODE
Interface Configuration (Ethernet, destination port)
COMMAND USAGE
â—† You can mirror traffic from any source port to a destination port for
real-time analysis. You can then attach a logic analyzer or RMON probe
to the destination port and study the traffic crossing the source port in
a completely unobtrusive manner.
â—† Set the destination port by specifying an Ethernet interface with the
interface configuration command, and then use the port monitor
command to specify the source of the traffic to mirror.
â—† When mirroring traffic from a port, the mirror port and monitor port
speeds should match, otherwise traffic may be dropped from the
monitor port. When mirroring traffic from a VLAN, traffic may also be
dropped under heavy loads.
â—† When VLAN mirroring and port mirroring are both enabled, the target
port can receive a mirrored packet twice; once from the source mirror
port and again from the source mirror VLAN.
â—† When mirroring traffic from a MAC address, ingress traffic with the
specified source address entering any port in the switch, other than the
target port, will be mirrored to the destination port.
â—† Note that Spanning Tree BPDU packets are not mirrored to the target
port.
â—† When mirroring VLAN traffic or packets based on a source MAC
address, the target port cannot be set to the same target port as that
used for basic port mirroring.
â—† You can create multiple mirror sessions, but all sessions must share the
same destination port.
â—† The destination port cannot be a trunk or trunk member port.