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HAPTER
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| Port Mirroring Commands
Local Port Mirroring Commands
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vlan-id - VLAN ID (Range: 1-4093)
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
u No mirror session is defined.
u When enabled for an interface, default mirroring is for both received
and transmitted packets.
u When enabled for a VLAN or a MAC address, mirroring is restricted to
received packets.
COMMAND MODE
Interface Configuration (Ethernet, destination port)
COMMAND USAGE
u 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.
u 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.
u All VLAN mirror sessions must share the same target port, preferably
one that is not a member of the source VLAN.
u 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.
u 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.
u 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.
u Note that Spanning Tree BPDU packets are not mirrored to the target
port.
u 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.
u You can create multiple mirror sessions, but all sessions must share the
same destination port.
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