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Catalyst 6500 Series Switch Command Reference—Release8.1
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Chapter2 Catalyst 6500 Series Switch and ROM Monitor Commands l2trace
l2trace
To display the Layer 2 path taken by the packets that start at a specified source address and end at a
specified destination address, use the l2trace command.
l2trace src_mac_addr dest_mac_addr [vlan] [detail]
l2trace src_ip_addr dest_ip_addr [detail]
Syntax Description
Defaults This command has no default settings.
Command Types Switch command.
Command Types Privileged.
Usage Guidelines All the intermediate devices should be Catalyst 5000 family or Catalyst 6500 series switches running
supervisor engine software release 6.1 or later. Catalyst 4500 series switches must be runni ng supervisor
engine software release 6.2 or later.
The l2trace command displays the Layer 2 path when the specified source and destination addresses
belong to the same VLAN. If you specify source and destinat ion ad dresse s tha t b elon g to di fferent
VLANs, l2trace aborts with an error message.
You must enable CDP on all the Catalyst 4500 series, Catalyst 5000 family, or Catalyst 6500 series
switches in the network.
When the switch detects a device (in the Layer 2 path) that does not b elong to the Catalyst 4500 series,
Catalyst 5000 family, or Catalyst 6500 series switches, the switch continues to send Layer 2 trace
queries and lets them time out.
This command is rejected if you enter a multicast source or destination MAC address.
If a source or the destination address belongs to multiple VLANs, you must specify the VLAN to be used for
determining the Layer 2 path.
src_mac_addr Source MAC address.
dest_mac_addr Destination MAC address.
vlan (Optional) Number of the VLAN.
src_ip_addr Source IP address or alias.
dest_ip_addr Destination IP address or alias.
detail (Optional) Specifies detailed information.