Traceroute Mac - Cisco Catalyst 3750 Command Reference Manual

Chapter 2 Catalyst 3750 Switch Cisco IOS Commands

traceroute mac

Use the traceroute mac privileged EXEC command on the switch stack or on a standalone switch to
display the Layer 2 path taken by the packets from the specified source MAC address to the specified
destination MAC address.
Syntax Description interface interface-id
source-mac-address
destination-mac-address
vlan vlan-id
detail
Defaults There is no default.
Command Modes Privileged EXEC
Command History Release
12.1(14)EA1
Usage Guidelines
For Layer 2 traceroute to function properly, Cisco Discovery Protocol (CDP) must be enabled on all the
switches in the network. Do not disable CDP.
When the switch detects a device in the Layer 2 path that does not support Layer 2 traceroute, the switch
continues to send Layer 2 trace queries and lets them time out.
The maximum number of hops identified in the path is ten.
Layer 2 traceroute supports only unicast traffic. If you specify a multicast source or destination MAC
address, the physical path is not identified, and an error message appears.
The traceroute mac command output shows the Layer 2 path when the specified source and destination
addresses belong to the same VLAN. If you specify source and destination addresses that belong to
different VLANs, the Layer 2 path is not identified, and an error message appears.
If the source or destination MAC address belongs to multiple VLANs, you must specify the VLAN to
which both the source and destination MAC addresses belong. If the VLAN is not specified, the path is
not identified, and an error message appears.
The Layer 2 traceroute feature is not supported when multiple devices are attached to one port through
hubs (for example, multiple CDP neighbors are detected on a port). When more than one CDP neighbor
is detected on a port, the Layer 2 path is not identified, and an error message appears.
78-16181-03
traceroute mac [interface interface-id] {source-mac-address} [interface interface-id]
{destination-mac-address} [vlan vlan-id] [detail]
(Optional) Specify an interface on the source or destination switch.
Specify the MAC address of the source switch in hexadecimal format.
Specify the MAC address of the destination switch in hexadecimal format.
(Optional) Specify the VLAN on which to trace the Layer 2 path that the
packets take from the source switch to the destination switch. Valid VLAN
IDs are from 1 to 4094.
(Optional) Specify that detailed information appears.
Modification
This command was introduced.
Catalyst 3750 Switch Command Reference
traceroute mac
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