Specifications

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Catalyst 4500 Se ries S wit ch C is co IO S C om mand R efer ence —Re lease I OS XE 3 .3.0 XO(1 5.1 (1)XO)
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Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
traceroute mac ip
traceroute mac ip
To display the Layer 2 path that is taken by the packets from the specified source IP address or hostname
to the specified destination IP address or hostname, use the traceroute mac command.
traceroute mac ip {source-ip-address | source-host name} {destination-ip-address |
destination-hostname} [detail]
Syntax Description
Defaults This command has no default settings.
Command Modes Privileged EXEC mode
Usage Guidelines For Layer 2 traceroute to functiona l properly, Cisco Discovery Protocol (CDP) must be enable d 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.
The traceroute mac ip comman d output shows the Layer 2 path whe n the specified source and
destination IP addresses are in the same subnet. When you specify the IP addresses, the switch uses
Address Resolution Protocol (ARP) to associate the IP addresse s with the correspondin g MAC addresses
and the VL AN I Ds.
• If an ARP entry exists for the specified IP address, the switch uses the associated MAC address and
identifies the physical path.
• If an ARP entry does not exist, the switch sends an ARP query and tries to resolve the IP address.
The IP addresses must be in the same subnet. If the IP address is not resolved, the path is not
identified, and a message appears.
Layer 2 traceroute 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 t han one CDP neig hbor is de tected
on a port, the Layer 2 path is not identified, and an error message appears.
This feature is not supported in Token Ring VLA Ns.
Examples This example shows how to display the Layer 2 path by specifying the source and destination IP
addresses and by using the detail keyword:
source-ip-address IP address of the source switch as a 32-bit quantity in dotted-decimal
format.
destination-ip-address IP address of the destination switch as a 32-bit quantity in dotted-decimal
format.
source-hostname IP hostname of the source switch.
destination-hostname IP hostname of the destination switch.
detail (Optional) Displays detailed traceroute MAC IP information.