The following steps outline the procedure for discovering the network
configuration of a router or multilayer switch.

Step 1
View the name and model of the device, as well as the
version of operating system that the device is running.
Step 2
Determine active interfaces and their addresses.
- Enter show ip interfaces.
Step 3
View a brief summary of the interfaces on the device
including the IP address, interface name, media type, status of the
configuration, and physical and data link operational status.
- Enter show ip interfaces brief.
Step 4
View the MAC address for any interface or port.
- Enter show ip interface {interface-name} for
each interface or enter show interfaces to see a list of
all interfaces at once.
Step 5
View a summary of both the IP and non-IP routing
protocols enabled for the device.
Step 6
View details about the spanning tree status on the
device.
- Depending on the IOS version, enter show spanning-tree
, show spanning-tree summary or show
spantree.
Step 7
View a list of directly connected Cisco devices.
- Enter show cdp neighbors [detail], or if cdp is
disabled, enter ping.
Step 8
View details about any connected devices such as IP
address and capabilities.
- Enter show cdp entry {device id}, show
ip eigrp neighbors, or show ip ospf
neighbor.
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NOTE:
If CDP is disabled, you may want to enable CDP temporarily to make it
easier to discover information about neighboring devices. However, enabling CDP
on your devices does not guarantee that the neighboring devices will have CDP
enabled.
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The following steps outline the procedure for discovering the network
configuration of a Layer 2 switch.

Step 1
View the name and model of the device, as well as the
version of operating system that the device is running.
Step 2
Determine active ports and their addresses.
Step 3
View a summary of the ports on the device including
port names, port status, duplex, and speed.
- Enter show interfaces status.
Step 4
View a summary of the EtherChannel configuration on
the device.
- Enter show etherchannel summary.
Step 5
View a summary of the trunk status of any ports that
are in trunking mode.
- Enter show interfaces trunk.
Step 6
View details about the spanning tree status on the
device.
- Depending on the IOS version, enter show spanning-tree
or show spantree.
Step 7
View a list of directly connected Cisco devices.
- Enter show cdp neighbors.
Step 8
View details about any connected devices such as IP
address and capabilities.
- Enter show cdp entry {entry name} or
show cdp neightbor [detail].
All this information can be displayed using the command show
tech-support. However, the output from this command will generate a
lot more information than is actually needed.