Network Configuration Documentation
Discovering network configuration information

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.

  • Enter show version.

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.

  • Enter show ip protocols.

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.
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.

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.

  • Enter show version.

Step 2
Determine active ports and their addresses.

  • Enter show interfaces.

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.