Cisco Internetwork Troubleshooting Creating Network Configuration Documentation © 2005 Cisco Systems, Inc. All rights reserved. CIT v5.21-1

© 2005 Cisco Systems, Inc. All rights reserved. CIT v Network Configuration Tables When creating a network configuration table for troubleshooting, you should document the following: The device nameData link layer addresses and implemented featuresNetwork layer addresses and implemented features

© 2005 Cisco Systems, Inc. All rights reserved. CIT v Network Configuration Table Components Related to Troubleshooting Physical Layer CPU Type Flash Memory DRAM Media Types Speed Duplex WAN Circuits Interface Names Data Link Layer Device Name Device Model MAC Address Duplex Port Identifier STP State STP Route Bridge PortFast EtherChannel Spanning Tree VLANs Port Security Encapsulation Trunk Status Network Layer IP Address Secondary IP Address Subnet Mask IP Routing Protocol(s) Access Lists IP Addresses of Neighboring Devices Tunnels Loopbacks

© 2005 Cisco Systems, Inc. All rights reserved. CIT v Device Name, Model Interface Name MAC Address IP Address and Subnet Mask IP Routing Protocol(s) Etna, Cisco1760-V Vesuvius, Cisco2611XM fa0/0 fa0/1 s0/1 s1/1 s0/1 s1/ a a / / / / / /16 EIGRP 10 OSPF EIGRP 10 OSPF EIGRP 10 An Example of a Network Configuration Table (Router)

© 2005 Cisco Systems, Inc. All rights reserved. CIT v An Example of a Network Configuration Table (Switch) Catalyst Name, Model, Management IP Address Port NameSpeed STP State (Fwd or Block) Trunk StatusDuplex PortFast (Yes or No) Ether- Channel (L2 or L3) VLANs Burlington, WS- C SMI, /27 fa0/1 fa0/2 fa0/3 fa0/4 fa0/5 fa0/6 fa0/ A-100 Full Half A-Full Fwd Block Fwd No Yes No On Off On L

© 2005 Cisco Systems, Inc. All rights reserved. CIT v The Components of a Network Topology Diagram

© 2005 Cisco Systems, Inc. All rights reserved. CIT v The Components of a Network Topology Diagram

© 2005 Cisco Systems, Inc. All rights reserved. CIT v The Components of a Network Topology Diagram

© 2005 Cisco Systems, Inc. All rights reserved. CIT v Topology Diagram Components Physical Layer Device Name Media Type Interface Name Speed Data Link Layer MAC Address VLANs EtherChannel Trunk STP Route Encapsulation Network Layer IP Address Subnet Mask Routing Protocol(s)

© 2005 Cisco Systems, Inc. All rights reserved. CIT v Network Topology Diagram (Example No. 1)

© 2005 Cisco Systems, Inc. All rights reserved. CIT v Network Topology Diagram (Example No. 2)

© 2005 Cisco Systems, Inc. All rights reserved. CIT v Choose a starting point and view the name and model of the device. Also view the version of the operating system that the device is running. 2 Determine active interfaces and their addresses. 3 View a summary of the interfaces on the device, including the IP address/subnet mask, interface name, media type, and physical and data link operational status. 4 View the MAC address for any interfaces or ports. Discovering Network Configurations on Routers and Multilayer Switches

© 2005 Cisco Systems, Inc. All rights reserved. CIT v View details about the spanning-tree status on the device. 7 View a list of Cisco devices that are directly connected to the device that you are requesting from. 8 View details about any connected device, such as its IP address and capabilities. 5 View a summary of the IP routing protocols enabled for the device. Discovering Network Configurations on Routers and Multilayer Switches (Cont.)

© 2005 Cisco Systems, Inc. All rights reserved. CIT v Discovering Network Configurations on Standard Switches 1 Choose a starting point and view the name and model of the device. Also view the version of the operating system that the device is running. 2 Determine active ports. 3 View a summary of the ports on the device, including port names, port status, duplex, and speed. 4 View a summary of the EtherChannel configuration on the device.

© 2005 Cisco Systems, Inc. All rights reserved. CIT v Discovering Network Configurations on Standard Switches (Cont.) 6 View details about the spanning-tree status on the device. 7 View a list of devices that are directly connected to the device from which you are requesting. 8 View details about any connected device, such as its IP address and capabilities. View a summary of the trunk status of any ports that are in trunking mode. 5

© 2005 Cisco Systems, Inc. All rights reserved. CIT v Creating Network Documentation

© 2005 Cisco Systems, Inc. All rights reserved. CIT v Guidelines for Creating Network Documentation Determine the scope.Know your objective.Be consistent.Keep the documents accessible. Maintain the documentation!

© 2005 Cisco Systems, Inc. All rights reserved. CIT v Summary The components of a network configuration table and topology diagram can be categorized by the logical layers that they are associated with in the TCP/IP networking model. The components of a topology diagram are usually a combination of the most important components of several logical layers. Following a procedure, a troubleshooter can easily gather relevant configuration information about routers and switches. Performing the five stages in the process of creating network documentation allows a troubleshooter to create a network configuration table and topology diagram. Guidelines for creating effective network documentation are as follows: –Determine the scope –Know your objectives –Be consistent –Keep the documents accessible –Maintain the documentation