troubleshooting

7 Windows & Cisco commands for network troubleshooting

To Troubleshoot Cisco and Windows networks, you need to know command equivalents. Cisco and Windows commands are similar but not identical.

Here are 7 Windows and Cisco commands that you should know:

1. ping- used both in Windows and in the Cisco IOS to verify connectivity from of to a router (default gateway) and from a router to a PC.
2. traceroute or trace in the Cisco IOS or tracert in Windows - used to trace the path your network traffic takes to a destination (like the web server you are trying to access) or from your router to a downstream router.
3. arp -a in Windows or show ip arp in the Cisco IOS - used to verify Layer 2 to Layer 3 mappings (aka Ethernet to TCP/IP) or Ethernet MAC Address to IP Address (and vice versa).
4. ipconfig /all in Windows or show ip interface brief in the Cisco IOS - used to show the IP address configuration for your NIC on your PC or for your router’s LAN/WAN interfaces. This output would include the IP Address, Subnet Mask, Default Gateway, and (on a PC), even the DNS Servers.

These are all pretty basic commands but they are all necessary commands that you must know to troubleshoot Windows and Cisco Networking.

Happy Troubleshooting!

What is CDP and how can it help you?

he Cisco Discovery Protocol (CDP) is a proprietary layer 2 management protocol for networks. CDP provides network device inventory, connectivity information, and IP next hop info. It works on LANs and WANs. CDP also works no matter the layer 3 network in use. This, no matter if you are running TCP/IP, Decnet, or Novell IPX- CDP will still function and provide the same info. CDP is excellent for troubleshooting.

I have used CDP to find out what the IP address is of a misconfigured router or switch on the other side of a WAN link. CDP can be enabled/disabled at the interfae level or globally on the whole router/switch.

Here are 6 CDP commands you should know:

1. cdp run and cdp no run - to enable and disable CDP globally
2. cdp enable and no cdp enable - to enable and disable cdp per interface
3. show cdp neighbors - to view see what routers and switches are connected to you on the LAN or WAN.
4. show cdp interfaces - to see which of your interfaces are participating in the CDP exchange
5. show cdp entry - to look at a particular switch or router that is a neighbor
6. show traffic - to see statistics about how many CDP packets have been exchanged

Also, you can also set cdp timers and clear cdp statistics.

For more information on CDP see the Cisco IOS Configuration Fundamentals Configuration Guide, Configuring Cisco Discovery Protocol (CDP) section.