Troubleshooting

1. Introduction

Network troubleshooting is the act of discovering and correcting problems with connectivity, performance, security, and other aspects of networks. It is a combination of measures and processes used to identify, diagnose and solve problems within a computer network. It’s a logical process that network engineers use to resolve network problems and improve network operations. Troubleshooting is an iterative process, the more data you collect and analyze, the higher the likelihood of developing a correct hypothesis.

2. Ping

Ping is a network administration software utility, used to test the reachability of a host on a network. It is available virtually for all systems that have networking capability. This command is used in privileged mode.

 Switch#ping 192.168.0.1

3. Trace-route

This command can detect the route of the data packets from one host to another host. If you want to achieve this functionality, you need to enter the target IP address.

 Switch#trace-route 192.168.0.1

4. Debugging

The debug ip packet commands are useful for analyzing the messages traveling between the local and remote hosts. IP debugging information includes packets received, generated, and forwarded. These commands are executed in the privileged mode.

Switch#debug ip all

The above command debugs all IP, ARP, ICMP, UDP, TCP and other protocol packets. It resolves the important field of IP header, including the protocol type, packet length, and layer four messages, such as port number.

For individual debugging of a specific protocol the following commands are used:

Switch#debug ip arp

Switch#debug ip icmp

Switch#debug ip recv

Switch#debug ip send

Switch#debug ip udp

Switch#debug ip tcp

The following command orders for the closure of the corresponding debug ip packet switching.

Switch#no debug ip all

The following command is used to check the current open debug command in the switch.

Switch#show debugging ip