Tools for Network Configuration and Maintenance

Network troubleshooting is one of the most challenging tasks you need to perform. You must fix problems involving your own computer, as well as how it interacts with computers around the world. Luckily, you have several tools at your disposal to find the information you need:

1. ping,
2. netstat,
3. arp, and
4. ifconfig.

The ping command checks network connections between computers by sending small test packets of information to a remote host. The "pinged" computer returns a copy of the test message to check for accuracy. For example, a modem connection with a noisy line will cause information loss that will be reported by ping. Use the ping command when you need to check the existence and integrity of a network connection.

netstat displays information about every TCP/IP interface on your computer. It can also display your routing table and interface statistics. When you need detailed information on your computer's interface(s) to the network, use netstat.

The Address Resolution Protocol (ARP)^[1] determines which host's network interface is assigned to an IP address, and allows your network's hardware to properly format data for the destination network device. The arp command displays and modifies these associations. You will use it to track down IP-to-Ethernet mapping problems.

ifconfig displays and modifies interface parameters such as IP address and netmask. When you find you need to modify interface parameters, use ifconfig.

In the next lesson, you will learn how to manage network interfaces with ifup/ifdown.
Before moving on to the next lesson, click the Exercise link below to practice matching configuration and connection tools with their functions.
Redhat Utilities Functions

[1] ARP: The Address Resolution Protocol. ARP is the method Ethernet computers use to assign IP addresses to Ethernet card addresses.