ifconfig command

Edit online

The ifconfig command is the network interface configuration tool that allows the network interface STRUCTURE to be dynamically created or deleted from the kernel memory.

This command accepts data from the command line, then builds a memory structure that conforms to the parameters. For debugging purposes, the ifconfig command is used to examine the status of a communications interface.

Note: Any changes made to the attributes of an interface using the ifconfig command will be lost when the system is rebooted.

For example, to examine the current status of the sl1 interface:

  1. Enter the netstat -i command and examine the output selecting the appropriate sl# interface. For example, sl0, sl1, sl2, and so on.
  2. Enter the ifconfig sl# command and examine the ifconfig output for the following key fields:
    Item Description
    POINTTOPOINT flag This flag should always be present on an operational SLIP link. If not, the link could be in a down or disconnected state. Try issuing the ifconfig sl# up and the ifconfig sl# commands again to see if its condition changes.
    UP flag Indicates that the network sl# interface is activated and should be operational.
    RUNNING flag Indicates that the slattach command was successful. In actuality, the link is accessed, a dial is completed, the other end has answered, and the remote end has returned CARRIER DETECT status. When the CD status occurs the flags are updated with the running bit.