11 Linux® Utilities Summary

This section describes the Linux utility tools that are used to perform control and status operations. There are three commonly used utilities in Ethernet interface debugging: ifconfig, ip, and ethtool. The following are brief descriptions about each utility.

• ifconfig - Provides basic information regarding the interface. The output provides a summary of the current state of the interface. The following example shows that the interface is up and has an IP address (192.168.1.5). There are also counters for the number of RX and TX packets. The example given here shows a normal working interface. The ifconfig utility only gives statistics on a higher networking layer than ethtool, which gives the data-link layer results. Additionally, ifconfig is not as up to date as the ip utility tool.

root@am62xx-evm:~# ifconfig eth0
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.5  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::1e63:49ff:fe1f:d9b2  prefixlen 64  scopeid 0x20<link>
        ether 1c:63:49:1f:d9:b2  txqueuelen 1000  (Ethernet)
        RX packets 552490  bytes 61792471 (58.9 MiB)
        RX errors 0  dropped 6  overruns 0  frame 0
        TX packets 646  bytes 50358 (49.1 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

• ip - Networking tool for controlling and interrogating the network interfaces. The ip utility is more versatile than the ifconfig utility.
  • The following example shows how to list the IP address for the eth0 interface.

    root@am62xx-evm:~# ip addr show dev eth0
    2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
        link/ether 1c:63:49:1f:d9:b2 brd ff:ff:ff:ff:ff:ff
        inet 192.168.1.5/24 metric 1024 brd 192.168.1.255 scope global dynamic eth0
           valid_lft 73177sec preferred_lft 73177sec
        inet6 fe80::1e63:49ff:fe1f:d9b2/64 scope link
           valid_lft forever preferred_lft forever

  • The following example shows how to statically set an IP address with the ip utility. This is used in a direct connect topology when there is not a DHCP server present.

    root@am62xxsip-evm:~# ip addr add 192.16.1.1/24 dev eth0
    root@am62xxsip-evm:~# 
    root@am62xxsip-evm:~# ip addr show dev eth0
    2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
        link/ether 08:04:b4:32:5d:ce brd ff:ff:ff:ff:ff:ff
        inet 192.16.1.1/24 scope global eth0
           valid_lft forever preferred_lft forever
        inet6 fe80::a04:b4ff:fe32:5dce/64 scope link 
           valid_lft forever preferred_lft forever

  • The following example shows how to check the RX and TX counters with the ip utility.

    root@am64xx-evm:~# ip -s link     
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen0
        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
        RX:  bytes packets errors dropped  missed   mcast           
              9246      99      0       0       0       0 
        TX:  bytes packets errors dropped carrier collsns           
              9246      99      0       0       0       0 
    2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default ql0
        link/ether 1c:63:49:1a:da:62 brd ff:ff:ff:ff:ff:ff
        RX:  bytes packets errors dropped  missed   mcast           
             19654      61      0       0       0       0 
        TX:  bytes packets errors dropped carrier collsns           
             22919      88      0       0       0       0 
    ...

• ethtool - Provides a method for displaying and modifying the parameters of the Ethernet interface and accompanying device driver. There are several options for running ethtool. Two of the most commonly used are for examining the link status and the MAC hardware statistics. The specific options for these are given as examples throughout this application note.