1

The output of the netstat-i command on AIX 7.1 / AIX 7.2 :

Name  Mtu   Network     Address            Ipkts Ierrs    Opkts Oerrs  Coll
en0   65390 link#2      e2.f9.3a.a8.fc.2     1205     0       71     0     0
en0   65390 10.140.128  nix-aix71-vs02-v     1205     0       71     0     0
lo0   16896 link#1                            108     0      108     0     0
lo0   16896 127         localhost             108     0      108     0     0
lo0   16896 localhost                         108     0      108     0     0
  • Why there are duplicates of the interfaces in the output.? What is the significance of the them?
  • For ex: Why there are two en0 with different Network and different Address.?
  • Would the value for Ipkts, Ierrs, Opkts, Oerrs and Coll will always be same if the interface Name is same?
2

As far as I remember this is auto-generated name of network if you do not name explicitly this network. You can check in file /usr/samples/tcpip/networks for sample file about network naming in AIX.

Here is extract from AIX documentation (7.1): Description

The /etc/networks file contains information about the known networks that comprise the DARPA Internet. Each network is represented by a single line in the networks file. The format for the entries in the networks file is:

Name Number Aliases

The fields are described as follows: Item Description Name Specifies an official network name. Number Specifies a network number. Aliases Specifies any unofficial names used for the network.

Items on a line are separated by one or more spaces or tab characters. Comments begin with a # (pound sign). Routines that search the networks file do not interpret characters from the beginning of a comment to the end of that line. Network numbers are specified in dotted-decimal notation. A network name can contain any printable character except a field delimiter, new-line character, or comment character.

The networks file is normally created from the official network database maintained at the Network Information Center (NIC). The file can be modified locally to include unofficial aliases or unknown networks.This file is part of TCP/IP in Network Support Facilities.

Edit: So they are the same interface, the same route, the same network

1

en0   65390 link#2      e2.f9.3a.a8.fc.2     1205     0       71     0     0

and 2

en0   65390 10.140.128  nix-aix71-vs02-v     1205     0       71     0     0
  • Thanks Romeo for the answer, But I am still a beginner at Network and Interfaces, so I couldn't summarise anything from your reply. Can you tell if this is correct inference : 1) One en0 is the alias of the other. 2) Both the en0 gives same output for Ipkts, Opkts,etc. – Jay Joshi Apr 24 '18 at 8:43
  • 1
    @JayJoshi, What mean is 1st line is with resolve the network name, 2nd w/o resolve the network name. So they are the same interface, the same route, the same network – Romeo Ninov Apr 24 '18 at 8:46
  • Actually they are technically not the same, one is the regular IPv4 address you are probably using, and the other is the automatically generated link-local IPv6 address. – doktor5000 May 4 '18 at 6:11

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