AIX networking basics: lsdev -Cc adapter, en/et interfaces, smitty tcpip, and netsvc.conf

Goal

Identify the network adapters on an AIX LPAR, configure or inspect a TCP/IP interface the AIX way, and control host-name resolution order predictably.

Prerequisites

Root access; console access through the HMC (vtmenu or the virtual terminal) before changing the interface your session runs over, because a wrong address or route cuts the connection; know whether the target interface is virtual (VIO/SEA-backed) or a physical adapter, since some diagnostics differ.

Steps

1. List installed adapters: lsdev -Cc adapter shows every adapter object AIX knows about (Ethernet, Fibre Channel, SAS, and so on) with its current state (Available or Defined).
2. Map an adapter to its interface: for each Ethernet adapter entN, AIX can present an enN (Standard Ethernet Network Interface) or an etN (IEEE 802.3 Ethernet Network Interface) logical interface; most environments use the en interfaces.
3. Configure interactively with SMIT rather than editing files directly: smitty tcpip opens the TCP/IP menu (Minimum Configuration & Startup, Further Configuration, Name Resolution, and more); the "Minimum Configuration & Startup" path is effectively mktcpip, which sets the hostname, interface, IP address and default gateway together and stores them in the ODM so they persist.
4. For an already-running interface, ifconfig <enN> shows or sets the address/netmask at runtime, but a change made only with ifconfig does not persist across reboot; persisting an interface's configuration is a chdev operation against the interface object (for example chdev -l en0 -a netaddr=<ip> -a netmask=<mask>, which also applies it immediately) or the mktcpip/SMIT path, not an ifconfig flag. Record the current values with lsattr -El en0 first so they can be restored.
5. Set name-resolution order deliberately rather than relying on the compiled-in default (BIND/DNS, then NIS if running, then /etc/hosts): create /etc/netsvc.conf with a line such as hosts=local,bind4 to check /etc/hosts before DNS, or override per-session with the NSORDER environment variable, for example NSORDER=local,bind4.
6. Verify: lsdev -Cc adapter, ifconfig <interface> and lsattr -El <interface> for runtime and stored state; NSORDER overrides /etc/netsvc.conf, so check that echo $NSORDER prints nothing before testing a lookup that should follow the file.

Expected result

Adapters and their logical interfaces are correctly identified before configuration; the chosen interface configuration survives a reboot because it was set through chdev/mktcpip/SMIT rather than ifconfig alone; name resolution follows the intended, explicit order.

Limits and test basis

This covers the "classic" AIX TCP/IP model (LPAR with en/et interfaces and SRC-managed inetd/named); Shared Ethernet Adapter and VIOS-side configuration are managed from the VIO server, not from the client LPAR, and are out of scope here.