GL-AR750S - demistifying ifconfig output


#1

Hi,
just got a GL-AR750S and am trying to understand what I’m seeing with ifconfig and how it relates to how the device physically looks like.

Physically the device has:

  • wifi 2.4G
  • wifi 5G
  • WAN ethernet port (1st in direction left->right)
  • LAN ethernet port (2nd in direction left->right)
  • LAN ethernet port (3rd in direction left->right)

A compressed view of ifconfig -a and brctl show (some interfaces were skipped) :

br-lan
    * bringing eth0.1, wlan0 and wlan1. Conceptually that is a switch with 3 ports.  
    * the bridge itself [has an IP address](https://unix.stackexchange.com/questions/319979/why-assign-mac-and-ip-addresses-on-bridge-interface) (192.168.8.1) serving as the web UI
eth0
    * A normal Ethernet interface
    * Not clear how does it relate to the two physical Ethernet ports and what can one do with it?
eth0.1
    * A VLAN interface
    * Not clear how does it relate to the two physical Ethernet ports?
eth0.2
    * Another VLAN interface
    * This seems to be tied physically to the  WAN port. It has an external IP when it's connected to a gateway
    * Due to being in a separated VLAN this is only accessible via routing
wlan0, wlan1
    * guessing these represent access points for the 2.4G and 5G wifi's
teql0
    * don't know what this is

This is as far as I got.
If someone can fill up the unknowns or correct what’s wrong, please feel free to :slight_smile:


#2

eth0 is the CPU port, while eth0.1 and eth0.2 is the vlan interface which based on eth0.

eth0.2 bind with port 2(wan), and eth0.1 bind with port 0 and port 1(two lan).

Please refer to https://openwrt.org/docs/guide-user/network/vlan/switch for more details.

teql0 is a virtual network interfaces, which facilitates a queuing approach via the tc (traffic control) tool.