8.3. Understanding the Predictable Network Interface Device Names

The names have two character prefixes based on the type of interface:
  1. en for Ethernet,
  2. wl for wireless LAN (WLAN),
  3. ww for wireless wide area network (WWAN).
The names have the following types:

Table 8.1. Device Name Types

FormatDescription
o<index>on-board device index number
s<slot>[f<function>][d<dev_id>]hotplug slot index number
x<MAC>MAC address
p<bus>s<slot>[f<function>][d<dev_id>]PCI geographical location
p<bus>s<slot>[f<function>][u<port>][..][c<config>][i<interface>]USB port number chain
  • All multi-function PCI devices will carry the [f<function>] number in the device name, including the function 0 device.
  • For USB devices the full chain of port numbers of hubs is composed. If the name gets longer than the maximum number of 15 characters, the name is not exported.
  • The USB configuration descriptors == 1 and USB interface descriptors == 0 values are suppressed (configuration == 1 and interface == 0 are the default values if only one USB configuration or interface exists).