8.2.6. Other Interfaces

Other common interface configuration files include the following:
  • ifcfg-lo — A local loopback interface is often used in testing, as well as being used in a variety of applications that require an IP address pointing back to the same system. Any data sent to the loopback device is immediately returned to the host's network layer.


    Never edit the loopback interface script, /etc/sysconfig/network-scripts/ifcfg-lo, manually. Doing so can prevent the system from operating correctly.
  • ifcfg-irlan0 — An infrared interface allows information between devices, such as a laptop and a printer, to flow over an infrared link. This works in a similar way to an Ethernet device except that it commonly occurs over a peer-to-peer connection.
  • ifcfg-plip0 — A Parallel Line Interface Protocol (PLIP) connection works much the same way as an Ethernet device, except that it utilizes a parallel port.
  • ifcfg-tr0Token Ring topologies are not as common on Local Area Networks (LANs) as they once were, having been eclipsed by Ethernet.