External Interface

Name

EXTERNAL -- Interface Type "EXTERNAL".

Description

The EXTERNAL interface type is intended for interfacing with Ethernet, WiFi and other things yet to be decided.

The name is a hang-over from XR16, where an external TSR program managed the interface with the NIC packet driver. The external interface was also used to interface with BPQ-compatible drivers. XR32 also used an external program, NdisXpkt, to provide the Ethernet connection.

XRPi doesn't need an external driver for Ethernet, but rather than confuse existing XR sysops by introducing a new interface type, the same configuration was used.

A typical Ethernet INTERFACE and PORT combination is shown below:

	INTERFACE=5
		ID=eth0
		TYPE=EXTERNAL
		PROTOCOL=ETHER
		MTU=1064
	ENDINTERFACE

	PORT=7
		ID=Ethernet Adaptor
		INTERFACENUM=5
		IPADDRESS=192.168.0.221
	ENDPORT

The interface and port numbers are for example only.

In the INTERFACE block, the ID directive specifies the device name, e.g. "eth0" for the first Ethernet adaptor or "wlan0" for wireless LAN adaptor. These names may vary from platform to platform, e.g. on MX-Linux the wireless lan adaptor could be named "eth1" not "wlan0".

The PROTOCOL directive specifies the hardware layer protocol for the interface. At present only ETHER (Ethernet) protocol is used on this type of interface.

In the PORT block, The ID directive specifies a human-readable brief description of the interface, e.g. "LAN Adaptor (192.168.0.221)".

The IPADDRESS directive specifies the IP address to be used on this interface. This overrides XRPi's "core" IPADDRESS for this port only. It must be different to the Raspberry Pi's IP address, and must be appropriate for the local subnet.

Caveats

If XRPi is run from an account with root priviliges, no special conditions apply, otherwise its access to resources is restricted by Linux's security policies.

To use the EXTERNAL interface without root priviliges , the "xrpi" executable needs to be granted CAP_NET_RAW capability. See Capabilities for more information.

See also

IFACES -- Interfaces.
PORTS -- Ports.
CAPS -- Capability Flags.
RUNROOT -- Running XRPi as "root".
XROUTER.CFG(8) -- Main Configuration File.