Configuring Ethernet Interfaces

The AirLink router is equipped with one or more Ethernet ports (depending on the router model) that can be enabled or disabled as needed. When the port is disabled, the connected device cannot connect via Ethernet, and ARP queries do not receive responses on the port.

The AirLink XR90 has four Ethernet ports, labeled 1 to 3, with the fourth port reserved for RS-232 use, with two additional ports on the XP1 and XP2 cartridges. By default, all Ethernet ports are configured as LAN interfaces; however, it is possible to configure ports as WAN interfaces (see below).

Configuring an Ethernet interface

• ENABLE or disable the interface.
• WAN AUTO DETECT: When WAN AUTO DETECT is enabled (the default setting), the router attempts to determine if a DHCP server is present on the Ethernet network. If a DHCP server is found, the router obtains an IP address and enters WAN mode. If no DHCP server is found, the port is placed in the Default-LAN bridge.

When connecting the XR router to an internal network via Wi-Fi or Ethernet WAN, ensure that the network providing a WAN link does not use the XR router’s default internal subnet (192.168.1.0/24). The address conflict will prevent the WAN connection from being established.

For more information, see this Sierra Wireless Customer Community article.

When deploying the router, Sierra Wireless recommends that WAN AUTO DETECT be disabled, and that the Ethernet ports are manually configured for LAN or WAN.

• When WAN AUTO DETECT is disabled, you can configure the port for:
  • LAN mode by selecting a LAN segment (see LAN SEGMENT below)
  • WAN mode, by leaving the LAN segment field empty. When the port is in WAN mode, you can select the port’s IP assignment method (DHCP [default], static, or none) under Networking > General > WAN.

For applications where LAN-only clients are connected to an Ethernet port, Sierra Wireless recommends disabling WAN AUTO DETECT to ensure the fastest DHCP response times, if LAN DCHP server timeout responses are observed.

• LAN SEGMENT: When the interface is in LAN mode, you can select (or create) a LAN segment for the interface. Selecting a LAN segment is disabled when WAN AUTO DETECT is enabled; if a DHCP server is not found, the port is put into the Default-LAN by default

• MTU: When the interface is part of a LAN Zone, MTU is set to Auto. When in WAN mode, you can manually configure MTU if you have packet loss due to network fragmentation issues, and as directed by your service provider.
• LINK MODE: Configures the Ethernet port speed and duplex setting. Most of the time you can leave the default setting and the device you are connecting automatically negotiates the speed and duplex setting with the AirLink router. However, if the connected device has a fixed setting, use this field to change the AirLink router setting to match that of the connected device. You may need to lower link speed to reduce power consumption for applications where the router runs from battery power, or to be compatible with devices that do not support auto negotiation.

Confirming Ethernet port configuration

You can check your Ethernet port configuration under Status/Monitoring > Dashboard.

Under Hardware Interfaces > General > Configuration, you can:

• View a summary of the Ethernet interfaces
• Enable or disable each interface
• Add an Ethernet interface to a LAN bridge (if WAN AUTO DETECT is off for that interface).

You can configure an Ethernet interface for WAN mode by leaving the Bridge field empty.