The EIPR links two Internet Protocol (IPv4) networks together — passing appropriate traffic while blocking all other traffic. One of the networks is designated the local-area-network (LAN) and the other the wide-area-network (WAN). Because of the built-in stateful firewall, communication initiated on the LAN-side passes through the router while WAN-side initiated communication is blocked. With Port Address Translation (PAT), several clients on the LAN-side can gain access to the Internet. With Network Address Translation (NAT) there can be a one-to-one translation between LAN-side and WAN-side addresses. With Port Forwarding, servers on the LAN-side can be accessed from the Internet via the WAN-side port. The EIPR incorporates a four-port 10/100 Mbps Ethernet switch for multiple LAN-side connections. An external Ethernet-based modem — cable or DSL — attached to the 10/100 Mbps WAN-side port can be used to connect to the Internet. DSL modems connect via the PPPoE protocol.
Although the EIPR has many of the same features found in high-end routers, it is simpler to install and commission. A resident DHCP server on the LAN-side will provide IP addresses to LAN-side clients while a DHCP client on the WAN-side will accept IP address assignments from the attached modem. Static addressing is accommodated as well. Configuration is via a web browser using authentication. With a DIN-rail mounting clip, rugged metal enclosure and the ability to be powered from a low-voltage AC/DC power source, the EIPR is ideal IP router for automation systems.