The Comnet RLXE4GE24MODMS is a substation-rated and industrially hardened modular all-gigabit managed Layer 2 switch/Layer 3 router. It is designed for mission-critical environments where high levels of electromagnetic noise, interference (EMI), and severe voltage transients or surges are common, such as electrical utility substations, switchyards, heavy manufacturing facilities, and trackside electronic equipment. This switch/router offers Layer 3 static routing for establishing core network infrastructure while maintaining Layer 2 compatibility for flexible deployment. Its modular design includes four chassis slots that support a variety of module configurations with 10/100/1000BASE-TX and 100/1000BASE-X SFP* ports. The uplink module slot accommodates either a 1 Gbps or 10 Gbps module with two or four SFP+ ports, enabling high-capacity backhaul. Dual, user-replaceable redundant power supply modules ensure maximum reliability by eliminating single points of failure. The RLXE4GE24MODMS also supports multiple Ethernet redundancy protocols, including Comnet C-Ring (with recovery times of less than 30 ms and integration of more than 250 switches), as well as MSTP, RSTP, and STP. With its hardened design, modular scalability, and advanced redundancy features, the RLXE4GE24MODMS delivers high reliability and long-term adaptability for demanding substation, industrial, and transportation applications.