The IBM 23L4173 is a PCI (Peripheral Component Interconnect) network adapter designed to provide reliable Ethernet connectivity at speeds up to 100 Mbps. This adapter card fits into a standard PCI slot on IBM-compatible servers and workstations, offering an instant upgrade or replacement for onboard network interfaces. It supports both 10 Mbps and 100 Mbps network speeds, auto-negotiating the optimal speed based on the network infrastructure. This flexibility ensures compatibility with a wide range of network environments, from legacy 10 Mbps networks to faster 100 Mbps systems. The adapter includes a variety of features aimed at improving network performance and reliability, including support for full and half-duplex operations, integrated MAC and PHY, and compliance with IEEE 802.3 standards. The IBM 23L4173 is engineered for easy installation and delivers stable, efficient Ethernet connectivity, making it a valuable component for businesses looking to maintain robust network connections.