The intended objective of this article is to provide designers with the basic knowledge to implement an Ethernet long-reach 40 Gb/s and 100 Gb/s host board. Ethernet was originated in the early 70s and has successfully displaced other popular communication standards, such as Token- Ring, becoming the default standard for local area networks in the enterprise office and datacenter equipment. Its success has roots on its basic open architecture and asynchronous protocol. During the lifetime of the Ethernet, the data rates have dramatically increased from its original 10 Mb/s to 100 Gb/s at the present time and the standard body is in the process of generating the next higher speed project most likely to be 400 Gb/s. In 2010 the IEEE802.3 body published the Ethernet 40 Gb/s and 100 Gb/s standard targeting the support of the next generation of communication equipment and components. The IEEE802.3ba™- 2010 Ethernet standard was a quantum leap to penetrate Communication Metropolitan applications, a.k.a. Wide Area Network (WAN), which were clearly dominated by the SONET/SDH protocol. This article is a continuation to the article published in the IEEE Communication Magazine in its April 2012 edition "40 Gb/s and 100 Gb/s Ethernet Short-Reach Optical and Copper Host Board Channel Design", which presented the challenges of designing 40 Gb/s and 100 Gb/s Ethernet host board electrical and optical channels targeted for Enterprise/Datacenter applications. The article reviews the long-reach for 40 Gb/s and 100 Gb/s Ethernet and the extendedreach Ethernet for 100 Gb/s host board channel electrical and optical specifications for Metropolitan/ Carrier applications. The long- and extendedreach links are intended for communication carrier equipment in inter- and intra-city infrastructures. The host board channel comprises the electrical (host board and connector) and the optical (module) sections. This article will analyze both sections and highlight the salient specificat- ons that the designer of 40 Gb/s and 100 Gb/s Ethernet switches and ports needs to know to comply with the standard.