100G has moved out of the data center and into the distribution switch down the hall, but most enterprise teams have nothing that can test it. It also doesn’t behave like a faster 10G: links can look healthy right up until they fail. NetAlly VP of Product Thomas Doumas introduces the LinkRunner 100G, a handheld tester that brings high-speed Ethernet testing to enterprise teams. Doumas, who helped create the original LinkRunner at Fluke Networks in 2000, presented the product to delegates at Networking Field Day 41.

Doumas explained that 100G interleaves four 25G lanes. On short-reach multimode fiber those lanes are separate fibers, and on single-mode they are separate wavelengths. Raw links run at a bit error rate near 10^-5, and forward error correction brings that to the roughly 10^-14 Ethernet needs. Both ends must use the same FEC scheme, and nothing auto-negotiates speed, FEC, or lane layout, which leaves about 30 ways a port might link. FEC also hides slow degradation. One London customer paired a long-range optic with a short-range one, and the overdriven receiver eventually overheated and failed weeks later. The LinkRunner 100G works with the customer’s own transceivers. Its QSFP28 Insights app reads module memory, tries every possible link mode, catches double-FEC configurations, and exposes breakout ports. Auto-test then works up the stack to flag rogue DHCP servers and trace switch paths, and a pair of units runs bidirectional Y.1564 performance tests at up to 100G.

Doumas framed the tool as a replacement for workarounds that fall short. Servers can’t push 100G for iperf. Laptop-and-media-converter setups rely on guesswork. Optical testers from EXFO or VIAVI cost $25,000 to $75,000 and characterize glass rather than networks. Teams also stop “swapping their way to success” and filling boneyards with $3,000 transceivers that may be perfectly fine. Through the LinkLive cloud service, an on-site technician can plug the unit in while a remote engineer runs it. Doumas acknowledged gaps when delegates asked: this model has no packet capture and no RoCEv2 visibility, and he said NetAlly wants to learn more about those needs. His strongest case was financial. A Seattle beta customer replaced a $30,000-per-month 100G wavelength service with $3,000-per-month dark fiber that it turned up itself, saving $27,000 every month.

Presented by Thomas Doumas, VP of Product. Recorded live at Networking Field Day 41 in Santa Clara, CA on October 6, 2026. Watch the entire presentation at https://techfieldday.com/appearance/netally-presents-at-networking-field-day-41/ or visit https://techfieldday.com/event/nfd41/ or https://NetAlly.com/ for more information.