The ISP further questioned the validity of connecting a switch to its equipment. It had doubts as to whether the settings could be configured correctly on the LAN equipment. Since these options were available in the equipment's operating system, I assumed that the features worked per the standards.

It was about this time that I began to think about what the standards clearly said. The ISP was inferring that the problem was on the LAN side, and the LAN equipment manufacturer indicated the switch can in fact be set to operate with auto-negotiation disabled. It was time to hit the standards.

Clause 37

Everything Ethernet is covered under IEEE 802.3. Specifically, 802.3z covers Gigabit Ethernet auto-negotiation. Referenced as Clause 37 in 802.3, it states that auto-negotiation should be enabled on 1000BASE-X links.

"Should" does not mean "must," so at this point I turned to searching for interpretation of the standards. I didn't find much, but the few white papers I found suggested that auto-negotiation should not be enabled on any Gigabit Ethernet connection, regardless of media. In particular, I found an excellent paper by Sun Microsystems regarding best practices for Gigabit Ethernet auto-negotiation.