05/11/2026
A colocation ticket landed recently. The customer could not reach either of their firewalls (their own equipment) and asked what we could do. The standard playbook is for one of our Data Center Technicians to crash-cart the device or offer the customer the use of our Spiders. Firewalls have no video output, so crash-cart was out. That left the Console port.
Every device in the data center, switch, firewall, router, and even some servers, has a Console port of some sort. It is the first way in. The port you use to configure a box fresh out of the crate, or to monitor its basic status when nothing else is working. And almost universally, it speaks RS-232. A standard published in 1960 that still sits underneath nearly everything in a modern data center. (Some newer gear has USB console ports, but they still support RS-232 underneath.)
RS-232 needs three wires to do its job: Ground, Transmit, Receive. They have to land on the right pins on both ends or the device stays silent. About 90% of the equipment we work with uses the Cisco pinout, which is what our Spider cables are wired for. This customer's firewalls did not. None of our cables would talk to them.
The fix was a custom dongle. Ten minutes with a pinout reference, a few minutes wiring it up, and the right signals were routing from our Spider into the customer's Console port. The connection came up and the customer could see what was happening on their gear again.
Never hurts to think outside the (very old) box. Sixty-six years on, and RS-232 is still how you talk to a device when the network can't.
CC: Chris Dunn
