Last Updated on May 14, 2023 by Dave Farquhar
If you’re messing around with routers, you’re going to come across the phrase 30-30-30 reset. Often without explanation. Here’s what this reset is and why it works.
A 30-30-30 reset is the technique of holding the reset button on a router for 30 seconds, unplugging the power at the 30 second mark while continuing to hold the button down, then plugging the power back in while holding the button an additional 30 seconds before releasing. It’s helpful on older routers, but on AC routers and newer, it’s not recommended.
Origins of the 30-30-30
The 30-30-30 reset originated on the venerable Linksys WRT54G router. Sometimes, when loading the DD-WRT firmware on it, the router malfunctioned. Holding the reset button for around 30 seconds loads the factory defaults, but didn’t always seem to clear the rest of the unit’s volatile and nonvolatile memory. Holding the button an additional period of time with the power unplugged discharges the unit. Restoring the power while continuing to hold the reset button loads the factory defaults again. For some reason, reloading the factory defaults with the rest of memory zeroed out helps solve some strange problems. I got into the habit of doing the 30-30-30 reset any time I loaded DD-WRT.
This technique originated on Linksys routers and moved to similar DD-WRT-capable routers, but similar concepts exist on other types of computer devices, like zapping the PRAM in older Macintoshes. In theory, the 30-30-30 reset works on any router. In practice, it worked well on routers that used a Broadcom or similar MIPS-based router chipset.
It doesn’t have to be a precise 30 seconds back-to-back-to-back. Counting one-one-thousand, two-one-thousand up to 30 is close enough. You don’t need a stopwatch and a world-class reaction time to use the 30-30-30 reset effectively.
Is the 30-30-30 reset safe to do?
If you’re in the habit of doing 30-30-30 resets to fix routers, be careful about doing it on newer routers that can do AC wireless and gigabit. The 30-30-30 reset can cause problems on newer routers, especially the ones based on ARM chipsets. It’s usually safe to do on a wireless-N or G router, but not on AC. If you don’t know for sure, do some web searches before performing a 30-30-30 reset on your router, so you don’t render it unable to boot.
If you’re not sure, just do a standard factory reset, holding down the reset button for 30 seconds. I’ve never known that to damage a router.
David Farquhar is a computer security professional, entrepreneur, and author. He started his career as a part-time computer technician in 1994, worked his way up to system administrator by 1997, and has specialized in vulnerability management since 2013. He invests in real estate on the side and his hobbies include O gauge trains, baseball cards, and retro computers and video games. A University of Missouri graduate, he holds CISSP and Security+ certifications. He lives in St. Louis with his family.