30 / 30 / 30 Resets. Voodoo or real?

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thiggins

Mr. Easy
Staff member
This sure smells like an unnecessary urban myth. And performing it more than once, even more so. Where did this come from?
 

htismaqe

Very Senior Member
Not an urban legend but doesn't apply to all manufacturer's. Back in the Netgear WNDR3700v1 days, it was the only way to be sure the router was completely reset.
 

htismaqe

Very Senior Member
Not that I know of. Certainly doesn't work any better on the R7000 than just resetting it from within the GUI.
 

TonyH

Very Senior Member
Thanks. That's what I thought.

Originates from early days of router, WRT54G era and dd-wrt. It is a passe now. Today's routers don'tneed it. Now I press and hold down reset button for couple mins. for certain cases trouble-shooting.
 

mstombs

Very Senior Member
It is voodoo, and potentially forces the router to reboot multiple times BUT used to be effective because the reset button on routers is not a hard reset, it is handled by software, and a full reset would involve both running firmware and bootloader.

When the router is running, perhaps badly, the firmware may not respond instantly. Holding the button in and then connecting power is an attempt to get the bootloader (Broadcom CFE) to handle the reset button, unfortunately this doesn't always work because the GPIO pin connected to the reset button is often defined by an nvram parameter, so if the nvram is corrupt, no reset function.

It is possible Asus have hardcoded the reset_gpio in more recent CFEs, which improves chances of recovering from corrupt nvram with resorting to JTAG, see comment in an AC66u file

https://github.com/RMerl/asuswrt-me...m/bcm947xx/compressed/rt-ac66u_nvram.txt#L326

I have read through some other Asus CFE code (from earlier GPL release), when that detects the reset button pressed it then waits until button released before resetting nvram and continuing, so no benefit in holding for another 30 seconds once it has detected it, see here for example code

https://github.com/RMerl/asuswrt-me...ommon/board/bcm947xx/src/bcm947xx_devs.c#L116
 
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RMerlin

Asuswrt-Merlin dev
From what I gathered, 30/30/30 was an attempt at devising a single procedure that would work on a large number of routers (which was necessary with DD-WRT due to the large amount of supported models). Using this today is a bad idea, as it flat out won't work with certain models, leaving you with a router in recovery mode instead of with a cleared nvram.

Always best to go with the procedure documented by the router manufacturer.
 

sm00thpapa

Very Senior Member
I have loaded DD-WRT on many routers and this only works on older WRT54G versions from years ago. I also loaded DD-WRT on older Linksys routers with out doing this and got the same result DD-WRT ran fine.
 

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