A Tip Regarding Modems Spontaneously Rebooting

https://plus.google.com/+LaurenWeinstein/posts/6C6k85GXgTQ

It's too early to be really definitive about this, but I thought I'd
pass it along anyway now for whatever it's worth. The ISP modem on one
of my data circuits started spontaneously rebooting recently, on
average about once a day (or more frequently). Because it takes at
least five minutes to come fully back up, this disrupts public facing
services. 

My logs suggested that this behavior began sometime after the
associated ISP boosted the upstream speed on that circuit. Even
leaving aside summer heat issues (which are very real) I started
wondering what could be triggering those reboots. A possibility based
on my research was that processor overloading of some sort was
involved, or perhaps internal tables overflowing. This modem routes in
a slew of static IPs, so it presents a fairly wide attack surface for
port scanners and the like. 

Digging deep in the internal modem configurations, I found a bunch of
default enabled so-called "attack protection" settings -- for
categories like packet floods, port scans, and others including a
vaguely labeled and undocumented "misc" category. On the assumption
that these were perhaps eating significant resources given the numbers
of addresses and ports involved, I disabled them all -- knowing that
my immediately downstream router was more than capable of handling
such issues. 

So far -- and it's been several days now, the unit hasn't rebooted. It
could be a coincidence -- or not. Time will tell. I know a lot of
people experience modem rebooting issues -- perhaps this will help
some of them.

--Lauren--
Lauren Weinstein ([email protected]): https://www.vortex.com/lauren 
Lauren's Blog: https://lauren.vortex.com
Google Issues Mailing List: https://vortex.com/google-issues
Founder: Network Neutrality Squad: https://www.nnsquad.org 
         PRIVACY Forum: https://www.vortex.com/privacy-info
Co-Founder: People For Internet Responsibility: https://www.pfir.org/pfir-info
Member: ACM Committee on Computers and Public Policy
Google+: https://google.com/+LaurenWeinstein
Twitter: https://twitter.com/laurenweinstein
Tel: +1 (818) 225-2800
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