[TriLUG] Router issues

[Igor Partola]

TriLUG,

I am having some trouble with a router and I am wondering if others have
experienced something similar in the past or can point me in the right
direction for resolving. Here's my setup:

ASUS RT-N66U running TomatoUSB (1.28.0000 MIPSR2-095 K26 USB Mega-VPN), set
up with Optware. The only Optware actually running on the router is an
instance of bind9 with a small local set of DNS entries. This instance is
set up to then resolve any other requests recursively.

The router is connected to a Gigabit switch for the local wired network and
provides two wireless networks (one on the 2.4GHz band and another on the
5GHz band).

There are about 15 wired computers, about a dozen wireless devices
(laptops, phones) and 4 or 5 wired VOIP devices from RingCentral.

The problem I see is that several times a day the router stops working.
These bouts last about 2-3 minutes during which the router responds to only
about 1 out of 10-20 pings. Any other host on the network is perfectly
responsive during this time.

After the issue resolves itself, I can ssh to the router and see that it
had no spike in CPU usage, is not out of memory and there was no bandwidth
spike during this time.

So far, the only thing I was able to do is try resetting the router which
does fix the issue once it is back up. However, this is not an acceptable
long term solution so I am looking for a way to debug the issue.

Any theoretical help or practical pointers on how to debug this (short of
JTAG debugging) would be very much appreciated.

Thanks,
Igor