Eric on 15 Nov 2008 06:06:33 -0800


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[PLUG] network hardware follies


I'm trying to reset a Linksys RTP300 that my wife obtained for me from 
Freecycle.  It is a Linux-powered VoIP router.  The history of the device is 
unknown but I would presume that it's a former Vonage unit.  That may be a 
totally bogus assumption, I'll admit, but where it came from is irrelevant IF I 
can get it to work.

To begin to hack the device I powered it up and held the reset button for about 
1 minute (later extended to 3 minutes.)  In all cases there is no response from 
the default address (192.168.15.1 on one of the LAN ports) after the unit was 
"reset".  This mirrors my experience with Linksys devices which appear to resist 
resetting with a tenacity usually attributed to pitbulls.

The power is there (14.4V) and the LED's light up appropriately.  I even opened 
the device and checked to be sure the reset switch actually had 0 volts across 
it when pressed (of course it did.)

The courses of action I can think of are:

1.  Use nmap to scan like crazy trying to find the ip address that the unit is 
using which I presume is in one of these ranges:
    192.168.0.0/16 (netmask of 255.255.0.0)
  OR
    10.0.0.0/8 (netmask of 255.0.0.0).

2.  Reset it as before but remove the power supply connection and short the 
power input leads for about 24 hours to be sure it's really really really 
powered off.  I tried this for 1 minute with no detectable result.

3.  Place the unit in a local trash receptacle with unusual force.

Following course #1 first:

I'd like to hook it directly to a pc running Kubuntu and run nmap.  Can I use a 
"crossover" Ethernet cable for that purpose?  I just happen to have one.  If I 
do that is the IP address even relevant as long as it goes out of the Ethernet port?

What kind of nmap scan would be the quickest and still be most likely detect the 
unit?  I tried a ping scan over the home network and it takes about 40 seconds 
to scan the 192.168.15.1/24 range.  At that rate the entire 192.168.1.1/16 range 
will be about 3 hours.  I'm trying not to think about the 10.0.0.0/8 range. 
Okay, okay... I thought about it: 728 hours or about 1 month.  I'd rather try #2 
or #3 first :-)

Ideas and suggestions are really welcome!  At this point I'm starting to run out 
of ideas and #3 is starting to look better and better :-(

Eric
-- 
#  Eric Lucas
#
#                "Oh, I have slipped the surly bond of earth
#                 And danced the skies on laughter-silvered wings...
#                                        -- John Gillespie Magee Jr
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