Casey Bralla on 15 Nov 2008 08:04:20 -0800

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Re: [PLUG] network hardware follies

On Saturday 15 November 2008 9:06:23 am Eric wrote:
> 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.

If it is the Lynksys, I assume the data on this page may be of big help.

> 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 ( 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.

That's an odd sounding default address.  My guess would be, or 

> 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:
> (netmask of
>   OR
> (netmask of

These sound like good ranges to search.

> 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.

I doubt if anything more than 60 seconds would be necessary.

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

I chuckled at this one.   Maybe this is why it was available on freecycle?

> 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?

Cross over would work for a direct connection.   It also might be good to go 
through a hub, just so you can see the blinky-blinky lights.

> 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 range.  At that rate the
> entire range will be about 3 hours.  I'm trying not to think
> about the range. Okay, okay... I thought about it: 728 hours or
> about 1 month.  I'd rather try #2 or #3 first :-)

I'd do the default nmap scan.  You want to look for port 80 (web pages), 
telnet, ssh, and probably some others that I can't think of.   The ping may 
not echo, even if you get the correct IP address, so I wouldn't trust a 
simple ping.   This may take time to run, but it's a rainy day anyway :)

> 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


Casey Bralla
Chief Nerd in Residence
The NerdWorld Organisation
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