[GTALUG] DHCP "hidden feature" / "Easter Egg"

[Walter Dnes]

  This is what I get for TTFM (Trusting The Fine Manual). I did Google
and RTFM.  Page 6 of the PDF document at the manufacturer's website...
http://www.silicondust.com/hdhomerun/hdhomerun_tech.pdf lists the output
from a "get help" command ***FOR CURRENT MODELS***.  It includes,
amongst other items...

/sys/ipaddr dhcp|"<ip> <mask> <gw> <dns>"

  On my machine, "get help" produces...

Supported configuration options:
/ir/target <protocol>://<ip>:<port>
/lineup/location <countrycode>:<postcode>
/sys/copyright
/sys/debug
/sys/features
/sys/hwmodel
/sys/model
/sys/restart <resource>
/sys/version
/tuner<n>/channel <modulation>:<freq|ch>
/tuner<n>/channelmap <channelmap>
/tuner<n>/debug
/tuner<n>/filter "0x<nnnn>-0x<nnnn> [...]"
/tuner<n>/lockkey
/tuner<n>/program <program number>
/tuner<n>/streaminfo
/tuner<n>/status
/tuner<n>/target <ip>:<port>

  There is no mention of "/sys/ipaddr" ***ON MY MACHINE***.  I also
remember various people asking on the HDHomerun support forum years ago
about IP addresses, and hearing that this model did not have any other
addressing options.  One correction on the date of my machine.   See
https://www.youtube.com/watch?v=JXmi-6nVhCM which discusses the exact
same model I have.  I bought mine in 2010, but the reviewer notes that
it won some award at CES2008.  Consider it a 2008 model.

  Due to the documentation, and lack of mention of DHCP in "get help",
I assumed it wouldn't work.  However, just for ####s and giggles, I
enabled the DHCP server on my router, set the DHCP address pool to
192.168.123.241-to-192.168.123.247, and expanded my local LAN subnet
from a /29 to a /28 like so...

config_eth0="
192.168.123.251/28 broadcast 192.168.123.255"
routes_eth0="
default via 192.168.123.254 metric 20
192.168.123.240/28 via 192.168.123.254 metric 0"

  Notice the lack of a 'modules=( "!iproute2" )' line.  I installed the
latest firmware update from the manufacturer's website...
(hdhomerun_atsc_firmware_20141124.bin).  Lo and behold, it actually
works, coming up at 192.168.123.241.  This is notwithstanding the
documentation and "get help" output, which both say nothing about DHCP.
Maybe this was a feature that was backported into a firmware update.
Anyhow, I apologize for wasting peoples' time.

-- 
Walter Dnes <waltdnes at waltdnes.org>