[mythtv-users] HDHR failing

Stephen Worthington stephen_agent at jsw.gen.nz
Sun Nov 15 03:17:02 UTC 2020

On Sun, 15 Nov 2020 10:09:57 +0800, you wrote:

>> On 15 Nov 2020, at 7:49 am, DryHeat122 <dryheat122 at gmail.com> wrote:
>> what I'd do is this
>> Other devices work.
>> Run other SW on your myth box. I can't recall what I used, I definitely used something, maybe a browser, maybe VLC.
>> If that works you have a myth problem, if it works not you have a conectivity issue.
>> None of that worked.  What did work is that I noticed that (I guess after the modem reset) the HDHR got assigned, whereas when I installed it in myth setup the address was  So I set up a static IP for the HDHR with that address, and voila!  It works with myth.  So somehow it myth was not detecting the new dynamic IP on reboot as I think it's supposed to do.  Maybe the tshark output I sent Stephen will offer some clues.  
>Unless there is something I’ve not understood then myth will NOT auto-config the IP of the tuners.
>DHCP is really useful but for myth you really want to have fixed IPs. The mess in the DB of a frontend that over years (for whatever reason) gets new IPs, each time you get a new IP you get an entry for that host, effectivly a new frontend, and loose any settings that you have configured for the ‘last frontend'

It is not as bad as that.  The frontend settings are stored under a
hostname in the database, not an IP address.  Changing the IP address
does not change the hostname, so you still get the same frontend
settings.  Only if you move a frontend to a different box with a
different hostname will it get different settings.  And you can get it
to keep on using the same settings even then by putting the old
hostname in the LocalHostName field in your config.xml file.

But you are right that if you put an IP address in the tuner settings
for the HDHR, and the DHCP assignment for the HDHR changes the
address, then the tuner will be unable to be found.  But I thought
that was fixed by not using IP addresses for HDHRs and instead
identifying them using their device ID, which does not change when the
IP address changes.  If the device ID is used, MythTV should be doing
a broadcast messsage with that ID and asking the HDHR matching that ID
to reply.  That is how I understand the "hdhomerun_config discover"
command works - it broadcasts a message for all HDHRs to reply and
picks up their device IDs from the replies.  After that, you can use
the device ID to connect to each HDHR individually.

So I think that it is a bad idea to use IP addresses in the MythTV
database for HDHR tuners unless you have set the HDHRs up with
manually assigned IP addresses in the DHCP settings, so the IP
addresses can not change.  Personally, I prefer to do manual DHCP
address assignments for all the devices that I have on my network, so
that when I am using tshark or Wireshark to look at network packets, I
can tell exactly where they are coming from.  And I also run my own
DNS server, so making sure the IP addresses can not change means I can
also have DNS names for all the devices, and tshark and Wireshark can
then display the names instead of IP addresses.

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