[mythtv-users] HDHR failing

James Linder jam at tigger.ws
Sat Nov 14 02:36:44 UTC 2020

> On 14 Nov 2020, at 8:23 am, DryHeat122 <dryheat122 at gmail.com> wrote:
> It's kind of bizarre.  It was working fine with Myth, then stopped working.  This happened right after my cable modem required a restart.  I do have a firewall but it allows anything from the subnet.  The HDHR is on the same subnet.  I can ping it from the Myth box.  I don't think it's the power supply because I can access it from other devices, my Windows box, my Roku, another "smart" TV.  
> On Fri, Nov 13, 2020 at 3:07 AM David Watkins <watkinshome at gmail.com> wrote:
> Hi my input is general, not specific ...
> If other devices work the device is working.
> If you cannot see an ip ... then any of the following may apply 
> * The HDHR is not on the same network
> * Your backend has a firewall that prevents the HDHR being seen
> * Your backend has faulty network hardware
> * You have configured your HDHR to another network to your backend
> Start with ping and nmap. Post more info to help anyone who is trying to help.
> Your current post is "something is wrong somewhere. please help" <smile>
> ..or you could have a faulty Ethernet cable/connector or network switch.  To know how to troubleshoot this you need to understand your network a bit.
> How is your backend connected to the HDHR?  Wi-Fi or wired?  What other things are on the network?
> What IP address do the HDHR and mythbackend have, and how are they assigned?  They can be manually assigned or they can pick them up from a device running DHCP (usually either a wifi access point or your ISP's broadband modem/gateway).
> Once you (and we) understand your network then the troubleshooting can start.

Check that your mythbox AND hdpr have not been given an address that myth has not been configured to use.

IE before modem boot (say) mythbox and hdpr mythtv configured for
    after modem boot (say) mythbox        hdpr but mythtv configured for

as an aside, typically,

[the world]——[cable modem]=======[mythbox]======[hdpr]====== other devices
                nat              (say)

Then you do not need any firewall on mythbox
RFCs say no router on internet may route a private address (192.168.x.y, 10.x.y.z etc)
cable modem will send traffic to mythbox only for port forwards

So if mythbox has a private address you do not need a firewall
if mythbox does have a real ip then you do (and you can configure cable modem like this) 
the only reason to have cable modem enable a firewall is to stop infected (windoze) machines sending OUT naughty stuff.

If you are using cable-modem firewall it will have no effect on myth
If you are using a firewall on mythbox then turn it off (that will make your troubleshooting one step easier


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