[mythtv-users] HDHomeRun, 2nd NIC and dhcpd bootup issue

William Munson william_munson at bellsouth.net
Sun Nov 4 10:24:37 UTC 2007

R wrote:
> I'm a long time user of MythTV and very much appreciate all the hard work everyone puts into the software. I recently decided I wanted a second HD tuner for OTA broadcasts and since I am already using 4 of 5 PCI slots, I decided to try a HDHomeRun. 
> While setting it up, I determined that the HDHomeRun used DHCP to get an IP address so I first connected it to my home network so my router would provide the IP address. My MythTV server is connected to my home network via a PCI Gigabit Ethernet card (eth0). Once everything was up and running, I wanted to move the HDHomeRun off my home network. I enabled the motherboard's 10/100 Ethernet NIC (eth1) and configured dhcpd to provide an address to it. After directly connecting the HDHomeRun to eth1 and restarting mythbackend, the tuners were available and working without any other changes. 
> Everything was great until my system was rebooted. 
> Turns out that after the reboot mythbackend reported "device not found" for both HDHomeRun tuners. After manually restarting mythbackend, the tuners were back and working. Thinking that the problem might be related to the second NIC and DHCP, I reconnected the HDHomeRun to my home network, rebooted and found that indeed, the tuners were discovered after the server restart.
> When facing an issue such as this, I figure I'm not the first to experience it and search the internet for a solution. This time, I couldn't find a solution. 
> Thinking that it might be a timing issue where the HDHomeRun did not yet have an address from my MythTV dhcpd server for the second NIC, I hunted in the code until I found the FindDevice function in libs/libmythtv/hdhrchannel.cpp. I noticed that it tries to "Discover" the HDHomeRun 6 times before reporting "device not found". I modified it to try 60 times to give the HDHomeRun a bit more time to get an IP address. After building and installing the change, I rebooted and found that the HDHomeRun was found by mythbackend after the server restart and my problem was solved.
> I don't know if the problem is unique to my configuration but, if not, perhaps my experience will help someone else.
> Richard
First off, this is not the only solution. What I ended up doing was to 
install a small 4 port switch between the myth system and the rest of 
the home network. This switch only has 3 connections. The myth system, 
the hdhr and a cable to the rest of the system. This keeps hdhr traffic 
local to that switch and allows my primary dhcp server to assign 
addresses. This provides plenty of bandwidth, especially if you run 
gigabit rather than 100/t. I run 100/t here and have no problems with 
being able to record 2 shows while playing another on a remote frontend.

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