[mythtv-users] Mythbackend not binding IPv6 ULA

[Hika van den Hoven]

Hoi Rob,

Wednesday, November 26, 2014, 5:45:43 PM, you wrote:


> On Tuesday, November 25, 2014, Hika van den Hoven <hikavdh at gmail.com> wrote:


> I think the issue here is more simple. He at first had put his
> hostname in and got his public ip-address. I guess he has no local dns
> and the address was provided by his providers dns, who off cause could
> not have any knowledge of his local addresses.


> The hostnames are resolving across the network.  When I ping the
> machines from different devices, they resolve to their only ipv4
> address for the appropriate interfaces and their global ipv6 address
> for the same interface.  The pings make their way to the right interface and MAC address.
> The challenge with Myth is that it's applying it's own firewalling
> by listening for specific addresses. My understanding was that the
> purpose historically has been differentiating between
> link-local/loopback vs public and this can make sense when you want
> to limit the interfaces that the program uses, but this is still
> essentially acting more as a firewall than anything else. This
> worked under ipv4 where each interface used one address, but breaks
> in the ipv6 worked where each interface can have multiple addresses.
> Another quirkis that while I'm able to tell Myth to listen for
> calls to its hostname under the ipv4 address selection, no such
> option is available for the ipv6 field.  If this were available
> under  the ipv6 field, the problem should go away because the
> resolution will get updated each time my ISP signs me a new prefix.
> Perhaps I can try manually overriding this in MySQL, but that test
> will have to wait until I finish moving and can unpack all of my belongings again.

I haven't yet really worked with ipv6. As yet I haven't seen the use
on my 10-15 device local network and I have a hard ipv4 internet
address and a proper linux router.
That said, I understand that you have on every machine two ipv6
addresses, ULA and global, this I guess to make NAT unneeded. For any
resolving mechanism to know to distinguish between them I guess you
also need two domainnames, local and global. Obviously if no
domainname is supplied it chooses global. As your ping test shows.
I use on my (ipv4) network my own 'fantasy' domainname (home.dkw).
This is obviously not usable on internet, but it doesn't need to. My
local DNS (a full bind dns, for provider DNS's can be unreliable)
knows it and uses it as the default if omitted.  
That Mythtv uses only the ULA is only more save in matters of unwanted
exposure to the public internet.

I don't know what resolving mechanism you use. But you have to look
there. To find how it distinguishes between ULA and global.

Tot mails,
  Hika                            mailto:hikavdh at gmail.com

"Zonder hoop kun je niet leven
Zonder leven is er geen hoop
Het eeuwige dilemma
Zeker als je hoop moet vernietigen om te kunnen overleven!"

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