[avahi] Strange MDNS response from Axis cameras

Iván Sánchez Ortega i.sanchez at mirame.net
Wed Feb 15 08:49:24 PST 2006


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El Miércoles 15 de Febrero de 2006 17:06, Lennart Poettering escribió:
> I guess I'd call the AXIS cameras broken if they really configure
> themselves to the same static ip address, without user intervention.

No, the Axis cameras store the static IP address in their flash memory, so 
they don't automagically reconfigure themselves to the default 192.168.0.90. 
In most cases.

> I think it is more common to expect that static IP addresses are
> assigned carefully and without conflicts.

In my particular scenario, *I* have to carefully assign the static IP 
addresses. Of several devices at once. And double-check everything.

Call me lazy, but my goal is to make a set of scripts, using avahi, that 
automatically configures the cameras to use different static IP addresses. 
The process of assigning static IP addresses is booooring. Specially when 
there are more than 20 cameras.

> How many people do you know that have an AXIS camera?

Let me count how many customers does my company have :-)

[...]
> I still prefer to favour static ip addresses over IPv4ll ones. Static
> addresses are usually assigned manually and the user probably had a
> good reason to do so.

But there will still be cases where IPv4LL addresses are preferrable (such as 
mine).
Here goes an idea: make it optional. I would change some values 
in /etc/avahi/whatever and be happy.
Maybe there are some crazy scenarios (DNSs, ISP's and such) where a remote IP 
address is preferred. I think it all depends on the particular scenario.

> In addition they are don't change that often. In contrast to IPv4ll 
> addresses, which the user might not even know of, and which might change on 
> every reboot (or even more often!). 

And what's the problem with that? Bonjour, Avahi, Zeroconf, Howl et cetera 
take care of abstracting IPv4LL addresses so he user does not have to worry 
about them.

Also, most installations are unaware of IPv4LL addresses, so my algorithm 
would skip them (as they are not routable) and use the static local address.

> 1. if a locally reachable AND private address exists, use it, quit
> 2. if a locally reachable AND IPv4LL address exists, use it, quit
[...]
> Any objections? (Besides that you prefer IPv4LL over private
> addresses, which I don't, see above)

See above: make this an option, so an administrator can tweak this to the 
particular scenario.

> > [...] and by any chance you have got two devices in the same static IP 
> > (due to hard resets to the factory default, for example), what should 
> > happen? 
>
> I don't have that. I assigned them myself, and I am not an idiot ;-)

Well, some makers of embedded devices *are* idiot, and their devices *do* 
reset to the same IP. Try having two wireless bridges or APs at the same IP 
because there has been a blackout in the building and they have reset.

See, it's not that I think you're wrong at all. It's just that I'm a pessimist 
and a paranoid, and I always suppose the worst scenario. And I would like a 
tool to go back to normal as soon as possible.
By "worst scenario" I mean "big blackout, hundreds of mDNS-enabled cheap 
devices back to the factory settings". And by "go back to normal" I mean "set 
up different static IP addresses so the stupid windoze machines can talk with 
the devices".

<desperate>
And nothing can help me but Avahi...
</desperate>
<mafia>
So you'd better fix it, or my boys will "fix" you...
</mafia>

:-)



Best regards,
- -- 
- ----------------------------------
Iván Sánchez Ortega <ivansanchez at escomposlinux.org> <i.sanchez at mirame.net>

Sex is not the answer. Sex is the question. Yes is the answer.
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