[CentOS] Is avahi essential?
Les Mikesell
lesmikesell at gmail.com
Sat Jan 14 16:56:52 UTC 2012
On Sat, Jan 14, 2012 at 8:17 AM, Timothy Murphy <gayleard at eircom.net> wrote:
>
>>> Isn't that more or less what I said above?
>>
>> It's almost the opposite. mDNS does name->IP and let's people
>> find other machines; DHCP does MAC->IP and let's a machine find _itself_.
>>
>> Or, another way of looking at it. mDNS is a bit like ARP, but for names.
Somebody already said this but it isn't just host names, it is for
services and the ports they run on.
> OK, I should have said "a rival to ARP + dhcp".
> As I see it, dhcpd assigns IP addresses to the devices on a LAN,
> and arp then provides a method of accessing a device
> with a given IP address.
>
> Incidentally, I don't really see why mDNS is needed on a LAN.
> If a program wants to know the IP address of a device with a given name,
> why can't it just look in /etc/hosts ?
Devices aren't really the point. Start a second copy of mediatomb
somewhere. Change the port it runs on. Start 2 copies on the same
server on different ports. Tell the ps3 to find them. Where is the
ps3's /etc/host file? How would you edit it - and if you could, how
would you describe 2 of the same service on the same device? If I
turn on a sony laptop running windows7, the ps3 sees both the windows
media server and the sony vaio instance of the similar service.
> I see that it might be useful in a much simpler setup,
> where there is no server;
> but if there is a server available, I don't really see the point of it.
A visitor with a laptop uses your wifi and would like to print
something. With apple's bonjour (which can be installed on windows
too, and avahi probably matches) he'll see a list of available
printers without having to configure anything. Isn't that nicer than
having to match IP/name/protocol/port up yourself all with different
configuration concepts?
--
Les Mikesell
lesmikesell at gmail.com
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