Resolv local network names [Newbie question]
kcd at daimlerchrysler.com
Thu May 10 01:58:45 UTC 2007
Curt Sampson wrote:
> On Wed, 9 May 2007, Rafael Dewes wrote:
>> ...but now I need to resolve the LAN names, for example: I have the
>> machine 192.168.0.18 with the name flamingo.mydomain.com.br. Can I
>> setup it without configure a master or slave server?
> You can have it resolve for programs on your machine by putting an entry
> in /etc/hosts. "man hosts" for more details.
The original poster specifically asked about using BIND to resolve local
names. BIND doesn't use /etc/hosts for resolving queries.
> On Wed, 9 May 2007, Kevin Darcy wrote:
>> Well _somebody_ has to be master for the data...
> First, best to read this:
> and make sure you understand the following terms: domain name, zone,
> authoratative server. Now keep in mind, from the point of view of BIND
> and other popular name server daemons,
> A MASTER server is one that contains its own local copy of zone data;
> A SLAVE server loads its copy of the zone data from another server,
> and usually updates it regularly from that (or several) other servers.
> A master or slave will always be authoratative, though that doesn't
> necessarially mean that they're being delegated to via a path leading
> down from the root server. It's only the servers that are that will be
> "seen" by most systems on the Internet.
I said nothing about being in the delegation path, only that someone has
to be master for the data.
>> it's theoretically
>> possible that you could get your ISP or someone you know on the Internet
>> to serve as master, and then just forward to them, but since 192.168/16
>> is a private range, it's likely that other folks are already using it
>> for their own purposes, or they want to reserve the option of doing so.
> It doesn't matter at all that it's a private range; that has no
> connection with how records (at least, non-inaddr.arpa or "reverse"
> records) resolve.
Please read what I wrote. "... it's likely that other folks are already
using it for their own purposes, or they want to reserve the option of
doing so". Granted, being in a private address range doesn't *directly*
affect how DNS names resolve, but it may affect the *availability* of
other people and/or organizations to be master for the zone, and, as
noted above, someone needs to be master. If no-one is master, there is
effectively no zone, and therefore no resolvability. There's more to DNS
than just query/response transactions, there's a whole infrastructure
involved, and anything to do with infrastructure ultimately extends even
to "soft" factors like whether people are likely to provide a particular
service or not.
> For example:
> $ host lyric.cjs.cynic.net
> lyric.cjs.cynic.net has address 192.168.187.11
>> Besides, do you really want to have to co-ordinate every little internal
>> DNS change with an outside entity? Take control of your own destiny.
>> It's not that hard to set up a master zone. Just go ahead and do it.
> Right. But keep in mind that unless you've got some reasonably reliable
> and stable IP addresses on which to run your masters, you'll have to
> deal with some other way of making sure that all of your hosts of
> interest are using these servers or resolving servers that eventually
> query these ones.
For DNS and pretty much any other "core" network service, practically
speaking, persistent IP addresses are considered a prerequisite.
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