This has been commented on in part, but it's got some things wrong enough I
want to emphasize them:
On Thu, Jan 03, 2002 at 10:18:50PM -0600, Gary wrote:
> Hi Julian, A /etc/hosts file is not a named daemon.
True.
> It will not resolve name and address, only DNS does that, i.e. BIND.
> The Hosts file will go by IP addresses only, and not names/aliases..
Oh, this is terribly wrong! That's exactly what the hosts file provides--
name to IP mapping. The need for DNS grew out of our experiences with
hosts files.
The difference--both in function, and complexity-- between DNS and hosts
mapping is that it's only visible on the local machine. The reason DNS
came about is that managing hosts files on multiple machines became
too unwieldy. Once a service was envisioned, many of the additional
features of DNS were logical (MX, CNAME); and the management trappings
were necessary to allow the distribution and management of the information
(SOA, NS, etc.)
Finally, only (relatively) recently were much of the security features
of DNS added to handle the evolution of the Internet from a small,
friendly group. (the identification and restrictions available in
the named.conf file).
> This is more of a local protocol on a small network, versus a DNS
> daemon, which is more global going out onto the net, and working with
> several networks, and subnets.
True in concept, although actually hosts is just one of any number of
resolution methods used by the resolver, not a protocol in its own right.
> This provides for reverse name and address lookup, with SOA's (start of
> authority) records, etc...
SOA records are just an administrative requirement of the networked
environment in which bind operates.
> Now BIND will set up a local resolver and use hosts, but it just
> looks there first anyway...
Well, it only looks there first if 'hosts' is the first entry in the
file /etc/hosts.conf. That file is used to tell the resolver routines
what order in which to query the name resolution sources for the system.
> it is easier just to use hosts for a small network by IP instead of
> name and address resolution..
Hosts IS a "name and address resolution" method. This is true, but
should be stated that "it's easier to just set up hosts fora small
network instead of a local DNS server".
> The only difference instead of saying "Bob's box", you have to punch out
> some octets.. <g>
This is false. You have to come up with the octets to build the
hosts IP-to-name mapping, but thereafter everything looks, to user
programs and the user interfaces, the same as if they were running DNS.
The administrator uses different tools and methods than with a DNS
configuration.
Cheers,
--
Dave Ihnat
[EMAIL PROTECTED]
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