digital ocean setup-droplet basic tutorial/questions

[Tim]

Allegedly, on or about 16 January 2016, bruce sent:
> The goal is to get a basic sys admin understanding of DNS, and how to
> apply it to a few instances/VMs.. Over time, the number of machines
> will increase. Simply doing the etc/host isn't reasonable. 

I that case, I'd say look into learning BIND.  It's a complete DNS
server as used in various places.  I don't think playing with a cut
down, or limited feature DNS server is worth the bother.  Though the
basic one that Fedora has will let it read the /etc/hosts file on that
particular machine, for it to resolve queries for.

It all depends on whether you want to learn how to use DNS, or just
figure out one particular server software.

You'd approach it in a similar way to my prior message, about either
using some commonly used LAN domain names, or registering a real one
(which has benefits that you'll appreciate in the future).

Set up DNS records using that name, set up your DNS server to resolve
those queries, and to resolve your clients queries about the rest of the
web.  Set up your clients to use that DNS server.  The "domain" or
"search" parameter in /etc/resolv.conf will append the domain name to
any hostname that you use.

e.g. "ping two" would expand into being treated as if you'd typed "ping
two.localdomain".

If you're setting DNS records for your clients, then you need to make
sure that they always use the same IP, either by manually setting them
that way, or using DHCP to always give them the same IP.

The alternative is have a DNS and DHCP server that talk to each other,
and each time the DHCP server gives a machine an IP, it puts the
information about it into the DNS server.

Well, actually they're not mutually exclusive ways of doing it.  My LAN
uses machines in all those ways.  The main server has an IP fixed by its
own configuration.  The usual clients have IPs fixed by the DHCP server.
And guests get the full automatic treatment by the DHCP server.  With
the DHCP server informing all clients of the local DNS server address.

Other than the occasional bit of problem solving, I haven't had to refer
to a machine by its numerical IP in many years, I've always used
hostnames.

-- 
[tim at localhost ~]$ uname -rsvp
Linux 3.9.10-100.fc17.x86_64 #1 SMP Sun Jul 14 01:31:27 UTC 2013 x86_64

Boilerplate:  All mail to my mailbox is automatically deleted, there is
no point trying to privately email me, I only get to see the messages
posted to the mailing list.

Windows, it's enough to make a grown man cry!