Simple questions on hostname and basic concepts

General support questions
Post Reply
bluesnow
Posts: 1
Joined: 2014/04/15 09:58:30

Simple questions on hostname and basic concepts

Post by bluesnow » 2014/04/15 10:30:28

Yes, there's many articles on how to change hostname etc but I'm having a hard time understanding the basic concepts!

I have the following:

VPS instance: host123.ovh.net / IPv4 987.654.321

Regged domain ABCDE.com. --Namervers are kept another net (not OVH).
On that net I've done the A/AAA/CNAME records pointing to IPv4 987.654.321.

I can set reverse IP in OVH control panel.

I'm confused if I should change my host name to my FQDN with or without an actual hostname.

For example; if I set HOSTNAME="BOX.ABCD.COM" then how would the box perform www and mail/smpt correctly ?

Let me get this right, or at least have a guess!! >

Client asks "where is http://www.ABCD.COM"
Client finds com > ABCD > 987.654.321
Client says "I want www from your domain"
Apache says "I am BOX.ABCD.COM and I'm qualified to provide http://www.ABCD.COM... or even just ABCD.COM

Is that correct ?
Seems like a broken hierarchy and that's what I'm having problems understanding.

fredvps
Posts: 61
Joined: 2014/03/13 22:05:19

Re: Simple questions on hostname and basic concepts

Post by fredvps » 2014/04/16 11:25:38

bluesnow wrote:Yes, there's many articles on how to change hostname etc but I'm having a hard time understanding the basic concepts!
I feel your pain. (and can echo exactly the same issues...)

Unfortunately linux has little or no documentation at all.
There are tons of mostly outdated or inapropriate texts
but that's not the same as documentation. A fact that
totally eludes certain groups of people.

This is the reason I choose centos over any other
insane implementation - at least there is an attempt at basic
stability. It isnt very good but its probably the best we can get
from what is at the end of the day - a community project.

markkuk
Posts: 739
Joined: 2007/09/07 10:56:28
Location: Finland

Re: Simple questions on hostname and basic concepts

Post by markkuk » 2014/04/16 12:03:10

bluesnow wrote: For example; if I set HOSTNAME="BOX.ABCD.COM" then how would the box perform www and mail/smpt correctly ?
The hostname is locally maintained by the kernel and completely separate from DNS domain names. Hostname setting has no effect on Internet services like WWW and mail. Unfortunately some documents incorrectly use the term "hostname" when they really mean "domain name".
bluesnow wrote: Let me get this right, or at least have a guess!! >

Client asks "where is http://www.ABCD.COM"
Client finds com > ABCD > 987.654.321
Client says "I want www from your domain"
Apache says "I am BOX.ABCD.COM and I'm qualified to provide http://www.ABCD.COM... or even just ABCD.COM

Is that correct ?
No.
Client asks the DNS resolver for an IP address for www.ABCD.COM
DNS resolver replies "123.123.123.123"
Client connects to port 80 of 123.123.123.123 and sends a HTTP request
Apache responds either with the requested resource, a redirect or an error message.

Post Reply