DNS is frying my brain, One linux computer/virtual hosts

[waltwhit]

I have just recently came to the world of Linux. Two weeks ago I installed RH9 on an old PIII 866 in order to host two personal websites, and one for a local radio club. The default name of the machine as it was installed is localhost. And I see localhost.localdoman in different places.
Apache, and Dns is set up, and functional, and I am trying to incorperate sendmail. As I am doing this, i find amazement that DNS is working at all. I changed the NameServer record at my original nameserver to

http://www.waarc.com

(just picking one of the real domain names i owned) And got DNS working literllary by trial and error. I am using dns.secondary.org for the 2nd nameserver.
Now in my hours of reading on sendmail and DNS (as nothing i do seems to put a MX record in dns search or Notwork Tolls DNS Tool checks. I came across this and i qoute: "Two things must be noted about the SOA record. ns.linux.bogus must be a actual machine with a A record. It is not legal to have a CNAME record for the machine mentioned in the SOA record. Its name need not be `ns', it could be any legal host name."
So I am thinking, does this mean my machine name needs to be waarc.com or

http://www.waarc.com?

If so, how do i change it from localhost.localdomain. And if I do, wont that mess up everything i have set up with Apache and other programs?
All the examples I seem to find are for setting up one machine as 127.0.0.0 with it serving other machines, or 192.168.1.100 and serving other names. While i do have other computers and use a router with the 192.168.0.xxx, I dont want any websites hosted on those machines or to control them in anway with the linux machine.
For instance do I need all the reverse in-addr.arpa for the actual "internet ip 222.43.66 and the 0.168.192 and the 0.0.127 ?
I feel i am just missing the BIG Picture here.

RH9, Apache, Named, Sendmail, and Webmin are the programs i am using.

Any help would be greatly appreciated, thank you.

 

[wbg34]

My first tip to you would be to download webmin it will make configuration of these things much easier. Secondly, you will need to give your computer a host name (the default is localhost). To change that Click on the big red hat and select system settings --> network config. Click on the hosts tab. As far as what you name it that is up to you generally computers are named following the name.domain.com convention. As far as it messing up other settings I just kept localhost.localdomain as an alias to cover that. I would keep this dns server seperate from your internal network (external ip for reverse lookup).

 

[waltwhit]

obviously i am in the wrong job,and need a management position

 

[waltwhit]

wbg34, that helped, or at least it did not damage much, when i changed the machine name, i left it alias to localhost, I also changed the dns servers listed, but had to change them back as i could not find anything on the internet. Only problem was the rpm lookup and i reconf it so it works again now.
Unfortunately, i am still lost. Again i am not using this on a network persay, each of my computers has direct access to the internet, and I am just using the linux to host websites/provide a mail domain for those websites.

 

[Norwich]

Hi,

It is common practice in LInux installations to have both localhost and the 'proper' hostname defined. Have a look at /etc/hosts. You'll have something like:

127.0.0.1 localhost localhost.localdomain
aaa.bbb.ccc.ddd mymachine mymachine.mydomain

Now, you still use the 'hostname' command to set the 'real' name of the machine and domain but the above /etc/hosts file will still let the various installations for mail and web servers etc reference localhost.

Note, for a simple mail installation, sendmail may be too OTT config-wise. You may want to consider postfix and exim that are simpler to configure and have sendmail compatability.

 

[waltwhit]

I thought about using Postfix, as I have been using the reference book, Red Hat Linux Internet Server . What I was worried about, is I have 3 websites up, and running, they all have postnuke, and ppphb forum on them. Both these programs, seem to be using the installed sendmail program on their own, because they send out newuser passwords. I quess i can check the config on those programs and see if there is a place to change it,if i install Postfix. I was just worried about something that is working now, not working and loosing ground in this battle.

 

[Norwich]

Postfix is useful for migrating in that it contains it's own 'sendmail' executeable that spoofs what sendmail does. So that applications that spawn sendmail directly (rather than connect to port 25) can do the same with postfix via this 'sendmail' interface. See:

http://postfix.behrsolutions.com/sendmail.1.html