Re: Setting UP DNS

[John Ross <jross-ml@xxxxxxxxxxxxxxx>]

Why? A private IP addresses  should be returned from a DNS query in the
answer. I know Internet routers are not suppose to forward traffic to
private IP addresses, but the private IP is in the answer. And then once
you get that you are on your internal network. Or is because most DNS let
you look at the zone file with NSLOOKUP or DIG and then a hacker can get a
pretty good idea of how your network is setup and IP addresses.

We really need to start saying why to do something and why not to, I know
it adds to the time to answer a post but it will help educate others. And
if a why is not included then the person asking the question should ask
why. And it may help the person answering the question learn something new.
Like me reasoning to do or not do something maybe wrong and some one can
say that is not correct. Like my reasoning to put DNS on a mail server,
that may or may not be correct any more someone else told me that, I have
no real experience with the speed of DNS on the mail server versus a second
machine just doing DNS. Is there a point where you are better off leaving
the mail server do mail stuff and  DNS to DNS stuff. With stuff changing
every week reasons probably change also. Like with 1 gig networks now does
having a DNS and a separate email server make more sense, at what volume of
email or speed of network does it. Or does the email server wait for the
response from the DNS server before it moves on anyway. What I am trying to
say is the more knowledge you have the better decision you should be able
to make.

A person needs to understand DNS before they just put it on the AS/400 or
any computer.  Do you want email down when the AS/400 is down? But my
AS/400 is not the mail server? But the DNS tells it where to deliver mail.
So set up a secondary DNS server, or have your ISP be the secondary.
problem solved. You have to understand that any place you convert a
computer name to an IP addresses will be affected if your one and only DNS
server is down, like file shares.

Or you may want to make your AS/400 a cache DNS, because it is your mail
server and you send email to the same people over and over. And this should
cut down on bandwidth for DNS request. More over head on the AS/400.

Sorry for ranting, but this thread has me fired up. We having him setting
up DNS without even finding out what the problem was.

John Ross

At 09:52 AM 7/31/02 -0400, you wrote:
>If you want to name resolve internal, private IPs, setup DNS on your AS/400.