Setting up subnets

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October 22nd, 2001, 09:49 AM

danp

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Location: Sheffield, UK

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Setting up subnets

Hi there, this is an extention of a topic I posted in the Apache forum but got asked to move it here. I have several virtual hosts set up, all of them working fine. My main domain is www.actconsult.net with several subnets pointing to out IIS server (intranet. demo. and test.) These all work fine.
I also want to set up some subnets that actually reside on the server and have thus set up virtual a host for sql.actconsult.net.

Code:

<VirtualHost 213.205.145.246>
	ServerAdmin webmaster@actconsult.co.uk
	DocumentRoot /home/sites/sql/web
	ServerName sql.actconsult.net
	ScriptAlias /cgi-bin/ /home/sites/sql/cgi-bin/
	ErrorLog /home/sites/sql/logs/error.log
	CustomLog /home/sites/sql/logs/access.log combined
</VirtualHost>

I was unable to find any documentation to help me so first I set up a new zone - obviously that's wrong.

I have now have this in the nameD file for actconsult.net:

Code:

$ORIGIN net.
actconsult	43200	IN	SOA	dns1.actconsult.net. hostmaster.actconsult.net. (
		2001102202 3600 900 1209600 43200 )
	43200	IN	NS	dns1.actconsult.net.
	43200	IN	NS	dns2.actconsult.net.
	43200	IN	MX	5 mx1.actconsult.net.
	43200	IN	MX	10 mx2.actconsult.net.
$ORIGIN actconsult.net.
ns1	43200	IN	A	213.205.145.246
dns1	43200	IN	A	213.205.145.246
ns2	43200	IN	A	213.205.145.242
dns2	43200	IN	A	213.205.145.242
ftp	43200	IN	A	213.205.145.246
msg	43200	IN	A	213.205.145.242
mx1	43200	IN	A	213.205.145.242
mx2	43200	IN	A	213.205.145.246
www	43200	IN	A	213.205.145.246
sql	43200	IN	A 	213.205.145.246	
test	43200	IN	A	213.205.145.242
demo	43200	IN	A	213.205.145.242
intranet	43200	IN	A	213.205.145.242
@	43200	IN	A	213.205.145.246

This all works fine except for the sql.actconsult.net bit.

Hope you can help.

October 22nd, 2001, 09:19 PM

freebsd

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A DNS lookup of sql.actconsult.net resolves to 213.205.134.246 instead of 213.205.145.246.

Change the order of your A records to:

ns1
ns2
mx1
mx2
...
...

They need higher preference than others.

October 26th, 2001, 04:40 AM

WuzWuz

Junior Member

Join Date: May 2000

Location: Heerlen, The Netherlands

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Re: Setting up subnets

Quote:

Originally posted by danp
[snip]

Code:

$ORIGIN actconsult.net. ns1 43200 IN A 213.205.145.246 dns1 43200 IN A 213.205.145.246 ns2 43200 IN A 213.205.145.242 dns2 43200 IN A 213.205.145.242 ftp 43200 IN A 213.205.145.246 msg 43200 IN A 213.205.145.242 mx1 43200 IN A 213.205.145.242 mx2 43200 IN A 213.205.145.246 www 43200 IN A 213.205.145.246 sql 43200 IN A 213.205.145.246 test 43200 IN A 213.205.145.242 demo 43200 IN A 213.205.145.242 intranet 43200 IN A 213.205.145.242 @ 43200 IN A 213.205.145.246

This all works fine except for the sql.actconsult.net bit.

Hope you can help.

You should not use A records for canonicals, but CNAMEs.

Code:

ns1 IN A IP-address
www IN CNAME ns1
sql IN CNAME ns1

October 26th, 2001, 04:59 AM

freebsd

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>> You should not use A records for canonicals, but CNAMEs

There no longer is such thing as CNAME one earth. Don't use CNAME, just multiple A records to do the same thing at all time.
CNAME lookup is unreliable and require more bandwith and resource. To lookup a CNAME, you must first lookup the A record of associates FQDN. That's a waste of resource.
When you are running your own mail server + authoratative DNS server yourself, using CNAME is strongly discouraged.

October 26th, 2001, 05:25 AM

danp

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Location: Sheffield, UK

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Thanks guys, it was actually correctly configured. Somehow the name demon got switched off and then our DNS2 had incorrect information about the SQL subnet.

I'm slowly getting used to Linux configuration. Cheers!

Setting up subnets

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