Hi,

I am stumped on how to work out my issue:

I have two boxes, 1- Centos router, 2- centos web/mail server..

When trying to receive mail using mail.xxx.xxx in the mail client server settings, it will not resolve to any machine on the internal network... I have to enter the internal IP address in the incoming and outgoing email settings..

Same with the website I host.. I have to enter the internal IP to get access..

It just will not resolve the DNS on the internal network.

Everything works as it should outside my network.

I am a bit of a noob but managed to get this far


Any help is greatly appreciated.

Hi and welcome to LQ,

The easiest way to do this, is to add in /etc/hosts:
where x.x.x.x is your server's internal IP

Regards

Wow, it couldnt be that easy?

Should I enter that in the GW or the mail/web server?

You should add it in your client box, i.e. the box you're using to access the mailserver or the webserver.
Of course it does not harm if you add it to any other internal box.
As I told you this is the easiest way, but if you have many boxes, it would be a waste of time to configure all of them. In this case you can use an internal dns, or a split (internal/external) dns to do your job.

Regards

Thanks, but i did do that with my main pc..

What i am trying to work out is a fix for the GW or my mail/web server which is also my main dns server.

I have >10 pc's that access mail on the network and outside as well..

One thing, i did have a simple netgear router that was a temporary fix while I was upgrading the GW and i did not experience this issue. It must be something with my firewall rules?

Hi,

First of all it's not a firewall but a dns problem, as you said you can access your servers with their IP addresses. And since you said it worked with the router, I guess the router was running dhcpd to assign IPs to your boxes along with hostnames.
Since you are running your own dns server, you should consider using views to distinguish between internal and external network

Regards

Thanks for the reply but it was my firewall..

I added- (xxx.xxx.xxx.xxx- your IP) GW is .254, Mail is .250
# Reroute public request to internal server :

$IPTABLES -t nat -A PREROUTING -d xxx.xxx.xxx.xxx -m tcp -p tcp --dport 80 -j DNAT --to-destination 192.168.1.250
$IPTABLES -t nat -A PREROUTING -d xxx.xxx.xxx.xxx -m tcp -p tcp --dport 143 -j DNAT --to-destination 192.168.1.250
$IPTABLES -t nat -A PREROUTING -d xxx.xxx.xxx.xxx -m tcp -p tcp --dport 993 -j DNAT --to-destination 192.168.1.250

#NAT Loopback for internal to public:

$IPTABLES -t nat -A POSTROUTING -d 192.168.1.250 -s 192.168.1.0/24 -j SNAT --to-source 192.168.1.254

Working perfectly now..

Anyone see any security issues with this?