Re: A Quickhack

On Sun, Oct 26, 2003 at 01:32:37PM -0500, Alan DeKok wrote:
> 
>   Let's try an example.
> 
>   mail.example.com == 1.2.3.4
>   ftp.example.com  == 1.2.3.5
>   *.3.2.1._asrg_rmx_.example.com = "permitted to send smtp"
> 
>   A recipient MTA receives a request from 1.2.3.4, but the EHLO says
> "ftp.example.com". 


I think this is a bad example, because the machine is misconfigured.
Misconfigured machines are alway a problem of their own.


I would give another example which is not far away, but 
meets my experiences, the already mentioned NAT problem:


relay.example.com    = 192.168.1.1
firewall.example.com = 1.2.3.4


Now the relay opens a connection and gets NATted to 1.2.3.4, 
while the DNS A PTR for relay.example.com is 192.168.1.1

This is a common mistake in DNS configuration.

Do we require people to have a proper DNS configuration or do 
we do a "workaround" for bad DNS entries?

Hadmut