domain blocking for DNS

[Jeremy Fowler]

Well, forward DNS -yes. Reverse is not so easy. If the company purchased a full block of IPs, 
keeping reverse DNS up2date is easy. However, if you don't need 254 IPs, your ISP may subnet's your 
last octet. Then it's hard to keep an actuate reverse DNS table since DNS is limited when working 
with subnet'd octets and you usually have to coordinate with your ISP.

> -----Original Message-----
> From: Hanasaki JiJi [mailto:hanasaki at hanaden.com]
> Sent: Thursday, May 08, 2003 11:28 AM
> To: List - KCLUG
> Subject: domain blocking for DNS
> 
> 
> Adding a parallel thread to "domain blocking due to spam".
> 
> Some of you might have noticed a msg sent to me via the list 
> becuase the 
> sender was being bounced when sent directly.  I recently added a 
> configuration to my mailserver to reject connections from 
> sources that 
> do not have forward/reverse DNS setup.
> 
> This resulted in alot of rejections from ligitimate companies and 
> induviduals!  It was put into place becuase some spam seems 
> to come from 
> telnet sessions on an IP that has no DNS / ReverseDNS entry.
> 
> Do you folks think it is reasonable to expect admins to have both DNS 
> and ReverseDNS propperly configured?  at least for their outgoing 
> mailserver?
> 
> Thanks
> 
> 
> 
> majordomo at kclug.org
>