Reverse DNS Multiple respsonses 2

[jvande]

We have a mail server at IP address 66.173.88.2. We have multiple mail records that point to this. mail.domain1.com, mail.domain2.com,mail.domain3.com. I am trying to configure reverse DNS to respond with all three domains instead of just one. Could someone give me some direction on how to do this? Email servers are using revers DNS to filter out spam and without this configured correctly email can't be sent to some customers.

Thanks

 

[ChrisAC]

You only need a PTR for one forward record. Having more defeats the object! Some do but I would not recommend it as you can't control which PTR is given as a response to a DNS request.

So, if you have domain1.com, domain2.com and domain3.com there is no reason why you can't have the following ...

domain1.com IN MX mail.domain1.com
mail.domain1.com IN A 66.173.88.2

>> in the zone file for domain2.com ..

domain2.com IN MX mail.domain1.com

>> in the zone for domain3.com ..

domain3.com IN MX mail.domain1.com

Then, in the 88.173.66.in-addr.arpa zone you only need ..

2.88.173.66.in-addr.apra IN PTR mail.domain1.com

Mail will then work for all three domains. If the mail server IP address changes then you only have to change one A record in one zone file (not all three) and the PTR will work correctly.

Chris.



**********************
Chris Andrew, CCNA, CCSA
chris@iproute.co.uk
**********************

 

[GlenJohnson]

Here's a star, Chris. Who says there isn't poetry in science?



Glen A. Johnson
If you're from Northern Illinois/Southern Wisconsin feel free to join the Tek-Tips in Chicago, Illinois Forum.

TTinChicago
Johnson Computers

 

[ChrisAC]

As Homer Simpson might put it ... Woo Hoo!!

;-)

Chris.


**********************
Chris Andrew, CCNA, CCSA
chris@iproute.co.uk
**********************

 

[GlenJohnson]

Doh!

Glen A. Johnson
If you're from Northern Illinois/Southern Wisconsin feel free to join the Tek-Tips in Chicago, Illinois Forum.

TTinChicago
Johnson Computers