Good Morning,
I have a question to the following scenario:
My ASG has two uplink interfaces and uplink balancing is active, a multipath rule is defined to force all outgoing smtp traffic on the first WAN-interface WAN1. It exists a mx-record and rdns-entry for the ip-address / hostname of WAN1. The second WAN-interface should send and receive mails in case of failover (e.g. WAN1 is offline). I think that I should expand my mx-record and define a rdns-entry for WAN2:
WAN1
====
IP: 1.2.3.4
DNS: mail.xyz.com
RDNS: 1.2.3.4 -> mail.xyz.com
MX-Record: xyz.com -> mail.xyz.com (with higher priority, e.g. 10)
WAN2
====
IP: 6.7.8.9
DNS: mail2.xyz.com
RDNS: 6.7.8.9 -> mail2.xyz.com
MX-Record: xyz.com -> mail2.xyz.com (with lower priority, e.g. 50)
In that case both interfaces can send outgoing mails and receive incoming mails, is that correct? The only problem is the configuration of SMTP hostname where I only can define one hostname. I think some mail server check if the smtp hostname (helo) belongs to the ip-address, in this case that wouldn't work.
Another idea is to use the same rdns-entry for the second WAN-interface:
WAN2
====
IP: 6.7.8.9
DNS: mail2.xyz.com
RDNS: 6.7.8.9 -> mail.xyz.com
MX-Record: no change needed
In that case the smtp hostname (helo) belongs to the ip-address but the resolution of the smtp hostname return the ip-address of WAN1. If I add an additional ip-address to mail.xyz.com external mailserver would use an ip-address for our mailserver with round robin. That's not what I want.
Has someone an idea?
Thanks and kind regards
Christian
This thread was automatically locked due to age.
