DNS Problem?

Unanswered Question
Jan 16th, 2008
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I am allowing specific internal hosts to relay through the Ironport. It works fine when using the IP address, but will not work using the hostname.

When telneted into the Ironport, I can ping the hostname, so DNS appears to be working.

DNS is setup as follows:

DNS Servers:

Priority IP Address
0 DMZ DNS Host IP (for DMZ computer host resolution)
1 ISP DNS Host - Primary
1 ISP DNS Host - Secondary

Overriding with the DNS Servers listed below:

Domain IP Address
internal.domain.com *.*.*.* (internal DNS server)

Typical internal hostname: computer1.internal.domain.com

Am I missing something here?



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Donald Nash Fri, 01/18/2008 - 01:00
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Sounds to me like the in-addr.arpa domain for your network either isn't set up or doesn't contain the PTR records for the hosts you want to allow to relay. Remember, just because you can look up "host.domain.com" in the DNS and get the right IP address, doesn't mean you can look up the IP address to get the name. The latter set up separately via the in-addr.arpa domain. This is what needs to work in order for AsyncOS to map from the IP address it sees on incoming SMTP connections to the host names you have listed in the HAT.


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