I just started using the email proxy and have been getting some inconsistent
results with RDNS lookups enabled. I have a few issues:
1) RDNS appears to be using the internal DNS server for external addresses.
This may be by design but seems inefficient for our configuration. The
internal DNS is only for the private addresses on the protected network.
Where as, all the connections to the email proxy are from external
addresses, which get resolved by external DNS servers.
2) The SMTP proxy rejects connections for RDNS failures but when I do a
manual nslookup on the IP address it resolves to a hostname. Is there a
timeout issue here? I am not sure about the consistency here and weather a
particular host sometimes fails and sometimes passes.
3) When doing manual DNS lookup sometimes one or both of my internal DNS
servers do not return a hostname but the external DNS servers do. I can't
figure out why one returns a result and the other doesn't when they are
configured identically. This is probably a configuration problem with the
internal DNS servers (Windows 2000) and off subject for this list, however
it could be related so I list this symptom for completeness.
Below is some sample report data showing some of these details.
Date/Time: Jul 23 00:54:12
Source IP: 66.220.63.9
Message: smtp: Rejected (RDNS failure)
Results: RDNS=groupstudy.com
Date/Time: Jul 23 02:06:11
Source IP: 64.251.16.161
Message: smtp: Rejected (RDNS failure)
Results: RDNS=ftu-15.permissionpass.com.16.251.64.in-addr.arpa
Date/Time: Jul 23 08:01:06
Source IP: 63.209.16.170
Message: smtp: Rejected (RDNS failure)
Results: Name server results differ!
NS[1]: (failed)
NS[2]: (failed)
NS[3]: unknown.Level3.net
Date/Time: Jul 23 10:53:36
Source IP: 209.235.23.230
Message: smtp: Rejected (RDNS failure)
Results: RDNS=230-209.235.23.dellhost.com
Date/Time: Jul 23 21:21:10
Source IP: 65.121.184.27
Message: smtp: Rejected (RDNS failure)
Results: RDNS=65.121.184.27
--
John Stokes
888 336-0504
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
To subscribe to the digest version first unsubscribe, then
e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Archive of the last 1000 messages:
http://www.mail-archive.com/[email protected]
