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Old 7th October 2006, 06:18
VMartins VMartins is offline
Join Date: Aug 2006
Location: Sao Paulo - Brasil
Posts: 70
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Question DNS Configuration Problems

Hey All,

I'm having some dificults to setup my DNS. The first problem was my knowlegde... This problem I solved. The second problem is the ISPConfi automatic configuration of Bind Confs.

I test my DNS conf with DNSReport ( and I have many warns and erros. Follow the tips I try to solve this issues. But this automatic config don't leave me to manual configure my confs. For example, I have 3 DNS entries, but ISPConfig support only two entries. I want to configure the DNS Reverse Lookup, but the automatic conf doesn't have the correct code.

Follow the warns and fails fo DNSReport about my domain (

1 - FAIL Open DNS servers ERROR: One or more of your nameservers reports that it is an open DNS server. This usually means that anyone in the world can query it for domains it is not authoritative for (it is possible that the DNS server advertises that it does recursive lookups when it does not, but that shouldn't happen). This can cause an excessive load on your DNS server. Also, it is strongly discouraged to have a DNS server be both authoritative for your domain and be recursive (even if it is not open), due to the potential for cache poisoning (with no recursion, there is no cache, and it is impossible to poison it). Also, the bad guys could use your DNS server as part of an attack, by forging their IP address. Problem record(s) are:
Server reports that it will do recursive lookups. [test]
Server reports that it will do recursive lookups. [test]

See this page for info on closing open DNS servers.

2 - FAIL No NS A records at nameservers WARNING: Your nameservers do not include any corresponding A records when asked for your NS records. They probably are not returning the A records when asked, which can prevent some other DNS servers from contacting your DNS servers. They should do this if they are authoritative for those A records. The problem record(s) are:
Nameserver did not provide IPs for all NS records.
Nameserver did not provide IPs for all NS records.

3 - FAIL Reverse DNS entries for MX records ERROR: The IP of one or more of your mail server(s) have no reverse DNS (PTR) entries (if you see "Timeout" below, it may mean that your DNS servers did not respond fast enough). RFC1912 2.1 says you should have a reverse DNS for all your mail servers. It is strongly urged that you have them, as many mailservers will not accept mail from mailservers with no reverse DNS entry. You can double-check using the 'Reverse DNS Lookup' tool at the DNSstuff site (it contacts your servers in real time; the reverse DNS lookups in the DNS report use our local caching DNS server). The problem MX records are: [No reverse DNS entry (rcode: 3 ancount: 0) (check it)]

Somene has the same trouble? Any help or information is very welcome.


Sao Paulo - Brasil
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