Reverse DNS lookup is the determination of a domain name that is associated with a given IP address using the Domain Name System (DNS) of the Internet.

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How to get reverse DNS to work for multiple IPs and domains on Windows Server EC2 instance?

I have a EC2 instance setup running hMailServer. I have a primary IP on the system that I am using for example1.com email. I would like to also add a second domain example2.com using a different IP ...
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13 views

Deleting reverse zone in windows 2003 DNS server

This is my first time posting here on server fault. The problem i am faced with is when i try to add another DC to my network i am getting a very weird error. After some countless hours and re-reading ...
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2answers
42 views

Reverse DNS entry when using “external” dns server

Administrator of my company allowed me to put my own server in our datacenter and gave me one public address of our AS pool. I've installed linux and configured basic services. Then i've added A ...
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1answer
40 views

The correct PTR record in DNS

I'm confused with my DNS records. I own a domain (e.g. example.com).I've set A record for my SMTP server (e.g. smtp.example.com) for outgoing emails. The email address is (e.g. ...
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52 views

How to setup reverse DNS record (PTR) with Webmin?

Sorry, my knowledge in IT is very limited so please kindly forgive me if this is a stupid question. I have a very simple Centos VPS with Webmin installed on mysite.com with IP 123.456.789.5 ...
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22 views

rDNS and hostname conflict

My server has 3 IPs: 2 for dns stuff for example 192.0.2.1 and 192.0.2.2, and one that I use for outgoing email, let's say 192.0.2.3. My hostname is mail.mydomain1.com. The problem began when I ...
17
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1answer
899 views

Do internet standards require reverse DNS for every device?

The requirements surrounding reverse DNS are confusing! People frequently talk about everything breaking if reverse DNS is not present, and that sounds scary. Even in cases where applications don't ...
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25 views

Remove Port Access Using mod_rewrite or Something Else

Server Info: Apache VPS, WHM/cPanel, CentOS I am using a CDN/reverse proxy (Cloudflare) to obscure the true IP of my server. So I intend to access WHM/cPanel using the direct IP like this: ...
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41 views

Reverse DNS zones, are they gluable?

Our DNS infrastructure is a bit fractured. We have multiple separate DNS servers for different parts of the company. However, we do still have some interchange issues. Right now a server from ...
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121 views

Zimbra SMTP Reverse DNS Mismatch

I have a Zimbra email server. sending and receiving is fine, however When I use online tools to check that things are configured properly, I'm being told my reverse DNS SMTP Banner is wrong. ---- ...
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1answer
71 views

Two servers, severals domains, reverse DNS and blacklist

I will try to explain the context. 2 VPS with PLESK 11.5 The first (named vps67877.ovh.net - we call it v67) is a mail server (ip 37.187.33.38) The second (named vps68789.ovh.net - we call it v68) ...
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3answers
139 views

Get IP network range after reverse DNS?

For analytics purposes, I'm looking at large sets of IP addresses in server log files. I'm trying to perform reverse-DNS lookups to understand where traffic is coming from - e.g. what percentage of ...
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36 views

Cisco DNS Inspection disallows Reverse Lookup

I'm trying to use DNS Doctoring on my ASA 5505, but apparenly DNS Doctoring required DNS Inspection, and DNS Inspection forbids reverse lookup requests?! How do work around this? I did find this: ...
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1answer
218 views

Reverse lookup SERVFAIL

I just set up a DNS server and a web server using Virtualbox. The IP address of the DNS server is 192.168.56.101 and the web server 192.168.56.102. Here are my configuration files for the DNS server: ...
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1answer
53 views

Dns filezone setup with mx and spf

I am trying to create a mail server. I bought the domain mastermails.info on godaddy.com. I am struggling with the setup of DNS. Whenever I change something in the MX record to make my server ...
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1answer
48 views

Is there a way to use Bind9 $GENERATE directive for rDNS of ranges bigger than /24?

The $GENERATE directive of bind9 makes it possible to autogenerate the reverse mapping for a range of IPs what is really helpfull for reverse dns of a dhcp range. But it seems that the $GENERATE ...
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2answers
1k views

Are PTR records added only by the ISPs that provide and manage the IPs?

I checked out with my DNS provider to change the PTR records: Dear Sir, We can not modify the PTR records of the IP addresses that you provided, because these IP addresses are not managed ...
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1answer
377 views

Comparing 2 CSV files in powershell exporting difference to another file

I've write this script out, and could have swore I had it giving me a Failed early this morning but now I'm getting nothing and not sure why. Basically I need to compare $SourceAddress with ...
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1answer
40 views

What domain to set in rDNS

I have a few different domains on a shared IP address. One of them is having trouble sending email, as certain mail servers reject the email for not having rDNS set up properly. The thing is there ...
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1answer
78 views

Powershell pipe exporting to csv is loosing data

I'm trying to write a script that will take input from a .txt file of IP address. Do a reverse DNS lookup to get the hostname of the IP address and then export that data into .csv file. Here is what ...
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0answers
3k views

server can't find XXX.in-addr.arpa: NXDOMAIN

I am facing problem while configuring BIND DNS sowing server can't find XXX.in-addr.arpa: NXDOMAIN while reverse dns check! everything works on forward DNS lookup but reverse DNS lookup fails. Here ...
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1answer
81 views

Do reverse entries for name-server, need to match the mailserver name?

I need to setup PTR for a domain and lets say my domain is domain.com and I have my email addresses like email.address@domain.com. I came over this mailing-list article that says: The reverse ...
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1answer
154 views

Forwarder dns not resolving reverse lookups

I have created one new dns server in lab and its working properly. Earlier we were using another dns server for lab pc's as 10.20.30.xx. which is outside the lab premises. now issue with newly created ...
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1answer
40 views

Delegate NS resource record of IPv4 subnet

Is it possible for a reverse zone to name another DNS server in the NS record? I want to delegate DNS for all addresses within a subnet to a site using that subnet. Our office leases a subnet which is ...
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1answer
47 views

Way to find all domains that have a CNAME to my domain? [closed]

I have a web service that allows users to white-label our software by using their own domain over ours. This is done by the user adding a CNAME record from their domain to our domain. Is there a way ...
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135 views

Azure public/private dns resolution

Does anybody know if Azure has the same capability as AWS to resolve an external DNS hostname to the public IP address of the instance outside the network of the instance, and to the private IP ...
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1answer
79 views

How to DNSSEC Sign Bind9 Reverse Zone

I'm using bind9 and dnssec-keygen/dnssec-signzone. I've had no problem signing my forward zones however I cannot seem to find any documentation on signing reverse zones. What is the process for this?
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1answer
98 views

Bind9 reverse DNS configuration not working.

I am trying to set up a custom virtual DNS server in Ubuntu. When I try to nslookup with a windows 7 pc within the same virtual environment the reverse DNS seems te fail. My named.conf.local file: ...
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2answers
593 views

Postfix: bouncing mail (reverse DNS issue)

I have a problem with Postfix. I get this with some email address: to=<mail@domain.tld>, relay=mail.domain.tld[IP_ADDRESS]:25, delay=3, delays=0/0/2.5/0.52, dsn=5.7.1, status=bounced (host ...
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2answers
388 views

sshd tries reverse DNS lookups with UseDNS no

sshd seems to almost always try to perform a reverse DNS lookup on new connections. For hosts without a PTR entry this causes delays of 5 seconds per query. Sometimes it accepts the connection ...
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1answer
219 views

How to set up reverse DNS on Ubuntu 12.04 VPS

As far as I can remember when setting up my VPS and mail server on it, I had configured the mail server correctly. However, a few of my clients get SMTP errors, host mx1.zonnet.nl[62.58.50.9] ...
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124 views

Bind9 on Debian : nslookup point on localhost not my ip server

i have just install bind9 on Debian. I think i haven't configured not everything because i still have a problem with the DNS and the propagation. I think the problem is say by nslookup : Server: ...
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43 views

Confusion about rDNS

I am slightly confused as to what has to go in the rDNS settings of my IP. Consider the following scenario: IP: 1.2.3.4 Domain 1: foo1.bar @ A 1.2.3.4 @ MX mail.foo1.bar www CNAME ...
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2answers
132 views

unable to resolve IP in reverse DNS

This question itself has been asked before several times, but none of the answers given there has worked for me so far. So probably I'm doing something wrong, and I can't figure out what. I'm running ...
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1answer
280 views

PTR records with Windows DNS Server not working

I am trying to create a PTR record on my domain (kentrosecafe.com.au) so that I can get reverse DNS lookups working. The DNS Server I am using is the Windows DNS server which is on a Wiindows 2012 ...
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1answer
37 views

Why we have always two ips as DNS Entry [closed]

Why we have two IPs for dns entry like in Google DNS - 8.8.8.8 8.8.4.4 Or as in OpenDNS - 208.67.222.222 208.67.220.220 Also in router settings, it shows always 2 ips for DNS. Any specific ...
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1answer
80 views

how to find if there is …in-addr.arpa delegated?

I have ip pool, but reverse dns does not works. It works if lookup on ns server. Does not works in internet. I requested registrator to delegate this pool to ns1.mydomain. I added net IN NS ...
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1answer
192 views

Reverse DNS to match Sophos name, or mail server name

I think this is a simple question with a simple answer. Our domain, cory.co.uk, reports a DNS mismatch when you do and SMTP test on mxtoolbox.com. I think this is causing issues sending to some ...
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1answer
166 views

ping -a sometimes returns host name and sometimes returns FQDN. Why? Does this mean DNS is corrupt somehow?

I have a Windows machine called abcd for example and it uses DHCP to receive an IP address (172.28.45.5 for example) When I perform ping -a 172.28.45.5 sometimes I receive abcd as the hostname. ...
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2answers
554 views

How can nslookup on an IP address return NXDOMAIN but I can still ping it?

I was trying to do some reverse DNS lookups on some IP addresses I see in my traceroute (ultimately to figure out roughly geographically where my path is going through), but I often get results that ...
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1answer
45 views

Is the ReverseLookup zones important to a DNS server?

We simply have none. I am a humble software programmer, with insignificant networking knowledge, but there are not any network admins to turn to where I work. I looked at the DNS server out of ...
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0answers
132 views

BIND9 / DNS Zone / Dedicated Server / Unique Reverse DNS

I locate a dedicated server in a datacenter with no DNS Zone setup. Datacenter panel have 1 textfield only you can fill one Reverse DNS only. According with datacenter instructions here... ...
2
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1answer
74 views

Wildcard DNS like “*-test.example.com”

Is it possible to set up a wildcard domain like "*-test.example.com"? The main reason I'm asking is because I'm in the process of setting up Continuous Integration with Jenkins, and we'd like to ...
0
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0answers
53 views

BIND9: How to forward to another DNS specific reverse lookup

I'm trying to fix one issue with my DNS but can't find information for how to do it. I have few separate DNS with different zones. Primary DNS handle quite good with local domanin but should also ...
5
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2answers
144 views

How to determine which DNS server has the authority to set rDNS (PTR records)?

or to re-phrase... How to determine to whom authority has been delegated to set rDNS? Background In a multi-tier environment, where a block of IP's is assigned, then further split and assigned ...
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5answers
390 views

Is it good practice or too draconian to reject mails from mailservers with no RDNS

I've recently dropped SpamAssassin and am now basing spam rejection on DNSRBL's, grey-listing and other basic tests and I'm wondering whether I should also block hosts that don't have a valid RDNS ...
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1answer
90 views

Reverse dns for web/mail server with single ip

I have a single server with single ip running a web server, mail server and bind (all for a single domain). In my DNS zone file I created A records for www.domain.com, mail.domain.com, ns.domain.com ...
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166 views

Some E-mails are being rejected, do I need a DNS record for my default gateway?

I have been seeing more of these types of bounceback messages (IP address changed for example): mail.test.com #550-Your message was rejected by this user and was not delivered. 550-Reason: Your ...
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226 views

Mysql remote connections very slow - host lookups already disabled

I followed every instruction about this issue and nothing helped. Remote communication with MySQL server takes 4-30 seconds on simple query like select 1 from table_name and connection attempt often ...
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1answer
86 views

Reverse dns and SaaS Spam Filters

We have an exchange server in the office that for a year or so has just used the built-in spam filters - we have added the SpamHaus IP addresses so that some basic spam filtering is done. However, ...