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Questions tagged [reverse-dns]

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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[DNS][BIND9] Forward to external IP when clients request external domain name

So, I have some dns where I have setting with many internal zones for my domain yyy.com. And I need add record to provider server (host - with configuration files to download, this not some DNS like ...
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2answers
380 views

domain name system - rDNS is not exist [closed]

I need some help with Reverse DNS as I have got a problem with it. I have setup rDNS on my hosting provider which I use rdns1.example.com and I have a server hostname which it is gateway1.example.com. ...
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0answers
31 views

PowerDNS AXFR - ;; communications error to x.x.x.x#53: end of file

Using PowerDNS, we got into an issue with transferring a single domain object (/24) from our primary to our secondary DNS server. This /24 is part of a larger RIPE block, /22, and is not ...
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0answers
39 views

MTA poor reputation [duplicate]

I'm facing MTA poor reputation and I'm fighting against it since days without success. MTA poor reputation had plenty topics so I verify/modify many aspect of my configuration such as: Verify ...
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0answers
11 views

Postfix myhostname attribute and rDNS

I run a mailserver on Ubuntu using Postfix to serve a domain I have. Let's call it domain.com. For this domain, I have the follow DNS records: A domain.com 1.2.3.4 A mail.domain.com 1.2.3.4 MX ...
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1answer
35 views

rDNS — more than one IP per server?

Very simple question that I can't find a reliable answer to, with Google -- can my server be the reverse DNS for multiple IP addresses? Is it bad practise / wrong / asking for trouble to say my ...
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1answer
355 views

Nginx bind to external IP only (listen hostname:port)

I'd like to specify an nginx server that listens only on external IP of an hostname given in listen directive. My server has domain name foobar.example.com which resolves to public IP 1.2.3.4. When I ...
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1answer
35 views

Having multiple A records to get forward rDNS to work

Running a Droplet on DigitalOcean with Apache and a mailserver on Ubuntu. I've managed to get SPF, DKIM and DMARC working on this server, but Reverse DNS is something that I've never figured out. I ...
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1answer
216 views

PTR not showing in dig request

I am trying to set up a PTR for reverse DNS so that mail that gets sent from me scripts doesn't get blocked due to reverse DNS failure. I beleive my zone is set up correctly, however me "thinking" it'...
1
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1answer
59 views

Custom resolv.conf file

Is there any way I can specify a custom resolv.conf file (instead of /etc/resolv.conf) in RedHat Linux, similar to specifying custom hosts file via export HOSTALIASES=~/my_hosts? I don't have root ...
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0answers
16 views

Postfix not resolving rDNS - Received marked as uknown

I'm trying to configure Spamassassin to whitelist some specific servers, but it seems that it can't work until Postfix will be able to find the hostname based on the IP address. PROBLEM Postfix is ...
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1answer
110 views

ISC-DHCP-SERVER adding incorrect reverse zone entry

I have ISC-DCHP-Server and BIND9 running on Debian Stretch. I am trying to setup Dynamic DNS for my client computers, but I'm struggling with the reverse zone. Currently, when computers request an ...
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2answers
69 views

How to set up external DNS?

I have few appliances that are HTTP/HTTPS managed and assigned PUBLIC IP ADDRESSES and I need to set up DNS name resolution so I can access externally by it's name. How to set up external DNS?
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1answer
203 views

DNS is slow to resolve after force removal of a domain controller

On a Windows domain I recently had to do a "force removal" of a domain controller. I was careful to remove all the metadata and did a metadata cleanup. I also removed all references to the domain ...
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1answer
22 views

distinct mail and web hosting servers with multiple domains; spam-avoidance, PTR and SPF records

Context. I have multiple domains web services being hosted on a Digital Ocean droplet (Ubuntu and Nginx in stack). Apparently, DO automatically sets up a PTR record. However, when I query host <...
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2answers
1k views

Windows AD DNS is automatically adding PTR records for CNAMEs and I want this to stop

Preface: I am not a Windows admin. I am a Linux admin. I have a Windows 2016 server with AD DNS that handles internal DNS forward and reverse lookups. Somewhere, somehow, some process is ...
1
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1answer
196 views

Spamassassin - how to get a better score

I am testing a contact form, but I am getting a too high score for the emails sent from the contact/booking form. Here is the header: Return-Path: <yyy@host49-253-177-94.static.arubacloud.com> ...
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2answers
64 views

PTR record only visible on two public name servers

I submitted a request to an ISP (CableOne) to have a PTR record created.. 160.2.202.58 mail.huntleylaw.com I've queried 30+ Public DNS servers and I've only been able to find the PTR record on two.....
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2answers
121 views

How does MS know which public IP addresses are dynamically assigned [duplicate]

I came across this article which says that Microsoft is blocking SMTP from dynamically allocated public IP addresses. https://support.microsoft.com/en-us/help/886692/microsoft-com-now-blocks-...
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1answer
52 views

How to change the name displayed in reverse dns lookup for exchange 2011

When I run this command ping -a <some-ip> I get this result: Pinging x.y.com [ip-address] with 32 bytes of data: The IP address points to my SBS 2011 Standard. Where can I change the name x....
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1answer
579 views

Bind9 Has no NS records and Not loaded due to errors

This is my config Zone file ; ; BIND data file for local loopback interface ; $TTL 604800 @ IN SOA ubuntu. root.Lordi.local. ( 201806282 ; Serial ...
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1answer
166 views

Why does sssd break PTR records for AD-joined CentOS

I have an AD domain-joined CENTOS 7 box - call it centosbox. Whenever SSSD starts, it updates the DNS records, which is fine by me, except that it breaks the PTR records by making them point to just ...
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0answers
113 views

sub domain with url path serve on another sub domain using NGINX

https://my.domain.com is on VPS and already serving webapp with nginx+php-fpm using vestacp I want to achieve : https://my.domain.com/blog serve from http://free.hosting.xyz without showing free ...
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0answers
44 views

Running docker on a different host

I'm working on a docker image for the company web development. I have docker completely configured and running successfully. As I want to create DNS for the containers running on docker, I'd like to ...
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2answers
153 views

Postfix: forced reverse lookup for incoming connections

I see following maillog records when new mail comes to server connect from unknown [209.85.223.195] client=unknown[209.85.223.195] But that IP address is GMail IP and it has valid PTR-record which ...
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0answers
319 views

Active Directory reverse DNS zone for multiple subnets

Hi have an Active Directory domain spanning multiple subnets, for example: 192.168.1.0/24 is the main site; 192.168.10.0/24, 192.168.11.0/24, etc. are branch offices. Actually, the (AD integrated) ...
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1answer
158 views

Google cloud load balancing and reverse DNS

I have a domain example.com pointing at a Google Cloud load balancer. Requests get served by one of several Compute Engines behind the load balancer. The load balancer ip is 1.2.3.4 Now when I send ...
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0answers
42 views

Fowarding web applications according to domain name from IIS to Glassfish or Apache

I have installed three HTTP servers (IIS, Glassfish4 and Apache2.2) on a single windows-OS-based VPS. And I have three domain names (www.mysampleglass-domain.com www.mysampleapach-domain.org and www....
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1answer
77 views

nameservers reported by whois cannot be found by nslookup

The nameservers of my domain are listed correctly on the whois entry: whois destiglobal.com | grep NS gives the following result: Name Server: HEATHER.NS.CLOUDFLARE.COM Name Server: OWEN.NS....
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0answers
78 views

BIND9 reverse lookup failing for just one zone all other are working fine

BIND9 reverse lookup failing for just one zone all other are working fine. I am setting up an internal DNS server with below config. I have added reverse files for /8 networks. zone "test.com" { ...
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1answer
324 views

DNS RCODEs. Unexpected on Remote Machines

Could anyone advise on the following entries, please. What does those mean? What is mis-configured here? Please, note that it does not say "resolving errors" or something after refused and serfail. ...
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1answer
187 views

Amazon SES/Mailgun and Reverse DNS lookups for email

I am working with a client who sends out emails to clients (password reset, employee invitations, etc.) using Mailgun, but we are getting a some emails blocked due to reverse DNS lookups for the ...
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0answers
122 views

Postfix is unable to resolve IP addresses when running in chroot on Debian Stretch

I was trying to setup my own mailserver and for some reason or another postfix is unable to resolve names or IP addresses when running in chroot. I tested this on a vanilla Debian Stretch/postfix ...
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1answer
256 views

DNS issue - Windows Domain Controller 2016 - Unable to resolve public and private hosts

I have configured a Domain Controller on a Windows Server 2016 (in AWS). Before setting up the AD I can able to browse the internet. But after configured the AD I can't able to ping the computers ...
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1answer
33 views

2 Reverse DNS towards same IP. Is it bad?

We are moving our mail server to Amazon Cloud We currently have a reverse DNS for our mail server with current provider. When moving to Amazon, we have to cancel that one and get Amazon to create a ...
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2answers
2k views

Detect spammers on my server

I recently got one Undelivered Mail Returned to Sender while sending my newsletter to one of my 1500 customers. My website uses a double-opt-in procedure to make sure, the user explicitly want to ...
3
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1answer
338 views

Postfix setup with different domain name, reverse lookup and SPF

I would like to set up Postfix properly to serve multiple virtual domains while complying to all standards and being able to enable security measures like SPF. The server has the hostname server....
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1answer
1k views

How to set reverse DNS in AWS for my private nameserver?

I wanted to set rDNS for AWS for my mail server. I have created glue records, therefore my nameservers are like ns1.mydomain.com & ns2.mydomain.com. Note: My domain registrar is AWS and may ...
3
votes
1answer
811 views

sshd_config AllowUsers and IPv6

Have two servers communicating via ssh and crontab, a "master" and a "slave". Only the master can connect (execute command) on the slave. Authentication was done automatically (IPv4) thanks to ...
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3answers
2k views

Why Gmail's SMTP server Reverse lookup does not match

I am reading about setting up SMTP server and almost all articles suggest to ensure that the SMTP server's name has a matching reverse lookup (PTR) entry in DNS. However, When I casually checked the ...
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1answer
98 views

Reverse DNS issue with Mailserver (Postfix) [duplicate]

My mail server is set to server.mailtuner.com, but when i try sending to a hotmail user, it goes into the spam folder. Results on mailtester show the following reverse DNS issue: https://www.mail-...
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1answer
829 views

Protect Domain IP OVH server, DNS hosted Cloudflare, Email server Amazon SES

Domain hosted on OVH cloud. Domain hosted on Failover IP on OVH server. DNS hosted on Cloudflare. A record of domain on Cloudflare points to this Failover IP. Now I came to know that OVH puts a ...
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1answer
475 views

reverse mapping checking getaddrinfo for XXXXXX failed - POSSIBLE BREAK-IN ATTEMPT

I currently have a LAMP server running Centos 7 server on a private cloud. I have had a request from one of my clients that they would like to SFTP on to the server using a key. I have done this and ...
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1answer
71 views

Multi-view DNS PTR issues

I am seeing some problems with PTR zone resolution, and I can't quite figure out what is not configured correctly. Summary: 1) I've been delegated authority for my PTR zone (246.237.204.in-addr.arpa,...
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1answer
909 views

Automatically generating PTR records in reverse lookup zone

I am working on setting up DNS in our environment. In the test bed, I was creating some A records and PTR records in the forward and reverse lookup zone files. So, I was wondering instead of adding ...
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1answer
112 views

bind9 on server locally for mail ptr record with cloudflare as name servers

I am using cloudflare's name servers for example.com with a cname for www - these are filtered through cloudflare. In cloudflare, I have an mx record pointing to mail.example.com and a mail A record ...
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3answers
1k views

How to know if reverse PTR record is correct for emailing purposes

I send emails for test@example.com with my own server. When using dig -x xxx.xxx.xxx.xxx with the IP of my server, I get: ;; QUESTION SECTION: ;xxx.xxx.xxx.xxx.in-addr.arpa. IN PTR ;; ...
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1answer
433 views

Reverse PTR record lookup not working with dig

As mentioned here, having a Reverse PTR record is key for successful email sending and delivery from one's own server. In order to check if it's correctly set for my server, I tried: dig -x 111.111....
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1answer
258 views

BIND9 can't resolve in-addr arpa

I am trying to configure my nameservers to resolve a PTR zone for which we are authoritative. I have several forward zones that work just fine, but when I try to resolve a PTR, the result does not ...
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vote
1answer
1k views

ISC-DHCP and Bind9: DDNS update fails for reverse map (NOTAUTH)

I use the isc-dhcp-server with this configuration /etc/dhcp/dhcpd.conf: ddns-updates on; ddns-update-style interim; include "/etc/bind/rndc.key"; authoritative; zone bat. { primary localhost; key ...