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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Can I Run My Web Service and DNS Service on the Same Server?

I am quite new about Linux. I wonder if I could run DNS and Web Server on the same server? The reason is I have a server which they want me to set it up as a DNS & RevDNS server with the ...
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2answers
51 views

Reverse DNS while using Azure Resource Manager

I am very much aware that Reverse DNS is possible on Azure Cloud Services. That's not what I'm asking about. I need to know if it's possible when using Azure Resource Manager. I've looked around a ...
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1answer
26 views

Roots server do not update my new nameserver (CentOS bind DNS server)

Last week, I changed my dns nameserver from dns2.applistar.com to ns1.applistar.com. But after that, my DNS server was downed. I do not know why :(. I reconfig everything, but it still downed. I ...
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3answers
68 views

Reverse DNS does not match SMTP Banner [duplicate]

I'm new to this site but I have found many good answers on this site before. I have also searched for my actual question but I didn't found the answer or at least I didn't understand what should I do ...
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1answer
59 views

PTR record format for IPv6

What is the difference in the following two IPv6 PTR formats? 4.3.0.0.0.0.0.0.0.0.0.0.0.0.0.0 IN PTR smtp.example.com. ...
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1answer
36 views

Configuring rDNS and PTR Record [duplicate]

I know that here was a few questions about it, but they didn't answer my question. Here is my issue. I have a mailserver on my dedicated server with full access. In robots I wrote down these lines of ...
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1answer
30 views

How do I create rDNS (Reverse DNS)

How to create rDNS (Reverse DNS), I am using Centos 7.0 and I need to create rDNS for 50 IP's and domain. Can you please guide me how can I create. Example. Example.com - xxx.xxx.xxx.xx0 ...
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1answer
44 views

“Bad PTR DNS Resource Record” when sending E-Mail from Shared Hosting

I have a virtual server with one IP x and have multiple sites a.com and b.com running on it. When accessing x in the browser, I get to homepage a.com. Sending an e-mail from a.com to GMX is without ...
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1answer
25 views

How to redirect MX records to origin domain name?

For a home setup I only have 1 public IPv4. So I have to use it for all my hosts. Luckily I have only one. So in the DNS I use the at sign @ to define the origin, example.com with an A record where I ...
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1answer
21 views

hMailServer and reverse DNS

I have an hMailServer installation on a Windows 2012 server VM and need to properly set up reverse DNS + the mail server in order to avoid getting e-mails bounced back from certain big providers, ...
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2answers
39 views

How reliable is validating email domain by reverse DNS MX record checking [duplicate]

This question is not about how to protect against spam or validate a particular email user. But how reliable is validating emails domain (does it exists at all) by reverse dns. What are the pitfalls ...
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0answers
23 views

ipv6 rDNS with bind

Maybe I just can't wrap my head around ipv6 yet but I'm having trouble returning DNS entries for rDNS. Considering the ipv4 scheme, the following is what I'm aiming for: internal.example.com should ...
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1answer
30 views

Make BIND DNS server to “remember” the resolved names

I have a corporative VPN server where every client request (the IP address of the server they are accessing) are being logged via an script with tcpdump. However, the logs are not really useful ...
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2answers
25 views

Reverse DNS Record when MX record (Original.com) to move to other places (that ip range is another domain name like another.com)

I'm recently moved the email server from Company branch A to Company branch B. Branch A company is using original.com and branch B is using another.com Scenario: Branch A Original.com ( 192.0.0.1 ...
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3answers
73 views

Reverse DNS is not working

I got a mail server that can't send outbound because I don't have my reverse dns entries correct. Admittedly at first I knew it wasn't configured properly but from every single example I could find on ...
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1answer
56 views

Centos 7 DNS Server /PTR/IN' **denied**

I need help, i've spend some time to troubleshoot the dns server that i created. but what happend is: when i tried to resolve the address i receive below log: Nov 15 04:21:01 mydnshostname00 ...
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1answer
33 views

some emails do not send because wrong IP of destination mailserver

in my postfix log files I found a strange thing. some domains resolve always to the same one IP address, but not every time. Just sometimes. Oct 28 14:51:46 maxi postfix/smtp[4057]: 5628514640F0: ...
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2answers
54 views

WARNING: At least one of your NS name does not seem a valid host name

So here is the issue I am having. When I run a DNS check on my TLD I am getting conflicting results. The domain name is newage.design and my NameServers are NS1.newage.design, NS2.newage.design, and ...
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1answer
26 views

Use ip address for name server and have it dedicated to a single site

Ok so I think I have this setup right but I just want to be sure. I have 3 IP address: 1.1.1.1 also known as ns1 2.2.2.2 also known as ns2 3.3.3.3 also known as ns3 They are being used as ...
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0answers
64 views

Curl Error Connection timed out

I have a website (www.example.com | 123.456.789), in that machine i only have 1 web app running. i am trying to use php file_get_content() to a file which in my own server (located on some file like ...
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1answer
55 views

DNS Active Directory Zone Replication Scope (Forest vs Domain)

When I create a new Domain Controller with dcpromo then the wizard will also add a DNS Role to the server because the first domain controller must be the global catalog server for the forest. After ...
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1answer
27 views

DC Promo With DNS Windows 2008R2 Resulting In Weird Network Error

I am preparing for DC domain migration in which I am encounter some error that I had never encounter in my VM testing environment. Note: This is the first time I am setting up an active DC with DNS. ...
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1answer
43 views

Mail and Webserver on single Host, Reverse DNS not matching

I have a vServer from Server4You and installed a mailserver with postfix, dovecot and slapd for authentification, my problem is: All the emails send from the server to outlook or gmail land in the ...
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1answer
35 views

Postfix/Spamassassin can't determine rDNS too often

I am running a Debian 7.9 server with Postfix 2.9.6 and Spamassassin 3.3.2. One of the standard checks Spamassassin does, is to check for a rDNS record. I am assuming that it gets that info from the ...
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0answers
33 views

Reverse DNS for 172.* [closed]

Our private network is a large 172.* with many subnets. I'd like to have one DNS server for the whole deal if possible. I have this working in the forward direction but not in the reverse. Bind9 on ...
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1answer
621 views

Delivered to internal network by a host with no rDNS

Recently our emails started going to spam for recipients at Gmail and Yahoo mail. I ran a SpamAssassin test, and have found the following: pts rule name description 0.0 ...
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1answer
77 views

How do I find the actual domain for an IP addresses in my web log that uses a CDN?

I'm trying to analyze our web access log to report on which organizations are accessing our website. But for many of the IP addresses in the log, the reverse DNS lookup resolves to CDN domain names ...
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1answer
572 views

Linux PCs sending “ICMP udp port unreachable” to DNS server

So digging around in my syslog I have been noticing a lot of ICMP packets being flagged by our ASAs: %ASA-4-313005: No matching connection for ICMP error message: icmp src Internet:x.x.21.122 dst ...
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2answers
434 views

Is it valid to have several IP addresses resolving back (PTR) to one name that doesn't match either of the relevant A records?

I have several devices, each with its own IP address. There are various names pointing to these addresses (in several different domains). As an example the device with IP address 10.0.0.1 is known ...
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1answer
54 views

reverse dns configuration not working

I am configuring my reverse dns server, after installation then I run the following: nslookup 110.74.133.89 Server: 192.168.101.4 Address: 192.168.101.4#53 ** server can't find ...
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2answers
183 views

multiple ptr record in bind

I'm running some small ISP here and I own couple of IP ranges. I have given a few public IP addresses to some of my customer and they are running mail servers on them. They have demanded me to add ...
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2answers
2k views

Reverse DNS is not a valid hostname [closed]

I help a friend run a server, which includes a mail server. http://mxtoolbox.com reports that our reverse DNS is not a valid hostname. The reverse DNS currently points to domain.com. Should it point ...
2
votes
1answer
2k views

Reverse DNS is not a valid Hostname error from MXToolBox

I can't send email messages from my server. However, I can receive email messages. I set up my server the exact same way I did many times which I've proven it works and it's pretty straightforward and ...
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0answers
44 views

dnsmasq classless reverse forwarding

I'm currently using a dnsmasq as DNS forwarder for a handful of classless zones and the A record forward is working fine. But I now do have some trouble with the PTR query forwarding, since I don't ...
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1answer
92 views

Public domains and hosts resolving to 127.0.0.1

Our security systems are going crazy alerting us that hundreds of external DNS queries and responses are resolving to addresses like 127.0.0.1 and sometimes 0.0.0.0 to requests originating from our ...
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1answer
92 views

Reverse DNS query of public IP returns localhost

I'm seeing this unusual behavior with reverse DNS lookups on this public IP Address: 222.253.228.79. Can someone explain what's going on? MXToolbox PTR lookup resolved localhost as the domain ...
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0answers
98 views

exim4 mail relay for multiple domains

I have hMailServer running on a Windows 2012 box and exim4 running on a separate box. However, I would like to continue configuring my email accounts on the Windows server (via hMailServer), but relay ...
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2answers
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Reverse IP Lookups [closed]

When I resolve google.com I get the following ip addresses Name: google.com Addresses: 2607:f8b0:4006:80b::1006 173.194.123.6 173.194.123.0 173.194.123.8 e.t.c However ...
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0answers
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Why does my box keep sending reverse DNS queries and how to stop it?

Situation My box keeps sending reverse DNS queries about our LAN hosts. Obviously they all fail because they are private addresses. Request Source: 192.168.1.6 Destination: 192.168.1.1 (default ...
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1answer
54 views

How to map subdomain to a domain with CNAME?

I would like to point CNAME records for www.example.com to sub.example2.com. The hosting for example2.com is a shared hosting (cPanel without Addon domain feature). So, what I did was to add a ...
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1answer
82 views

nslookup how to get list of domains in a DNS server

I want to list all domains In a DNS Server. More details: spouse that foo.com is a web hosting company and ns1.foo.com is their DNS server. the web sites foo1.com to foo100.com are hosted by this ...
2
votes
2answers
55 views

Removing DNS entries

I've got the following DNS records and I would like to ask if it is OK/safe to remove the unwanted entries: admin/ftp/m/mail/webmail (I hope the mail one doesn't affect the emails?) @ IN NS ...
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1answer
49 views

Syslog-ng reverse dns lookup for data fields

I would like to try a reverse-dns before storing the firewall logs. I know this is possibile in logstash but i don't know if syslog-ng can be configured to do the same. Actually my logs coming from ...
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2answers
234 views

What should my reverse DNS be for my inhouse email server?

So I have an inhouse exchange server for the domain visaustralia.com. (email addresses are email@visaustralia.com) And when checking the reverse DNS of my static IP address with ...
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0answers
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Mailserver complains about reverse DNS lookup on my Gateway

I am presented a mail server setup, that is working well. There's only a small issue, which makes me think, there's something wrong in the DNS setup. It is a small setup with a Debian mail server ...
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0answers
108 views

Windows DHCP server not discarding PTR records when an address is leased

Got the following setup regarding DHCP & DNS: Windows Server 2003 doing DHCP Windows DNS (different server)authoritative for the forward zone BIND DNS (on a UNIX server) authoritative for the ...
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2answers
254 views

rDNS 'zone [xxx] has no address record (A or AAAA)

teaching myself some server tricks. Getting trouble with bind9 on debian8. named-checkzone pro.lan db.pro.lan.inv zone pro.lan/IN: NS 'server.pro.lan' has no address records (A or AAAA) my ...
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1answer
119 views

rDNS and forward DNS for mail server behind firewall, different IPs

All, Here is my setup : Firewall(x.x.x.114) <--> mail.mailserver.com (FQDN) (x.x.x.118) When sending mail, header has following IP ...."Receivedfrom mail.mailserver.com ([x.x.x.114])", my ...
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1answer
133 views

Not able to load reverse zone with bind

I've created a simple bind dns server to host 3 zones in a test lab. bath.local (192.168.100.0/24) munich.local (192.168.101.0/24) dhcp.local (192.168.99.0/24) I want forward and reverse ...
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1answer
2k views

Reverse DNS does not contain the hostname error from MXToolBox

I am not sure where I have gone wrong in my configuration but I am getting the error Reverse DNS does not contain the hostname for my domain sparkdojo.com I had the hosting company set the PTR record ...