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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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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131 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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151 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
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Are PTR records added only by the ISPs that provide and manage the IPs?

I am administering a network with many locations and work with multiple providers I checked out with my DNS provider to change the PTR records for one of the IPs, they replied: Dear Sir, We ...
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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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49 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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2answers
212 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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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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108 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
1k 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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61 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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55 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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721 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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206 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
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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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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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4answers
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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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928 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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354 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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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
357 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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467 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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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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169 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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494 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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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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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
76 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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1answer
93 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 ...
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2answers
238 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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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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170 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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290 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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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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112 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, ...
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120 views

Reverse DNS lookup not resolving correctly

I've been searching and searching for the answer and I can't find it. My problem is that all of my emails sent from my server are either going to spam folders or not being delivered. I am trying to ...
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3answers
425 views

Are generic reverse DNS entries acceptable for an outgoing SMTP server?

Our PTR records are managed by our ISP, as our ranges are too small for them to consider delegating to us. So, every time I want to update an entry, I have to email their support team. In an effort ...
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rDNS entry on a separate name server from forward dns - is this okay?

Our reverse DNS lookup is delegated to our name server (ns.example1.com) by AT&T, who leases us our IP address (1.2.3.4) and our forward DNS lookups were on the same name server (ns.example1.com). ...
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593 views

delegating /24 and /64 reverse zones

I'm sure I'm overlooking something so simple, but I'm just not seeing it... I'm trying to delegate the /24 and /64 reverse zones for our Test network to hosts within the Test network. I'm seeing the ...
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146 views

rDNS setup to prevent emails appearing as spam / phishing messages

We are trying to send email without the email appearing in the spam folder. The emails that we are sending is solicited bulk email. The main problem is that the emails are appearing as phishing ...
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1answer
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Domain names have gone down - site still up [closed]

I host a couple of websites on the same Ubuntu server, and as of today both domain names have gone down. PuTTY and FTP still both work so it is obviously a problem with the domain name. I haven't ...
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3answers
757 views

Does changing the Primary DNS Suffix of a Windows Server 2012 machine require a reboot?

My server has the following IP Addresses: 127.0.0.1 192.168.100.103 208.nnn.nnn.180 199.nnn.nnn.29 It's FQDN is mymachine.example.com. However, calling ...
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1answer
2k views

Cloudflare, reverse DNS and php mail ending up in spam folder

I've been using Cloudflare to host my DNS, and PHPMailer to send e-mail through ZOHOs SMTP servers with great success, but have found that all my e-mails are hitting Gmail, Zoho and Hotmails spam ...
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151 views

What is the structure of zones synthesized by BIND's empty-zones-enable feature?

BIND 9.4.1 implemented automatic empty reverse zones for private address space in order to prevent reverse DNS leakage. This saves an administrator the trouble of having to define these empty zones, ...
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175 views

Configuring bind with reverse DNS in external server

I'm having troubles configuring BIND with the reverse DNS being made by an external server in the hosting company. Lets assume i have a domain "server.com" that should contain 2 nameservers: ...
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336 views

SSH to a server with multiple reverse DNS entries [duplicate]

While SSHing into my server with an RSA key, I get this message: Address 255.100.236.105 1 maps to a1.example.com, but this does not map back to the address - POSSIBLE BREAK-IN ATTEMPT! Even ...
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1k views

Reverse DNS and Godaddy email server, What should it point to?

We are assigned 3 static IP addresses by our ISP and lately we have been having problems delivering our mail. We checked with Cloudmark and they suggested contacting our ISP to add a reverse DNS entry ...
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Reverse dns returns a different host each time

So, randomly I happened to ping abc.com and found this fascinating: $ ping abc.com PING abc.com (199.181.132.250) 56(84) bytes of data. 64 bytes from m.abc.com (199.181.132.250): icmp_req=1 ttl=237 ...
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How do providers plan to deal with rDNS for client /64 IPv6 blocks when assigned?

The standard block assigned to a home will be a /64 block to enable autoconfigure. This means the traditional reverse DNS mapping of host-237.miami.ispname.com is not only practical, it's improbable ...
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652 views

How to force an ISP to remove false reverse DNS?

There is an IPv4 address (in a /8 managed by ARIN) that I have no control over which reverse resolves to a domain name which I registered. Someone used the IP address to run a scam, and it is ...