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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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
22 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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0answers
25 views

Reverse lookups not working [closed]

hehe, I up-voted the previous answer before doing some fettling myself. Right, so, if you edit your named.conf and add the following: zone "newdomain.com" { type forward; forward only; ...
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1answer
38 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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1answer
21 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 ...
1
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0answers
20 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?
2
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1answer
23 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: ...
0
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2answers
98 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
54 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 ...
0
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1answer
49 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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1answer
48 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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2answers
38 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
60 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 ...
0
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1answer
93 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
34 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
50 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
85 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
95 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. ...
2
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2answers
156 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
36 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
91 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... ...
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1answer
66 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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0answers
40 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 ...
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2answers
104 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
354 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
61 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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103 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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1answer
129 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
59 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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1answer
91 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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0answers
58 views

Disable glusterFS reverse lookup for hosts

I have set up a distributed GlusterFS volume on 3 bricks. However, since a network issue site-wide, one of the servers is unable to start glusterd. The reason is because the reverse DNS lookup gives ...
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3answers
155 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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1answer
46 views

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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0answers
194 views

The HELO/EHLO string doesn't match to one of the names in the rDNS from connecting IP

I have a website that uses Postfix to send out emails. It turns out the IP address for my site has been blacklisted, and testing here: http://multirbl.valli.org/, by sending out an email results in ...
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2answers
215 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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26 views

Overriding specific RDNS requests

I use /etc/hosts to override a few dns queries: 192.168.1.100 wug.me However, this doesn't seem to affect the rdns entries: wug@desktop:~$ host wug.me Host wug.me not found: 3(NXDOMAIN) Using ...
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1answer
91 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
65 views

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 ...
0
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3answers
415 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
756 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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0answers
90 views

SenderBase not detecting hostname or domain for my IP

Two months ago I've purchased a VPS with DirectAdmin and CentOS but since then I've been receiving this reject message while sending to a certain ISP: 554 Your access to this mail system has been ...
0
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1answer
69 views

What is the default format of replies from BIND's built-in reverse zones?

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, ...
0
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1answer
86 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: ...
0
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1answer
113 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 ...
0
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1answer
529 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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3answers
74 views

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 ...
2
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1answer
62 views

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 ...
12
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1answer
374 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 ...
0
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1answer
105 views

Multi-IP server: how do programs know which IP to use?

I recently tried adding second IP address to our server for various reasons and found that now when I check netstat -anob there are many programs/services listening and establishing connections to ...
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1answer
88 views

Spam issue - outgoing mail server

Our previous developer wrote a basic aspx contact form for one of our hotel clients before leaving, all has been fine with it so far but when testing this week I noticed that although the email sent ...