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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.

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

Computer networks use the Domain Name System to determine the IP address associated with a domain name. This process is also known as forward DNS resolution. Reverse DNS lookup is the inverse process, the resolution of an IP address to its designated domain name.

Source: Wikipedia.

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Disable reverse lookup in rsync daemon

I'm having an issue with some rsync modules being served through rsync --daemon This lines are from my /var/log/rsyncd.log file : 2013/02/08 12:15:28 [13174] name lookup failed for XXX.XXX.XXX.XXX: Name or service not known 2013/02/08 12:15:28…
Jorge V.
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sshd warning, "POSSIBLE BREAK-IN ATTEMPT!" for failed reverse DNS

Whenever I SSH somewhere I get something like this in the logs: sshd[16734]: reverse mapping checking getaddrinfo for 1.2.3.4.crummyisp.net [1.2.3.4] failed - POSSIBLE BREAK-IN ATTEMPT! And it is right: if I do host 1.2.3.4 it returns…
rking
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Finding all domain names that resolve to the same ip?

Lately I've been tracking a spammer on craigslist. I recently discovered that he's added a new technique to his arsenal, he registered a whole bunch of domain names but they all resolve to the same ip address. Is there any way to take an ip address…
Janak
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How are DNS PTR records managed?

As I understand it, an IP address-owner can set up a DNS PTR record for his IP address to map the IP addresses to its host names. There are some things about this I don’t understand. I’ve managed other DNS records often using web based interfaces,…
Martin
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how to add a REverse PTR Record on Amazon Route 53?

if i have the below ip 168.144.254.X and i would like to add a ptr record in amazon in the form of X.254.144.168.in-addr.arpa what should be in the name field and what should be in the value field i have a zone created with a name like mydomain.com…
Oscar Cabrero
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Reverse DNS Lookup for 10.* Failing

I am trying to configure NSD and Unbound to handle Internal DNS. I have everything working for forward look ups but reverse looks ups are failing. I am not sure what to do next, but looking at the dig (reverse) response, it has something to do with…
Adz
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How to configure bind9 to be a local DNS only with no internet access?

I want to configure bind9 to be a local DNS only with no internet access at all. So I have 5 PCs in my virtual domain xy.com. Within this domain there is no access to the internet. The DNS server has entries like: pc1.xy.com IN A…
JohnnyFromBF
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Should every IP address be reverse and forward resolvable?

Will there be trouble if non-server machines: 1. don't have forward addresses that match in-addr.arpa? 2. don't have forward addresses? 3. don't have in-addr.arpa PTRs?
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Disable DNS Caching PHP

I need to get the latest A records of a DNS in a script. The script is doing some monitoring operations. The Default TTL of DNS record is 5 minutes, but the monitoring script is running every minute. I am using PHP's function dns_get_record to get…
Sparsh Gupta
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SMTP host name vs. domain in "From:" address vis-a-vis Email Deliverability

I'm trying to implement (or make sure that I'm correctly following) email sending best practices to improve deliverability, but the role of the smtp server's host name vs the domain name of the From: email address seems to be unclear, even after…
Jared Duncan
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SSH reverse DNS lookup

I was wondering why I'm connection to a server with SSH, it does a reverse DNS lookup on the IP of the remote server. I have found comments telling that it was for security reason, lots of tutorial showing how to disable it but no explanation. Thank…
Martin Trigaux
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Decisions about DNS on IPv6

We are rolling out IPv6, and I'm thinking about our DNS strategy. This is not a technical question--it's more of a "best practice" question. We have Active Directory internally, and the domain controllers handle both the authoritative DNS for our…
theglossy1
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Reverse DNS/bind named-checkzone "zone NS has no address records (A or AAAA) error"

This is my reverse dns file. $TTL 1D @ IN SOA dns.prv.server.co.uk. root.prv.server.co.uk. ( 2014090402 ; serial 3600 ; refresh …
neilH
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MXToolbox: "Reverse DNS is not a valid Hostname"

I know that there is another thread about this topic here on serverfault.com but it did not solve my issue. I have also googled it and it seems that SPF record could be mis-configured in some cases but it did not help me neither. Can someone tell…
Jens Kirk
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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 to host2.sparkdojo.com and all of the tests I…
CodeKing
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