Server Fault Stack Exchange
Server Fault Stack Exchange

Questions tagged [domain-name-system]

The Domain Name System, usually referred to by the acronym DNS, is a hierarchical, distributed database where the keys are domain names. Questions involving publicly accessible domains should include the real, Fully Qualified Domain Name (FQDN)

DNS is the Domain Name System, a hierarchical, distributed database where the keys are domain names.

The primary references are:

  • RFC 1034 - Domain Names - Concepts and Facilities
  • RFC 1035 - Domain Names - Implementation and Specification

These documents collectively form STD 13. RFC 2181 is a frequently cited reference for STD 13 that addresses some of the more confusing areas of operation.

The most common record types found in the DNS are:

  • "A" records - the mapping from a domain name to an IPv4 address
  • "AAAA" records - the mapping from a domain name to an IPv6 address
  • "MX" records - the mapping from a domain name to the host name of an SMTP server
  • "NS" records - used to delegate a portion of the hierarchy to specific DNS servers
  • "PTR" records - typically used (via in-addr.arpa.) to map an IPv4 address back to a domain name
  • "CNAME" records - used to alias a domain name to its canonical version

DNS packets are conventionally transported over UDP and TCP port 53. UDP is more commonly used, but larger DNS responses and zone transfers require TCP. See RFC 5966.

This Wikipedia article provides an approachable introduction to DNS.

12242 questions
4
votes
1 answer

How do I register only internal NIC address in AD DNS, with servers with multiple NICs?

I'm hosting some Windows servers on Rackspace, and have added them to a domain. Each server has two NICs, a public and private NIC. The public NIC has a public IPv4 and IPv6 address, while the private NIC has an RFC1918 address for communicating…
growse
  • 8,020
  • 13
  • 74
  • 115
4
votes
1 answer

Does the topmost DNS name, ., point to an actual server?

In the DNS system, everything stems from .. So the top-level domains like .com can also be written as .com.. For example, example.com is short for example.com.. But as I can't perform any sort of look up on . I'm wondering if it actually points to a…
Louis Waweru
  • 755
  • 1
  • 9
  • 29
4
votes
1 answer

What TLDs should I use for my NS records for redundancy? (DNSSEC support required)

Question As a general practice, is it a good idea to use multiple TLDs for the name servers? How should I choose between which TLD would be a good candidate for being the root server for my NS name? More Info I am switching over 800 DNS zones to an…
makerofthings7
  • 8,911
  • 34
  • 121
  • 197
4
votes
1 answer

Losing connectivity with DNS

I have set up an 'internal' DNS at my work, basically we have an example.com domain name that is for internet, email etc and I have created on one of our linux network servers (debian) a DNS using bind9 with the domain example.inc. So based on my…
Mike Wells
  • 71
  • 8
4
votes
1 answer

DNS Resolver White List and block all other domains

A customer asked us to put on a DNS Resolver for its network. What he requests is: A list of allowed domains (white list) that the dns resolver can answer (anche cache) Any other domains outside the whitelist must return a invalid dns record. This…
CeccoMe
  • 43
  • 4
4
votes
2 answers

Internal DNS server provide response to external requests?

I have a pfSense firewall and a Windows 2008 R2 DNS server. I'd really like my DNS server to respond to external queries for my subdomains. Right now, I'm using a 3rd party service for that. Is there a way that I can have my 2008 server respond to…
Andy
  • 195
  • 1
  • 1
  • 10
4
votes
1 answer

Using PowerShell, in Active Directory, how would I change all the DNS A records that have a given IP to a new IP?

We've been moving data centers and I have a lot of old records that were not correctly but in DNS as CNAME records, but A records that have a direct IP (e.g. 192.168.100.n) and they're all moving to a new subnet (10.19.100.n). I just need to write…
djsumdog
  • 1,100
  • 2
  • 16
  • 29
4
votes
1 answer

SCOM 2012 DNS Forwarder Availability Monitor

Background: I have an environment with two different AD domains, each in its own forest, each with two Windows Server 2008 R2 domain controllers acting as DNS servers. There is no trust between the domains. Each DNS server manages the main DNS zone…
Massimo
  • 70,200
  • 57
  • 200
  • 323
4
votes
1 answer

Does DKIM works with subdomains?

ISP's recommend you segment your marketing and transactional emails by using different IPs. I want to start using DKIM, but since DKIM is a domain based reputation system I wonder if signing with the same company.com domain will impact the…
Feelsgoodman
  • 43
  • 2
4
votes
2 answers

Protocol (or service publish/discovery) to detect devices in network

we connect some embedded devices in a network. What i am looking for now, is a way to find the devices IP and identify them. We work with Windows PC´s and i am about to write a C# tool that should do this. I thought about send a udp broadcast and…
Gobliins
  • 201
  • 4
  • 11
4
votes
1 answer

What are the consequences of giving an AD domain differing NetBIOS and DNS names?

In the past, when creating AD domains, I've used the common convention of using a sub-domain of the company's publicly registered domain name, e.g "corp.mycompany.com" or "int.mycompany.com". I've always accepted the default NetBIOS name when…
dbr
  • 1,852
  • 3
  • 23
  • 38
4
votes
1 answer

Can a DNS wildcard only be the leftmost part of a record?

I'm using TinyDNS, and have successfully used wildcard records of the form: +*.: (+ for A records.) Can I also use: +development.*.: ? My intention is for all subdomains to have their development website point to our dev…
Iain Hallam
  • 447
  • 2
  • 6
  • 22
4
votes
1 answer

How to prevent down time if domain registrar goes down?

incase you didn't know, godaddy has just been hit by some idiot hacker that has caused millions (including my own) sites to go down. This leads me to my question... I was using the godaddy nameservers (NS12.DOMAINCONTROL and NS13.DOMAINCONTROL.COM)…
jon
  • 145
  • 1
  • 1
  • 5
4
votes
2 answers

Primary DNS server removed, can I change secondary to primary?

The primary server had DNS accidentally removed. Now the secondary server can not load the zone. Can I switch the secondary server from a secondary zone to a primary zone? Secondary is NT3 and primary is Windows 2003. This is not AD integrated.
rtf
  • 884
  • 2
  • 17
  • 31
4
votes
2 answers

Global Reverse DNS look-ups not working

I am moving from an old server to a new one and everything went well until I got to the DNS server. I cannot get the reverse look-up to work. I cannot find any misconfiguration but I'm not an expert. rDNS locally works but from other Inet hosts it…
Schoors
  • 41
  • 2
1 2 3
…
99 100