DNS - Domain Name System
DNS Definition
DNS automatically converts the names we type in our Web browser address bar to the IP addresses of Web servers hosting those sites.
Introduction to the Domain Name System (DNS)
The DNS maintains a distributed, hierarchical database of name and IP address data that is widely used on the Internet. Much of DNS functions happen automatically although some initial setup must be done to enable network devices for DNS. Learn about the DNS name space, root servers, resolvers and other essential aspects of DNS technology.
What Is a DNS Server?
A DNS server is a special type of computer on the Internet used to support the Domain Name System. Numerous DNS servers across the Internet maintain a distributed database of domain names and IP addresses.
Top Free Internet DNS Servers
Internet providers maintain free DNS servers open to the public. Setting up one of these free DNS options on your network can improve your Internet performance.
Internet Domain Extensions
Domain extensions on the Internet are often called top level domains (TLDs). Dot-com (.com) is the most commonly used top-level domain extension on the Internet. Many others exist, however.
IP Lookup - Forward and Reverse Address Lookup
Several Internet services and network utilities including DNS support lookup of Internet Protocol (IP) addresses. Forward IP lookup converts a server or domain name to an address. Reverse IP address lookup converts the number to the name.
ipconfig - Windows Command Line Utility
ipconfig is a command line utility that allows you to manage the DNS and IP address information of a Microsoft Windows computer.
nslookup
nslookup is a troubleshooting tool used to obtain information about Internet servers. As its name suggests, nslookup finds name server information for domains by querying DNS. The command line version nslookup.exe can query DNS servers for IP address (A), mail server (NX) and other DNS records. Wed-based variants of nslookup may support...
Check IP Addresses on DNS Blacklists
One way to confirm whether email or other messages you're receiving are spam is to check its originating IP address against one of the public DNS blacklist - DNSBL - databases available online.
DNS Caches and Cache Poisoning
A DNS cache is a small database maintained by a computer's operating system. The database contains records of all recently accessed Internet domains.
Why There Are Only 13 DNS Root Name Servers
For a network as large as the Internet, it seems quite surprising that only 13 servers would be responsible for directing all of its traffic. The situation isn't quite so simple.
What Is DNS Poisoning?
Poisoning a DNS server occurs when hackers alter the DNS records for a specific domain, redirecting unsuspecting users to a different Web site than the authentic one.
DDNS - Dynamic DNS
Unlike DNS that only works with static IP addresses, DDNS works with dynamic IP addresses, such as those assigned by an ISP or other DHCP server.
How to Set Up a DNS Alias using Apache Web Server
Follow these instructions to set up multiple Web domains to reference separate directories on your Apache Web server.