DNS Lookup

DNS (Domain Name System) is a hierarchical and decentralized naming system for computers, services, or other resources connected to the Internet or a private network. It is responsible for translating human-readable domain names into numerical IP addresses, and vice versa.

DNS operates on a client-server model, where clients, such as a web browser or email client, initiate requests to resolve domain names to IP addresses. The requests are sent to a local DNS server, which either resolves the domain name to an IP address or forwards the request to another DNS server closer to the authoritative server for the domain.

The authoritative server for a domain maintains the DNS records for the domain, including information such as the IP addresses of the domain's web and mail servers, and the server responsible for resolving any subdomains of the domain.

DNS allows the Internet to be easily navigated by humans, while also providing a scalable and flexible infrastructure for the resolution of domain names to IP addresses, enabling the smooth operation of the Internet and the resources it connects.

DNS (Domain Name System) lookup is the process of resolving a domain name to an IP address. It is an essential component of the Internet, allowing human-readable domain names to be translated into numerical IP addresses that computers use to communicate with each other. During a DNS lookup, a DNS resolver queries a series of DNS servers to determine the IP address associated with a specific domain name. The result of the DNS lookup is then cached for a specified amount of time to speed up subsequent requests to the same domain. There are many records in the DNS, including A, AAAA, CNAME, MX, NS, PTR, SRV, SOA, TXT, CAA, DS, DNSKEY, and many others.

Here are the steps involved in a DNS lookup:

• Query: A client, such as a web browser, issues a DNS query for a specific domain name, for example "www.example.com".
• Recursive Query: The client's local DNS resolver, often provided by an ISP, receives the query and checks its cache for a recent and valid response. If not found, it will initiate a recursive query to other DNS servers.
• Root Server: If the local DNS resolver does not have the answer, it starts by querying the root DNS servers for the top-level domain (TLD) of the domain name. For example, for "www.example.com", it will look up the TLD ".com".
• TLD Server: The root servers respond with the IP addresses of the TLD servers responsible for the TLD in question. The local DNS resolver then queries these TLD servers.
• Authoritative Server: The TLD servers respond with the IP addresses of the authoritative DNS servers for the specific domain name. The local DNS resolver then queries these authoritative servers for the final answer.
• Response: The authoritative servers return the IP address associated with the domain name to the local DNS resolver.
• Cache: The local DNS resolver caches the response for a specified time, called the Time To Live (TTL), to speed up subsequent requests for the same domain name.
• Return: The local DNS resolver returns the IP address to the client, allowing it to connect to the target server and load the requested web page or resource.

Here are the steps involved in a DNS lookup:

• Recursive Query: Also known as a "full query", this type of query is initiated by a DNS client and requires the DNS server to fully resolve a domain name to an IP address. The DNS server will perform any necessary additional queries to other DNS servers to retrieve the necessary information, and then return the result to the client.
• Iterative Query: Also known as a "partial query", this type of query is initiated by a DNS client and only requires the DNS server to return the best answer it has available. If the DNS server does not have the complete information, it will return a referral to another DNS server that may have the information. The client will then initiate another query to the referred server to retrieve the complete information.

Both recursive and iterative queries are used in different situations, with recursive queries being more common for end-user clients and iterative queries being more common for DNS servers. The choice of query type depends on the specific requirements of the DNS client and the capabilities of the DNS server.

DNS records are the individual entries in a DNS zone file that provide information about a domain name and its associated resources. There are several different types of DNS records, including:

• A (Address) record: The A record maps a hostname to an IPv4 address, allowing a domain name to be resolved to an IP address.
• AAAA (Address) record: The AAAA record maps a hostname to an IPv6 address, allowing a domain name to be resolved to an IP address for IPv6-enabled hosts.
• MX (Mail Exchange) record: The MX record specifies the mail server for a domain, allowing email to be delivered to the correct server for the recipient's domain.
• NS (Name Server) record: The NS record specifies the authoritative DNS server for a domain, providing the information necessary for other DNS servers to resolve domain names to IP addresses.
• CNAME (Canonical Name) record: The CNAME record maps an alias domain name to its real, or "canonical", domain name, allowing multiple domain names to point to the same IP address.
• TXT (Text) record: The TXT record allows you to associate text-based information with a domain name, such as SPF records or human-readable information.
• SRV (Service) record: The SRV record provides information about available services for a domain, such as the location of a specific server for a particular service.
• PTR (Pointer) record: The PTR record maps an IP address to a hostname, allowing IP addresses to be resolved to domain names. PTR records are used for reverse DNS lookups.
• SOA (Start of Authority) record: The SOA record provides information about a domain and the authoritative DNS server for that domain, including information such as the primary nameserver and responsible person, serial number, and refresh and retry intervals.

Each type of DNS record serves a specific purpose and is used in different ways to support the resolution of domain names to IP addresses and the associated resources for a domain.

DNS records are the individual entries in a DNS zone file that provide information about a domain name and its associated resources. There are several different types of DNS records, including:

• Choose a DNS lookup tool: There are many DNS lookup tools available, both online and as standalone applications, that can be used to perform DNS lookups. But mojha.com is a the most popular tool for DNS lookup.
• Enter the domain name: In the tool, you'll typically need to enter the domain name that you want to look up. This can be a fully qualified domain name (FQDN) such as "example.com" or a subdomain such as "www.example.com".
• Choose the type of record: Depending on the tool, you may be able to specify the type of DNS record you want to look up. Common record types include A, MX, and NS.
• Perform the lookup: Once you have entered the domain name and any other relevant information, you can initiate the lookup. The tool will then query the DNS servers to retrieve the requested information, which will be displayed in the tool's output.
• Analyze the results: The output of the lookup will typically include information such as the IP address associated with the domain name, the authoritative DNS server for the domain, and any other relevant information, depending on the type of record requested. You can use this information to diagnose issues with domain name resolution, or to simply learn more about the domain and its associated resources.