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Our Find DNS records tool lets you query all of the available DNS records on a domain. DNS, or Domain Name System, is a protocol that is used on a globally distributed network of DNS servers to look up information on Internet domain names.
If you are having problems with resolving domain names, you can Find DNS records to troubleshoot the problem. If you can't fix the problem yourself, Find DNS records to track down email addresses of administrators who are directly responsible for taking care of problems on their DNS systems. You can also use our tool to discover IP addresses that may let you make direct connections to hosts.
To Find DNS records, simply enter the domain name or a URL into the text box and enter the CAPTCHA. (If you run into a particularly difficult CAPTCHA, press the refresh button for another one.) After entering the CAPTCHA, press the enter key or click on the Submit button. Our application will query the DNS system and retrieve the available DNS records for the domain.
On a fundamental level, the DNS database is composed of many types of records, called RRs, which are stored on DNS servers. An RR is a collection of data variables, each with a different meaning. Perhaps the most important type of RR is the type that contains host IP addresses, which allow establishing Internet communications with a domain. The process of looking up an IP address for a domain is called name resolution.
It is rare to find a single DNS server that contains every record for every domain, and no DNS server is an authority on every domain. Instead, DNS servers contain records that point to other nameservers that they query to resolve domains outside of their zones. When you make a request to a nameserver, it looks to see if it has the requested information in its "zone file," the part of the DNS database that it keeps on hand at all times. If it has the information in its zone, it will return it to you directly. If not, it will make recursive calls to other DNS servers to find the information.
If the DNS server does not have the information in its zone, it will next look to see if it has the information in its cache. If it has the information in its cache, it will send it back to you without contacting other DNS servers.
If it doesn't have the domain information in its zone and doesn't find it in its cache either, it will query other nameservers to find up-to-date information on the domain. The nameservers that it contacts may contact other nameservers through a process called recursion. Once a nameserver has retrieved the requested records from other nameservers, it will return the query results and cache the records to speed up future requests.
Cached records do not stay on nameservers forever. They contain a value called TTL or Time to Live. It is a timer that decreases by one every time a second passes. When a cached DNS record's TTL value expires, it will no longer be retrieved from the cache. Instead, the DNS server will retrieve fresh records if requested.
The host variable specifies the fully-qualified domain name to which the record is attached. It is sometimes referred to as the NAME variable.
The CLASS variable specifies the namespace for the record. This is almost always IN for Internet. Two other obscure classes exist: The first, Chaos, was used to support a communications protocol used by LISP machines. The second, Hesiod, is a database protocol used on an 80s platform called Project Athena. Neither is in common use today, so it is highly likely that all CLASS variables you encounter will have the value IN.
The TTL variable specifies the time in seconds left until the record expires.
The type variable is the record type. Many record types exist. Some of the most common include:
According to the DNS specification, the primary master server should be named by the MNAME variable. If the MNAME variable contains the domain name, that is a serious error unless the zone name resolves to the address of the primary master.
The RNAME variable contains the email address or an email alias of the person who is responsible for the zone. The "@" sign in the email address is represented instead as a period. If you have issues with the zone or if you find errors, you should be able to find a contact address for the zone administrator here.
The TARGET variable points to a server that can be looked up using the record. If the record is an MX record, the server will be a mail server. If it is an NS record, the server will be a name server.
The SERIAL variable is the serial number of the zone. Whenever any modification is made to the zone, the serial number is increased to a larger number. Many zone administrators use the SERIAL variable to represent the date of the last zone update.
The REFRESH and RETRY variables are used to configure how often the secondary DNS servers query the primary master server for new and changed records. Modern DNS servers don't need to have these set to low values to keep up to date because the primary master server can push updates to the secondary servers.
The EXPIRE variable specifies how long the zone records can remain valid. The life of cached DNS records can be extended if the authoritative DNS server for a domain goes offline, but they cannot be extended past the expire value.
The MINIMUM-TTL variable is the default value for the TTL variable record requests on the zone. A high MINIMIM-TTL value can make it so changes on the primary master are not reflected by all DNS servers for an extended period of time.
The PRI variable specifies the priority of a mail server. The lower the PRI value, the higher the priority. Usually, the domain mail server record has PRI set to 0, and backup mail servers have higher PRI values on their records. When an email message is sent to a domain, each mail server will be contacted starting with the lowest priority until one is found that can successfully receive the mail. When sending email, only one mail server actually receives a copy of the email, and typically, if the mail service is running smoothly, all email for a domain will be received by the same mail server. When sending a batch of email to a domain, once a mail server is found that can receive the batch, no further mail servers will be contacted.
TXT variables can contain arbitrary text. They sometimes contain human-readable information. They often contain data for supporting computer applications. An experimental standard, RFC #1464, specifies a structured format for encoding named attributes in TXT variables. The standard is very simple and is often used to encode machine-readable data in TXT variables in the form of key-value pairs. Named attributes are stored in TXT fields, one per TXT field, with an equal ("=") sign dividing the key and its corresponding value, with a space between the pairs. Since a single TXT field can contain 64 kilobytes of text, it is possible to store a fairly substantial amount of data in one.
DNS is a large topic that can take years to master. It is easier to understand complex DNS manuals if you are familiar with a few critical DNS terms:
While few people completely understand the inner workings of DNS, most of the time, when you look up an Internet domain, it just works! With an understanding of DNS or time and willingness to read manuals and look up details in references, you can Find DNS records to gain insight into name server issues and improve performance.
