Online DNS Record Viewer makes it easy to view all kinds of
Domain Name System
(DNS) records. The DNS is crucial system for today's Internet.
Incorrectly set up
DNS records cause many different problems to administrators of web servers
and company infrastructure. Online DNS Record Viewer can be used to check
various DNS records on arbitrary DNS servers.
Online DNS Record Viewer can become handy even if you are not a server
administrator. As a common user you might want to investigate why are you
unable to reach a certain web site while your friends have no problems with
it. With Online DNS Record Viewer you check the records of your Internet
service provider's (ISP) DNS server and compare it with the information
from the target domain's authoritative DNS server and you find out that
your ISP's server is poorly configured or just holds the old version of the
record in its cache. You can also reveal how systems such as
opendns.com work under the hood.
Fill in the Host / IP address field with the domain name or IP
address you want to query about. Specify a name server of your choice in
the DNS server field, or just leave the "Default" value there
to use one of our DNS servers. Then, in the Query type field,
select the type of DNS record you are interested in and click the "Query!"
button to get your result.
If you want to receive authoritative answer rather than non-authoritative
enable the Require authoritative answer option. Online DNS
Record Viewer will try to contact the authoritative name server for the
specified query and obtain the authoritative answer for you. The specified
name server will be used to find the authoritative name server. If Online
DNS Record Viewer fails to obtain the authoritative answer it will
automatically try to get at least a non-authoritative answer from the
specified name server.
DNS Resource Records
Zone DNS database is a collection of resource records and each of the
records provides information about a specific object. A list of most
common records is provided below:
- Address Mapping records (A)
The record A specifies IP address (IPv4) for given host.
A records are used for conversion of domain names to corresponding
IP addresses.
- IP Version 6 Address records (AAAA)
The record AAAA (also quad-A record) specifies IPv6 address for given
host. So it works the same way as the A record and the difference is
the type of IP address.
- Canonical Name records (CNAME)
The CNAME record specifies a domain name that has to be
queried in order to resolve the original DNS query. Therefore
CNAME records are used for creating aliases of domain names.
CNAME records are truly useful when we want to alias our domain to
an external domain. In other cases we can remove CNAME records and
replace them with A records and even decrease performance overhead.
- Host Information records (HINFO)
HINFO records are used to acquire general information about a host.
The record specifies type of CPU and OS. The HINFO record data provides
the possibility to use operating system specific protocols when two
hosts want to communicate. For security reasons the HINFO records are
not typically used on public servers.
Note: Standard values in RFC 1010
- Integrated Services Digital Network records (ISDN)
The ISDN resource record specifies ISDN address for a host. An ISDN
address is a telephone number that consists of a country code, a
national destination code, a ISDN Subscriber number and, optionally, a
ISDN subaddress. The function of the record is only variation of the A
resource record function.
- Mail exchanger record (MX)
The MX resource record specifies a mail exchange server for a DNS domain name.
The information is used by Simple Mail Transfer Protocol (SMTP) to route emails
to proper hosts. Typically, there are more than one mail exchange server for a
DNS domain and each of them have set priority.
Example:
msn.com MX preference = 5, mail exchanger = mx2.hotmail.com
msn.com MX preference = 5, mail exchanger = mx3.hotmail.com
msn.com MX preference = 5, mail exchanger = mx4.hotmail.com
msn.com MX preference = 5, mail exchanger = mx1.hotmail.com
msn.com nameserver = ns3.msft.net
msn.com nameserver = ns5.msft.net
msn.com nameserver = ns4.msft.net
msn.com nameserver = ns1.msft.net
msn.com nameserver = ns2.msft.net
mx1.hotmail.com internet address = 65.55.92.184
mx1.hotmail.com internet address = 65.54.188.72
mx1.hotmail.com internet address = 65.54.188.94
mx1.hotmail.com internet address = 65.54.188.110
mx1.hotmail.com internet address = 65.54.188.126
mx1.hotmail.com internet address = 65.55.37.72
mx1.hotmail.com internet address = 65.55.37.88
mx1.hotmail.com internet address = 65.55.37.104
mx1.hotmail.com internet address = 65.55.37.120
mx1.hotmail.com internet address = 65.55.92.136
mx1.hotmail.com internet address = 65.55.92.152
mx1.hotmail.com internet address = 65.55.92.168
- Name Server records (NS)
The NS record specifies an authoritative name server for given host.
- Reverse-lookup Pointer records (PTR)
As opposed to forward DNS resolution (A and AAAA DNS records),
the PTR record is used to look up domain names based on an IP address.
- Start of Authority records (SOA)
The record specifies core information about a DNS zone, including
the primary name server, the email of the domain administrator, the
domain serial number, and several timers relating to refreshing the zone.
- Text records (TXT)
The text record can hold arbitrary non-formatted text string.
Typically, the record is used by
Sender Policy Framework
(SPF) to prevent fake emails to appear to be sent by you.
