The busybox nslookup, which alpine uses, does two lookups, one for the dns server and one for the name you asked for. Your primary dns server will return authorative answers when queried about your hosts, but to get authorative answers for you would need to ask their dns server. However, the answer in this section is nonauthoritative because it originates from a server cachens1. This is a test environment with a fresh installation of pfsense 2. Nslookup resolves name but not address dns spiceworks. When a dns query is given, it searches the cache file, and return the information available as nonauthoritative answer. I believe that you receive a nonauthoritative answer because, by default, nslookup asks your nameserver to recurse in order to resolve your query and because your nameserver is not an authority for the name you are asking it about. Although i dont know the solution yet, i bet if you go to any other computer linux, windows, unix that use the same dns server and try to resolve any host name and end it with a dot. Again you can see that we are asking the zen dns servers and the result or nonauthoritative answer is an address of 82. The main use of nslookup is for troubleshooting dns related problems nslookup can be use in interactive and noninteractive. I believe that you receive a non authoritative answer because, by default, nslookup asks your nameserver to recurse in order to resolve your query and because your nameserver is not an authority for the name you are asking it about. What the nslookup tool can tell you about internet domains.
Actually the non authoritative answer means that the dns server queried by nslookup is not authoritative for the domain. Its because when you use nslooku, the answer is not coming directly from the name server of the server you are querying. Noninteractive mode is used when the name or internet address of the host to be looked up. Nslookup is a program to query internet domain name servers. In the output of nslookup command, youll often notice nonauthoritative answer. This behavior depends on the state of the following set subcommands. The same for dns3 and dns4 dig and nslookup run on those servers all work fine. It works with the name server that your system is configured to use as defined in the etcnf file. The output shows that the non authoritative answer is the same hotname i used to try the query on the name line but then the next line should be ip address it blanks and it just returns to the command prompt. It is a network administration tool for querying the domain name system dns to obtain domain name or ip address mapping or any other specific dns record.
You can get an authoritative answer by querying the authoritative nameserver for the domain you are interested in. Get an authoritative answer to get an authoritative answer you need to specify the authoritative primary name server at the end of the request. Linux nslookup command help and examples computer hope. It is used for querying the domain name system dns to obtain domain name or ip address mapping information. In simple words, if you have a name eg and you want to know the ip of it, you can use this command. For example, to change the default query type to host computer information and the initial timeout to 10 seconds, type. What is authoritative and nonauthoritative dns server tecadmin. Then when i type nslookup and my domain name i get my domain name, and something about a non authoritative answer. In this article, you will learn how to install the dig command and nslookup command on linux.
When i nslookup behind our firewall i got non authoritative answer like this non authoritative answer. They have a cache file for the domains that is constructed from all the dns lookups done previously. To get the answer for the question why we get non authoritative answer on ns lookup like this. Heres how to get that information assuming youve already typed nslookup into command prompt. Noninteractive mode is used to print just the name and requested information for a host or domain. Then when i type nslookup and my domain name i get my domain name, and something about a. If computertofind is an ip address and the query is for an a or ptr resource record type, the name of the computer is returned. If a dns server responded for a dns query which doesnt have original file is known as a nonauthoritative answer. This can be seen here in your example nslookup did resolve the name hostdev1vm01core to the address 10. How to choose a vps or virtual private server by a starter or someone who wants to shift from free blogs like. Has anyone seen when an nslookup query resolves a hostname but not ip. The only firewall rules other than the defaults allow all traffic from lan to wan and dns from lan to pfsense and from pfsense to its forwarders 1.
This servers have authority from and all other nameservers are nonauthoritative nameservers. Dec 03, 2010 noninteractive mode is used to print just the name and requested information for a host or domain. An authoritative answer comes from a nameserver that is considered authoritative for the domain which its returning a record for one of the nameservers in the list for the domain you did a lookup on, and a nonauthoritative answer comes from anywhere else a nameserver not in the list for the domain you did a lookup on. But in order to have a tool mentioned above, dig and nslookup, there is a step which is needed to be taken so that it can be available to be executed from the linux operating system associated. Aug, 2012 nslookup is a commandline administrative tool for testing and troubleshooting dns servers domain name server. These commands are used for network troubleshooting and gathering information about domain names dig, short for domain information gopher, is a dns lookup utility used for probing dns servers and troubleshooting problems associated with dns. It is used to query specific dns resource records rr as well. Articles related to why we get nonauthoritative answer on ns lookup. In this case, the response is a nonauthoritative answer. Nslookup or name server lookup is a tool used by network administrators to find the.
Jun 28, 2019 it is command to query internet name servers. Jul 25, 2019 nonauthoritative name servers do not contain original source files of domains zone. Interactive mode allows the user to query name servers for information about various hosts and domains or to print a list of. This may be wrong as its too early to grab my notes, but im certain authoritative is when you nslookup a domain which isnt already cached, and non authoritative occurs when the address you are looking for has already been cached, allowing us to retrieve the information faster. Reverse nslookup command nixcraft nixcraft linux tips. A nonauthoritative answer simply means that the name server you are communicating with has received this information from another name server. I am trying to use the code nslookup qmx to find the mail server of, but its not working on my ubuntu. Hi all, if i give the hostname followed by nslookup, i get the output like below, commandprompt nslookup efgh using etchosts on. Oct 16, 2017 each commandline option consists of a hyphen followed immediately by the command name and, in some cases, an equal sign and then a value. The interactive mode is used to query dnsserver about various domains and hosts. Nslookup is used for handling dns lookups and displays crucial information such as mx records, and the ip address associated with a domain name. X after appending period to the fqdn it is correct, it no longer returns a public ip address for our web server and appends our domain to the external fqdn.
Jan 23, 2019 the busybox nslookup, which alpine uses, does two lookups, one for the dns server and one for the name you asked for. An authoritative answer comes from a nameserver that is considered authoritative for the domain which its returning a record for one of the nameservers in the list for the domain you did a lookup on, and a non authoritative answer comes from anywhere else a nameserver not in the list for the domain you did a lookup on. Linux nslookup command help, examples, and information. Specific tool which is important in an operating system where in this context, it is linux operating system, it is dig and nslookup. How to check mx record using nslookup command on windows nslookup is a commandline tool for network administrator and system administrator that available in many computer operating systems such as linux and windows for querying the domain name system dns. Please note that the host, dig and nslookup are also part of the bind utilities.
Nonauthoritative answer indicates we have got the cached reply from the. This subchapter looks at nslookup, a unix and linux command nslookup is used to obtain domain name and ip information about a server information. The output shows that the nonauthoritative answer is the same hotname i used to try the query on the name line but then the next line should be ip address it blanks and it just returns to the command prompt. Noninteractive mode is used to query about information of a domain or host you might also be interested in following article. If computertofind is a name and does not have a trailing period, the default dns domain name is appended to the name. How to use dig and nslookup in centos 7 just another. Hi all, if i give the hostname followed by nslookup, i get the output like below, commandpromptnslookup efgh using etchosts on. In this linux tip, were going to look at the nslookup command. Linux nslookup command help and examples for dns lookup. It means that the answer you got for your dns query is coming for a nonauthoritative source. But avoid asking for help, clarification, or responding to other answers. To get the answer for the question why we get nonauthoritative answer on ns lookup like this. In dns, socalled nonauthoritative answers refer to dns records kept on external dns servers, which they obtained from the authoritative servers that provide the original source of the data. Yet, im getting a nonauthoritative answer, implying the a record is cached on my dns server.
So now the sending mail server knows to open an smtp connection to the ip address of our mdaemon server on 82. Sep 11, 2017 specific tool which is important in an operating system where in this context, it is linux operating system, it is dig and nslookup. If host is an internet address and the query type is a or ptr, the name of the host is returned. Need info about a nslookup nonauthoritative response. Aug 18, 2014 in this case, the response is a nonauthoritative answer. Reverse nslookup command nixcraft linux tips, hacks. Why cant i get an authoritative answer from a dns server.
Nov 20, 2015 has anyone seen when an nslookup query resolves a hostname but not ip. Cant find my192 no answer what works ive found that if i change the a record for my192. How to check mx record using nslookup command on windows. To specify a specific dns server to use for a query, you need to provide the dns server address as the second parameter. In this article, all the commands explained are noninteractive mode. The only firewall rules other than the defaults allow all traffic from lan to wan and dns from lan to pfsense and f. In this case, the response is a non authoritative answer. Dns nslookup what is the meaning of the nonauthoritative. Now if we change the dns server to one of the ns in the list and then do a nslookup against subdomain. Nonauthoritative name servers do not contain original source files of domains zone. In this case, a nonauthoritative answer notification is given, as the local. Interactive mode allows the user to query name servers for information about various hosts and domains or to print a list of hosts in a domain.
It can be used in most of the os platforms including the most popular linux,windows etc. If an authoritative answer cant be found, the names of servers that might have the. Why cant i get an authoritative answer from a domain name. Reverse nslookup returns lame nonauthoritative answer. This article demonstrates widely used nslookup command in detail. Reading your request, you seem to try to display mx ip adress for a domain but, nslookup first lines report only name and ip address of your configured dns. We can also perform reverse nslookup to resolve hostname against an ip address. Nslookup stands for name server lookup is a useful command for getting information from dns server. Experts, i have a need to lookup ip addresses to find their dns. What is authoritative and nonauthoritative dns server. When i nslookup behind our firewall i got nonauthoritative answer like this nonauthoritative answer. How to install and use dig and nslookup commands in linux.
Nonauthoritative answer is expected output when the dns server that returned the result to you is not directly the authoritative nameserver. May 23, 2019 a nonauthoritative answer simply means that the name server you are communicating with has received this information from another name server. When i type nslookup and my ip number i get the namei think that my isp gives me on his machine. Nov 12, 2019 in dns, socalled non authoritative answers refer to dns records kept on external dns servers, which they obtained from the authoritative servers that provide the original source of the data. Yet, im getting a non authoritative answer, implying the a record is cached on my dns server. Newer linux system ship both dig and nslookup utilities by default. Non interactive mode is used to print just the name and requested information for a host or domain. I have obviously misconfigured something in dns2, 3, and 4 but i dont know what.
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