This post was most recently updated on December 11th, 2018<\/p>
If your site is connected to the Internet, you can use the >nslookup<\/em> (1) program to interactively find MX and other records. To run >nslookup<\/em> , just type its name:<\/p>\n Note that you may have to give the full pathname. Under SunOS, >nslookup<\/em> lives in the \/usr\/etc<\/em> directory; under Ultrix, in \/usr\/ucb<\/em> ; and under HP-UX, in \/usr\/bin<\/em> .<\/p>\n Once >nslookup<\/em> is running, it prints the name of your default name server and the IP address for that machine, then a To tell >nslookup<\/em> to look up only MX records, [14] use the set<\/em> command:<\/p>\n Beginning with V8.7 sendmail<\/em>, you can also use the Now look up some real hosts and domains. First look up the domain sendmail.org<\/em> by entering its name at the prompt:<\/p>\n Note the trailing dot that tells >nslookup<\/em> that the local, default domain should not be appended prior to the lookup. The output produced by the above lookup looks like this:<\/p>\n The first two lines again show the name and IP address of the local DNS server. The next three lines show that the domain Now look up a real UUCP host, www<\/em> . Enter its name as if it were a part of the yahoo.com<\/em> domain:<\/p>\n The output produced shows that www<\/em> has an MX record:<\/p>\n Mail sent to Machines that have MX records do not necessarily have A records. The host www<\/em> is such a machine. You tell >nslookup<\/em> (1) to look up an A record with the set<\/em> command:<\/p>\n The >nslookup<\/em> (1) program is a useful tool for performing all the same lookups that are done by sendmail<\/em> . Each type of lookup corresponds to a set type<\/i> . The list of some available >nslookup<\/em>.<\/p>\n \u00a0<\/p>\n To exit >nslookup<\/em>, just type exit<\/i>.<\/p>\n","protected":false},"excerpt":{"rendered":" This post was most recently updated on December 11th, 2018How to Use nslookup If your site is connected to the Internet, you can use the >nslookup (1) program to interactively find MX and other records. To run >nslookup , just type its name: % >nslookup Note that you may have to give the full pathname. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-159","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/www.bleuanus.nl\/index.php\/wp-json\/wp\/v2\/posts\/159","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bleuanus.nl\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bleuanus.nl\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bleuanus.nl\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bleuanus.nl\/index.php\/wp-json\/wp\/v2\/comments?post=159"}],"version-history":[{"count":1,"href":"https:\/\/www.bleuanus.nl\/index.php\/wp-json\/wp\/v2\/posts\/159\/revisions"}],"predecessor-version":[{"id":252,"href":"https:\/\/www.bleuanus.nl\/index.php\/wp-json\/wp\/v2\/posts\/159\/revisions\/252"}],"wp:attachment":[{"href":"https:\/\/www.bleuanus.nl\/index.php\/wp-json\/wp\/v2\/media?parent=159"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bleuanus.nl\/index.php\/wp-json\/wp\/v2\/categories?post=159"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bleuanus.nl\/index.php\/wp-json\/wp\/v2\/tags?post=159"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}\n
%
>nslookup<\/b> <\/code><\/pre>\n<\/blockquote>\n><\/code> character as a prompt and awaits input:<\/p>\n\n
Server: Your.Main.ServerAddress: 123.45.67.8><\/pre>\n<\/blockquote>\n
\/mx<\/code> command in -bt<\/code> rule-testing mode to look up MX records.<\/p>\n\n
>
set type=mx<\/b> <\/code>><\/pre>\n<\/blockquote>\n\n
>
sendmail.org.<\/b> <\/code><\/pre>\n<\/blockquote>\n\n
>
sendmail.org.<\/b> <\/code>Server:Address: 123.45.67.8sendmail.org preference = 20, mail exchanger = mail1.reference.comsendmail.org preference = 30, mail exchanger = mail2.reference.comsendmail.org preference = 10, mail exchanger = mail.mailsite.rutgers.edumail1.reference.com inet address = 206.171.3.24mail2.reference.com inet address = 128.102.240.18mail.mailsite.rutgers.edu inet address = 204.247.98.2><\/pre>\n<\/blockquote>\nsendmail.org<\/code> has three MX records. Mail addressed to that domain is sent to the machine with the lowest preference (cost), which happens to be mail.mailsite.rutgers.edu<\/code> . If that machine is down (or not accepting mail), the message is sent to the machine with the next higher cost, mail1.reference.com<\/code> . The last three lines show the IP addresses (A records) for those machines.<\/p>\n\n
>
www.yahoo.com.<\/b> <\/code><\/pre>\n<\/blockquote>\n\n
www.yahoo.com preference = 5, mail exchanger = .yahoo.com.yahoo.com inet address = 128.32.201.15><\/pre>\n<\/blockquote>\n
www.yahoo.com<\/code> is instead delivered to the machine named .yahoo.com<\/code> , which in turn forwards that mail over a dial-up line to the UUCP host www<\/em> .<\/p>\n\n
>
set type=a<\/b> <\/code>> www.yahoo.com.<\/b> <\/code>*** No address information available for www.yahoo.com.<\/pre>\n<\/blockquote>\n\n
\n \nType<\/th>\n Description<\/th>\n<\/tr>\n<\/thead>\n \n a<\/td>\n IP address<\/td>\n<\/tr>\n \n cname<\/td>\n Canonical name for an alias<\/td>\n<\/tr>\n \n hinfo<\/td>\n Host CPU and operating system type<\/td>\n<\/tr>\n \n mx<\/td>\n Mail exchanger records<\/td>\n<\/tr>\n \n ns<\/td>\n Name server record<\/td>\n<\/tr>\n \n any<\/td>\n Union of all records<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n