The dig command stands for Domain Information Groper. It is a network administration command-line tool for querying the Domain Name System (DNS). The dig
command is useful for network troubleshooting and for educational purposes. It can operate based on command line option and flag arguments, or in batch mode by reading requests from an operating system file. When a specific name server is not specified in the command invocation, it uses the operating system's default resolver, usually configured in the file resolv.conf. Without any arguments it queries the DNS root zone. Syntax: dig is very easy
to use, and works well without any options. The list of options is quite long, feel free to consult the man page for this command. The following example is a simple lookup of the IP address for the server specified on the command line - deltacollege.edu. The lines that begin with a semi-colon provide comments about the output. pbmac@pbmac-server $ dig deltacollege.edu
; <<>> DiG 9.11.3-1ubuntu1.11-Ubuntu <<>> deltacollege.edu
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 64205
;; flags: qr rd ra; QUERY: 1, Answer: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;deltacollege.edu. IN A
;; Answer SECTION:
deltacollege.edu. 3599 IN A 52.36.131.229
The nslookup Commandnslookup is a network administration command-line tool available in many computer operating systems for querying the Domain Name System (DNS) to obtain domain name or IP address mapping, or other DNS records. The name "nslookup" means "name server lookup." The command does not use the operating system's local Domain Name System resolver library to perform its queries, and thus may behave differently from dig, which it does. Additionally, vendor-provided versions may include output of other sources of name information, such as host files and Network Information Service. Some behaviors of nslookup may be modified by the contents of resolv.conf. Syntax: nslookup [ OPTION ] [name | -] [server] It is possible to use nslookup in a command line mode, or an interactive mode. In the first example the command prints output and returns to the system prompt. In the second example issuing nslookup alone takes the user to a command prompt where command specific input can be entered. pbmac@pbmac-server $ nslookup deltacollege.edu Server: 8.8.8.8 Address: 8.8.8.8#53 Non-authoritative answer: Name: deltacollege.edu Address: 52.36.131.229 pbmac@pbmac-server $ nslookup > deltacollege.edu Server: 8.8.8.8 Address: 8.8.8.8#53 Non-authoritative answer: Name: deltacollege.edu Address: 52.36.131.229 > The host CommandThe host command in Linux system is used for DNS (Domain Name System) lookup. It is used to find the IP address of a particular domain name, or if you want to find out the domain name of a particular IP address the host command becomes handy. You can also find more specific details of a domain by specifying the corresponding option along with the domain name. Syntax: host [ OPTIONS ] hostname Command Options
Without a hostname the command will print out the command options. Using the -v option generates a very verbose output - gives a lot of information. pbmac@pbmac-server $ host -v deltacollege.edu
Trying "deltacollege.edu"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 53400
;; flags: qr rd ra; QUERY: 1, Answer: 1, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;deltacollege.edu. IN A
;; Answer SECTION:
deltacollege.edu. 3599 IN A 52.36.131.229
Received 50 bytes from 8.8.8.8#53 in 164 ms
Trying "deltacollege.edu"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4462
;; flags: qr rd ra; QUERY: 1, Answer: 0, AUTHORITY: 1, ADDITIONAL: 0
;; QUESTION SECTION:
;deltacollege.edu. IN AAAA
;; AUTHORITY SECTION:
deltacollege.edu. 1799 IN SOA sdc-ns2.deltacampus.net. hostmaster.deltacollege.edu. 2015121323 1200 600 1209600 3600
Received 104 bytes from 8.8.8.8#53 in 187 ms
Trying "deltacollege.edu"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 41683
;; flags: qr rd ra; QUERY: 1, Answer: 4, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;deltacollege.edu. IN MX
;; Answer SECTION:
deltacollege.edu. 3599 IN MX 20 mailin.deltacollege.edu.
deltacollege.edu. 299 IN MX 15 mailin1.deltacollege.edu.
deltacollege.edu. 3599 IN MX 5 deltacollege-edu.mail.protection.outlook.com.
deltacollege.edu. 3599 IN MX 15 mailin3.deltacollege.edu.
Received 165 bytes from 8.8.8.8#53 in 133 ms
Adapted from: Which of the following is a Linux command line command used for configuring network interface parameters specific to the wireless communication?Linux iwconfig is used to configure the wireless network interface.
Which of the following CLI tools can be used for troubleshooting DNS related problems?Which of the following CLI tools is used to troubleshoot DNS-related problems? Domain information groper (dig) and nslookup are command-line tools used for DNS queries.
What is the name of a Windows command line utility that can be used to display TCP Ipconfiguration settings?The ipconfig (short for IP Configuration) is a basic, yet popular, Windows network command-line utility used to display the TCP/IP network configuration of a computer. If you are familiar with Linux, this tool is similiar to ifconfig. This tool is often used for troubleshooting network connectivity issues.
Which of the following Windows command line utilities can be used to renew an IP address?The ipconfig command
On a Windows computer, use the following information to release and renew your IP address: Go to "Start > Run" and type " cmd " (no quotes), then select "OK" Type " ipconfig /release " (no quotes) and press "Enter" Once the prompt returns, type " ipconfig /renew " (no quotes), then hit "Enter,"
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