Network + 5.10

You are troubleshooting a network connectivity issue on a Unix system. You are able to connect to remote systems by using their IP address, but unable to connect using the hostname. You check the TCP/IP configuration, and note that a DNS server IP address is configured. You decide to run some manual resolution queries to ensure that the communication between the Unix system and the DNS server are working correctly. Which utilities can you use to do this?

-dig -nslookup

You need to perform a reverse lookup of the 10.0.0.1 IP address. Which command can you use to accomplish this?

-dig -x 10.0.0.3 -nslookup 10.0.0.3

· What are the symptoms of name resolution problems?

1. You csn ping s destination host using its IP address but not its host name. 2. Applications that use host names fail. this could include:- Entering a URL into a browser.- Pinging the host using the host name.- Searching for the host by its name.

· What is the difference between nslookup and dig?

1. nslookup: starts nslookup in interactive mode. The default interactive mode query is for A records, but you can use the(set type=) command to change the quarry type. nslookup setExample: type=ns 2. dig: quaries a host. The default query is for A records. You can change the default search by appending one of the record types below to the end of the command:- a- address- any- any type of records- mx- mail exchange records- ns- name server records- soa- sort of authority records- info- host info records- axfr- all records in the zone- txt- text recordsdig-Examples: www.vulture.com

Consider the following output from a dig command run on a Linux system. ; <<>> DiG 8 .2 <<>> westsimlll.com ;;res options :init recurs defnam dnsrch ;;got answer : ;;->>HEADER<< -opcode :QUERY , status : NOERROR , id :4 ;;flags : qr rd ra ; QUERY :l , ANSWER :l , AUTHORITY :2, ADDITIONAL :0 ;;QUERY SECTION : ;; westsimlll.com , type= A , class= IN ;;ANSWER SECTION : westsimlll .com . 7h33m IN A 76 .141 .43 .129 ;;AUTHORITY SECTION : westsimlll .com . 7h33m INNS dnsl .deriatctlll .com. westsimlll.com. 7h33m INNS dns2.de riatct222.com . ;;Total query time : 78 msec ;;FROM: localhost .localdomain to SERVER :default -- 202 .64 .49 .150 ;;WHEN: Tue Feb 16 23 :21 :24 2005 ;;MSG SIZE sent : 30 rcvd :l03 What is the IP address of the DNS server that performed this name resolution?

202.64.49.150

nslookup

A utility that is used to test and troubleshoot domain name servers.

Consider the following output from a dig command run on a Linux system. ; <<>> DiG 8 .2 <<>> westsimlll.com ;;res options :init recurs defnam dnsrch ;;got answer : ;;->>HEADER<< -opcode :QUERY , status : NOERROR , id :4 ;;flags : qr rd ra ; QUERY :l , ANSWER :l , AUTHORITY :2, ADDITIONAL :0 ;;QUERY SECTION : ;; westsimlll.com , type= A , class= IN ;;ANSWER SECTION : westsimlll .com . 7h33m IN A 76 .141 .43 .129 ;;AUTHORITY SECTION : westsimlll .com . 7h33m INNS dnsl .deriatctlll .com. westsimlll.com. 7h33m INNS dns2.de riatct222.com . ;;Total query time : 78 msec ;;FROM: localhost .localdomain to SERVER :default -- 202 .64 .49 .150 ;;WHEN: Tue Feb 16 23 :21 :24 2005 ;;MSG SIZE sent : 30 rcvd :l03 which of the following utilities produced this output?

Dig

tracert or traceroute

commands used to show details about the path that a packet takes from the computer to whatever destination you specify.

A user reports that he can't browse to a specific Web site on the Internet. From his computer, you find that a ping test to the Web server succeeds. A trace route test shows that 17 hops to the destination Web server. What is the most likely cause of the problem?

incorrect DNS server address

Domain Information Groper (DIG)

is a Unix-like network administration command-line tool used to determine what a particular DNS server thinks the given host's IP address should be.

Examine the following output : Server : helicuplar.xct.takro.net Address : 209.53.4.130 Name : westsim.com Address : 64.78.193.84 Which of the following utilities produced this output?

nslookup

Mary calls to tell you that she can't connect to an intranet server called WebSrvl. From her computer, you ping the server's IP address. The ping test is successful. Which tool would you use on her workstation next to troubleshoot the problem?

nslookup