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CompTIA Network+ Certification Study Guide part 58

CompTIA’s Network+ certification Study Guide part 58 is a globally-recognized, vendor neutral exam that has helped over 235,000 IT professionals reach further and higher in their careers. The 2009 Network+ exam (N10-004) is a major update with more focus on security and wireless aspects of networking. Our new study guide has been updated accordingly with focus on network, systems, and WAN security and complete coverage of today’s wireless networking standards. | 556 CHAPTER 11 Network Troubleshooting Tools Unlike nslookup there is no interactive mode for nslookup- you ll specify all of the necessary command line switches each time you issue the command. Each of these switches specifies certain behavior for the dig command as follows @server This is the name of the computer you re querying for. Unlike nslookup dig requires you to use the Fully Qualified Domain Name FQDN of the host you re looking for. Therefore dig server1.mycompany.com is correctly formatted while dig serverl would return an error. -b address If you have multiple NICs installed on your computer this switch will specify the IP address that you want the query to be sent from. This is useful if you have NICs attached to different networks and you are trying to isolate which network is experiencing the name resolution failure. -t type This specifies the type of record you re looking for like an MX or SRV record. -f filemane This will allow dig to operate in batch mode where it will perform multiple queries that it reads in from a text file. -p port This will issue a DNS query on a non-standard port. Exam Warning Remember that the default DNS port is 53. DNS queries use UDP port 53 and DNS zone transfers use TCP port 53. no tcp Specifies whether to use TCP or UDP when performing a DNS query. dig www.mycompany.com tcp will perform the query using TCP. dig www.mycompny.com no tcp will issue the query using UDP. domain domainname Searches for a host using only the domain name that you specify rather than using the search list that the Linux computer is configured with. no recursive Specifies whether to use an iterative or a recursive query. Dig queries are recursive by default so issuing the dig www.mycompany. com no recursive would instruct dig to use an iterative query. time Time Specifies the time in seconds that dig should wait before deciding that a query has timed out. The default value is five seconds. NetWare Tools 557 Utilizing the traceroute Command As .