NEA-SEA ITC 2009 NSLOOKUP  March 2009 ITC Jay Hall
Quick DNS Record Type Review <ul><li>A </li></ul><ul><ul><li>Maps a host name to an IPv4 address. </li></ul></ul><ul><li>C...
Quick DNS Record Type Review <ul><li>NS </li></ul><ul><ul><li>Authoritative Name Server for the zone. </li></ul></ul><ul><...
What is nslookup? <ul><li>Used in Windows and *NIX systems to query DNS servers to find </li></ul><ul><ul><li>details of t...
Using nslookup <ul><li>nslookup has two modes </li></ul><ul><ul><li>command line and  </li></ul></ul><ul><ul><li>interacti...
nslookup commands <ul><li>server aa.dd.re.ss </li></ul><ul><ul><li>IP address, or name, of the server to use for DNS queri...
nslookup commands <ul><li>server  name </li></ul><ul><ul><li>Use the specified server for queries.  Can be an IP address o...
nslookup examples jhall@jefmhallja-~$ nslookup > set type=mx > server 10.129.10.41 Default server: 10.129.10.41Address: 10...
nslookup examples <ul><li>jhall@jefmhallja-~$ nslookup -type=mx mnea.org mo-hq-s1.mo.loc </li></ul><ul><li>Server: mo-hq-s...
nslookup examples <ul><li>> set type=a </li></ul><ul><li>> mail.mnea.org </li></ul><ul><li>Server: ns3.socket.net </li></u...
nslookup examples <ul><li>> server mo-hq-s1.mo.loc </li></ul><ul><li>Default server: mo-hq-s1.mo.loc </li></ul><ul><li>Add...
What is Dig? <ul><li>Domain Information Groper </li></ul><ul><li>Has the same uses as nslookup. </li></ul><ul><li>ISC is s...
Dig Commands and Examples <ul><li>dig @server name type </li></ul><ul><ul><li>Type can be any valid DNS record type. </li>...
Dig Commands and Examples ;;  QUESTION SECTION: ;mnea.org. IN A ;; ANSWER SECTION: mnea.org. 900 IN A 65.117.48.158 ;; AUT...
Dig Commands and Examples ;; QUESTION SECTION: ;mnea.org. IN MX ;; ANSWER SECTION: mnea.org. 900 IN MX 5 mail.mnea.org. ;;...
Why are DNS tools useful? <ul><li>Comparing results between servers. </li></ul><ul><ul><li>Internal v. external </li></ul>...
A better way? <ul><li>There has to be a better way to this. </li></ul><ul><li>There is. </li></ul><ul><li>http://www.dnsst...
DNSStuff.com Demonstration
<ul><ul><li>The End </li></ul></ul>
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2009 Itc Nslookup Rev01

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Revised nslookup and dig presentation for the 2009 ITC.

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2009 Itc Nslookup Rev01

  1. 1. NEA-SEA ITC 2009 NSLOOKUP March 2009 ITC Jay Hall
  2. 2. Quick DNS Record Type Review <ul><li>A </li></ul><ul><ul><li>Maps a host name to an IPv4 address. </li></ul></ul><ul><li>CNAME </li></ul><ul><ul><li>Alias of one name to another (canonical name). </li></ul></ul><ul><li>MX </li></ul><ul><ul><li>Mail eXchanger record. </li></ul></ul>
  3. 3. Quick DNS Record Type Review <ul><li>NS </li></ul><ul><ul><li>Authoritative Name Server for the zone. </li></ul></ul><ul><li>PTR </li></ul><ul><ul><li>PoinTer Record. Only returns a name. Commonly used for reverse DNS. </li></ul></ul>
  4. 4. What is nslookup? <ul><li>Used in Windows and *NIX systems to query DNS servers to find </li></ul><ul><ul><li>details of the zone </li></ul></ul><ul><ul><ul><li>including IP addresses. </li></ul></ul></ul><ul><ul><ul><li>A, MX and other records for the zone </li></ul></ul></ul><ul><ul><ul><li>primary name server addresses for the zone. </li></ul></ul></ul>
  5. 5. Using nslookup <ul><li>nslookup has two modes </li></ul><ul><ul><li>command line and </li></ul></ul><ul><ul><li>interactive. </li></ul></ul><ul><li>Personally, I think interactive mode is easier to use. </li></ul><ul><ul><li>Mainly because I cannot remember the command line parameters. </li></ul></ul>
  6. 6. nslookup commands <ul><li>server aa.dd.re.ss </li></ul><ul><ul><li>IP address, or name, of the server to use for DNS queries. </li></ul></ul><ul><li>set </li></ul><ul><ul><li>domain=name </li></ul></ul><ul><ul><ul><li>set a default domain name. </li></ul></ul></ul><ul><ul><li>type </li></ul></ul><ul><ul><ul><li>type of record to search for. </li></ul></ul></ul><ul><ul><ul><li>A, ANY, CNAME, MX, NS, PTR, SOA. </li></ul></ul></ul>
  7. 7. nslookup commands <ul><li>server name </li></ul><ul><ul><li>Use the specified server for queries. Can be an IP address or a name. </li></ul></ul><ul><li>ls (Windows only)‏ </li></ul><ul><ul><li>List the addresses in the domain. </li></ul></ul><ul><ul><li>-t specifies the type to list. </li></ul></ul>
  8. 8. nslookup examples jhall@jefmhallja-~$ nslookup > set type=mx > server 10.129.10.41 Default server: 10.129.10.41Address: 10.129.10.41#53 > server mo-hq-s1.mo.loc Default server: mo-hq-s1.mo.loc Address: 10.129.10.41#53 > mnea.org Server: mo-hq-s1.mo.loc Address: 10.129.10.41#53 mnea.org mail exchanger = 20 mail2.mnea.org. mnea.org mail exchanger = 10 mo-hq-s1.mo.loc. >
  9. 9. nslookup examples <ul><li>jhall@jefmhallja-~$ nslookup -type=mx mnea.org mo-hq-s1.mo.loc </li></ul><ul><li>Server: mo-hq-s1.mo.loc </li></ul><ul><li>Address: 10.129.10.41#53 </li></ul><ul><li>mnea.org mail exchanger = 10 mo-hq-s1.mo.loc. </li></ul><ul><li>mnea.org mail exchanger = 20 mail2.mnea.org. </li></ul>
  10. 10. nslookup examples <ul><li>> set type=a </li></ul><ul><li>> mail.mnea.org </li></ul><ul><li>Server: ns3.socket.net </li></ul><ul><li>Address: 70.246.240.169#53 </li></ul><ul><li>Non-authoritative answer: </li></ul><ul><li>Name: mail.mnea.org </li></ul><ul><li>Address: 65.117.48.157 </li></ul>
  11. 11. nslookup examples <ul><li>> server mo-hq-s1.mo.loc </li></ul><ul><li>Default server: mo-hq-s1.mo.loc </li></ul><ul><li>Address: 10.129.10.41#53 </li></ul><ul><li>> mail.mnea.org </li></ul><ul><li>Server: mo-hq-s1.mo.loc </li></ul><ul><li>Address: 10.129.10.41#53 </li></ul><ul><li>Name: mail.mnea.org </li></ul><ul><li>Address: 10.129.10.45 </li></ul>
  12. 12. What is Dig? <ul><li>Domain Information Groper </li></ul><ul><li>Has the same uses as nslookup. </li></ul><ul><li>ISC is slowly replacing nslookup with dig due to security concerns. </li></ul><ul><li>In my opinion, dig is easier to use. </li></ul>
  13. 13. Dig Commands and Examples <ul><li>dig @server name type </li></ul><ul><ul><li>Type can be any valid DNS record type. </li></ul></ul><ul><li>Dig has a special query type called axfr. </li></ul><ul><ul><li>This initiates a zone transfer so all of the zone data can be seen. </li></ul></ul><ul><ul><li>Some servers do not allow this. </li></ul></ul>
  14. 14. Dig Commands and Examples ;; QUESTION SECTION: ;mnea.org. IN A ;; ANSWER SECTION: mnea.org. 900 IN A 65.117.48.158 ;; AUTHORITY SECTION: mnea.org. 900 IN NS dca-ans-01.inet.qwest.net. mnea.org. 900 IN NS svl-ans-01.inet.qwest.net. ;; ADDITIONAL SECTION: dca-ans-01.inet.qwest.net. 3600 IN A 205.171.9.242 svl-ans-01.inet.qwest.net. 3600 IN A 205.171.14.195 ;; Query time: 107 msec ;; SERVER: 205.171.9.242#53(205.171.9.242)‏ ;; WHEN: Wed Feb 25 05:34:06 2009 ;; MSG SIZE rcvd: 138
  15. 15. Dig Commands and Examples ;; QUESTION SECTION: ;mnea.org. IN MX ;; ANSWER SECTION: mnea.org. 900 IN MX 5 mail.mnea.org. ;; AUTHORITY SECTION: mnea.org. 900 IN NS dca-ans-01.inet.qwest.net. mnea.org. 900 IN NS svl-ans-01.inet.qwest.net. ;; ADDITIONAL SECTION: mail.mnea.org. 900 IN A 65.117.48.157 dca-ans-01.inet.qwest.net. 3600 IN A 205.171.9.242 svl-ans-01.inet.qwest.net. 3600 IN A 205.171.14.195 ;; Query time: 97 msec ;; SERVER: 205.171.9.242#53(205.171.9.242)‏ ;; WHEN: Wed Feb 25 05:49:26 2009 ;; MSG SIZE rcvd: 159
  16. 16. Why are DNS tools useful? <ul><li>Comparing results between servers. </li></ul><ul><ul><li>Internal v. external </li></ul></ul><ul><ul><li>Ensuring zone data has propagated from primary to secondary name servers. </li></ul></ul><ul><ul><li>Troubleshooting web access problems. </li></ul></ul>
  17. 17. A better way? <ul><li>There has to be a better way to this. </li></ul><ul><li>There is. </li></ul><ul><li>http://www.dnsstuff.com </li></ul><ul><li>Thank you to DNSStuff for their donation of two one year memberships. </li></ul>
  18. 18. DNSStuff.com Demonstration
  19. 19. <ul><ul><li>The End </li></ul></ul>

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