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Linux System Administration
book

Linux System Administration

by Tom Adelstein, Bill Lubanovic
March 2007
Intermediate to advanced content levelIntermediate to advanced
304 pages
11h 12m
English
O'Reilly Media, Inc.
Content preview from Linux System Administration
Editing the Configuration Files
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61
# dig centralsoft.org
; <<>> DiG 9.2.1 <<>> centralsoft.org
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 48489
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;centralsoft.org. IN A
;; ANSWER SECTION:
centralsoft.org. 86400 IN A 70.253.158.42
;; Query time: 198 msec
;; SERVER: 81.169.163.104#53(81.169.163.104)
;; WHEN: Sat Mar 11 18:55:21 2006
;; MSG SIZE rcvd: 49
As you see, this lookup returns the IP address 70.253.158.42.
Now we can do a reverse lookup:
# dig -x 70.253.158.42
; <<>> DiG 9.2.1 <<>> -x 70.253.158.42
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4096
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;42.158.253.70.in-addr.arpa. IN PTR
;; ANSWER SECTION:
42.158.253.70.in-addr.arpa. 5304 IN PTR centralsoft.org.
;; Query time: 2 msec
;; SERVER: 81.169.163.104#53(81.169.163.104)
;; WHEN: Sat Mar 11 18:57:54 2006
;; MSG SIZE rcvd: 98
The forward and reverse lookups match each other. Our primary server setup is
complete.
Configuring the Secondary Nameserver
Next, let’s set up our secondary nameserver, server2.centralsoft.org. It will act as a
backup nameserver in case the primary (server1.centralsoft.org) fails, so that people
can still look up centralsoft.org and its subdomains.
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Publisher Resources

ISBN: 9780596009526Supplemental ContentCatalog PageErrata