200.212.69.195.in-addr.arpa name = www.environment.pearson.com.
200.212.69.195.in-addr.arpa name = booktime.pearson.com.
Authoritative answers can be found from:
212.69.195.in-addr.arpa nameserver = ns2.pearson.com.
212.69.195.in-addr.arpa nameserver = ns.pearson.com.
ns2.pearson.com internet address = 195.69.215.15
Note that using a reverse lookup does not tell you the FQDN of the server using that IP address. To determine that, you have to use the whois client.
whois
A command-line utility from the whois package, whois queries various whois servers across the Internet.
For an IP lookup:
$ whois 165.193.130.83
[Querying whois.arin.net]
[whois.arin.net]
OrgName: Savvis
OrgID: SAVVI-3
Address: 3300 Regency Parkway
City: Cary
StateProv: NC
PostalCode: 27511
Country: US
NetRange: 165.193.0.0 - 165.193.255.255
CIDR: 165.193.0.0/16
NetName: SAVVIS
NetHandle: NET-165-193-0-0-1
Parent: NET-165-0-0-0-0
NetType: Direct Allocation
NameServer: NS01.SAVVIS.NET
NameServer: NS02.SAVVIS.NET
NameServer: NS03.SAVVIS.NET
NameServer: NS04.SAVVIS.NET
NameServer: NS05.SAVVIS.NET
Comment:
RegDate:
Updated: 2007-09-18
OrgAbuseHandle: ABUSE11-ARIN
OrgAbuseName: Abuse
OrgAbusePhone: +1-877-393-7878
OrgAbuseEmail: [email protected]
OrgNOCHandle: NOC99-ARIN
OrgNOCName: SAVVIS Support Center
OrgNOCPhone: +1-888-638-6771
OrgNOCEmail: [email protected]
OrgTechHandle: UIAA-ARIN
OrgTechName: US IP Address Administration
OrgTechPhone: +1-888-638-6771
OrgTechEmail: [email protected]
# ARIN WHOIS database, last updated 2007-10-27 19:10
# Enter ? for additional hints on searching ARIN's WHOIS database.
And for a domain name lookup (which is not what whois is used for):
$ whois www.pearson.com
Whois Server Version 2.0
Domain names in the .com and .net domains can now be registered
with many different competing registrars. Go to http://www.internic.net
for detailed information.
No match for 'WWW.PEARSON.COM'.
Configuring a Local Caching Nameserver
A caching nameserver builds a local cache of resolved domain names and provides them to other hosts on your LAN. This speeds up DNS searches and saves bandwidth by reusing lookups for frequently accessed domains and is especially useful on a slow dialup connection or when your ISP's own nameservers malfunction.
If you have BIND and BIND-utils installed on your computer, you can configure a caching nameserver by installing the caching-nameserver package. This sets up the /etc/named.conf configuration file, the /var/named directory, and the configuration files in /var/named (localhost.zone, named.ca, and named.local).
To start the caching nameserver, you can start the named service manually (see Chapter 11, 'Automating Tasks') or use the system-config-services GUI configuration tool. Choose the Services menu option in the Server Settings menu, which is in the System Settings menu, and then select named and click the Start button.
To get your local computer to use the caching nameserver, reconfigure the /etc/resolv.conf file to comment out any references to your ISP's nameservers, and set the only nameserver to be the localhost (127.0.0.1). The /etc/resolv.conf for the caching nameserver host is as follows:
#/etc/resolv.conf
#nameserver 83.64.1.10
#nameserver 83.64.0.10
nameserver 127.0.0.1
Other machines on your network should have the IP of the local caching nameserver in their /etc/resolv.conf files. Assuming that the IP address for the computer running the caching nameserver is 192.168.1.5, the /etc/resolv.conf files on the other machines on your network should be the following:
