Configuring and Managing MPE/iX Internet Services (August 2002)

Chapter 8
DNS BIND/iX
Data Files
129
G.ROOT-SERVERS.NET 99999999 IN A 192.112.36.4
H.ROOT-SERVERS.NET 99999999 IN A 128.63.2.53
I.ROOT-SERVERS.NET 99999999 IN A 192.36.148.17
Here, the dot (.) refers to the root domain and the 99999999 means a very long time-to-live value. The TTL
value is no longer used for caching because the data isn’t discarded if it times out, but administrators
generally keep it around because it does no harm.
Your site may not have access to the Internet or may have protected its connection via a firewall. Often in this
type of DNS configuration, one or more machines will be designated as a root server. In this case, the cache
file will contain a list of internal root servers, and not the official Internet master root domain servers.
Testing Your Name Server
Perform simple checks on your name server’s health with nslookup. This utility is standard with every
TCP/IP-network-aware version of UNIX. There are other similar tools available — see “List of Utilities” later
in this section for details.
You can find the source code for dig at several anonymous FTP archive sites, including:
ftp://ftp.wonderland.org/NetBSD/NetBSD-current/src/usr.sbin/named/dig/ for the NetBSD release.
Use Archie to find other sites.
The nslookup utility can be used interactively, much like other programs, such as ftp. That is, if you invoke
this program without command line arguments, it displays a prompt and waits for your command:
>server mpe3000
Default Name Server: mpe3000.cup.hp.com Address: 15.13.199.80
By default, nslookup performs queries based on host names you submit; just enter a host name after the
prompt:
> romeo
Server: mpe3000.cup.hp.com
Address: 15.13.199.80
Name: romeo.cup.hp.com
Address: 15.13.194.242
> 15.12.194.242
Server: mpe3000.cup.hp.com
Address: 15.13.199.80
Name: romeo.cup.hp.com
Address: 15.12.194.242
You can check the resource records information about name server:
> set type=ns
> mpeworld
Name Server: mpeworld.cup.hp.com
Address: 15.13.199.80
origin = dns.cup.hp.com
mail addr = dns-admin.dns.cup.hp.com
serial = 96092255
refresh = 10800 (3 hours)
retry = 3600 (1 hour) expire = 604800 (7 days)
minimum ttl = 86400 (1 day)