In concept, testing DNS/BIND servers consists of finding out where information you are looking for is located. In practice, testing DNS servers involves tracing through a network of servers and their databases back to the server responsible for the information. This section provides the tests you use to locate the information.
Appendix I contains a worksheet for you to record information from the various tests. On a copy of the worksheet, write the current server's name, current domain name, and target domain name.
The following terms are used in this section. Refer back to them as needed during the problem solving tests.
A server that stores the information that was requested locally. In contrast, a server that is not authoritative must ask other servers for information about the target host.
The server you are currently logged in to and running tests from.
The types of resource records in the DNS database
files.
See
named(8)
for a complete list and explanation.
A server
that can answer DNS queries from data in its databases and cache, whether
or not it is authoritative for the information.
Forwarder entries can be
in the
named.boot
file.
Nameserver records map a domain name to a system that serves the domain, and determine whether a system is familiar with the name servers for the authoritative domain. Nameserver records have the following form:
domain-name IN NS machine-name
On the left is the domain name; on the right is the name of the machine that services the domain.
A server that stores the main copy of a target domain's databases. If the target host's information is not in the primary server's databases, it does not exist.
A server that pulls a copy of the target domain's data from another server. In most cases, the data is pulled from a primary server. However, in some cases, the data is pulled from another secondary server.
Start of authority records mark the start of a zone of authority. They occur at the beginning of each master database file. SOA records have the following form:
domain-name
IN SOA
machine-name
The portion of the target host name that begins after the first period (.).
Host name you are trying to resolve. The target domain name is derived from the target host name.
To determine if the current server can resolve the target data, complete the following steps:
Determine whether the current server can access the target data. Use the following commands:
#nslookupDefault Server: host1.corp.com Address: 127.0.0.1>server localhostDefault Server: localhost.corp.com Address: 127.0.0.1>set timeout=45>set retry=2>target_host.target_domain.
If the
nslookup
command: |
Action: |
| Succeeds | Go to step 3. |
| Fails | If the first time, go to step 2. |
| If the second time, go to Section 15.3. |
Determine whether the
named
daemon is running
by using the following command:
#ps gax | grep named
If the
named
daemon is: |
Action: |
| Running | Go to step 1. |
| Not running | Start the daemon by using the
/sbin/init.d/named
start
command.
If the Internet name service started message appears,
go to step 1. |
| If the message is not displayed, this machine is not configured as a DNS server. Decide how the machine should be configured. See Section 6.3 for more information. |
Log in to the client system and use the
nslookup
command to try to access the target data.
If the
nslookup
command: |
Action: |
| Succeeds | STOP. The client can resolve the target data. |
| Fails | The server knows the information,
but is not transferring it to the client.
Log out from the client; restart
DNS on the server by using the
/sbin/init.d/named restart
command; log in to the client; and use the
nslookup
command.
If it cannot resolve the target data, you have the wrong server or the DNS
server is broken. |
To determine whether the current server is a primary server or a secondary server, complete the following steps:
Compare the target domain name with all domain names of the
primary and secondary entries in the
/etc/named.boot
file.
These entries have the following form:
primarydomain filesecondary domain [host host... ] file
When directed, record information in the
named.boot
file
section on the worksheet.
If a
named.boot
entry: |
And the first field is: | Action: |
| Matches the target domain name | Primary | Write the server type, domain name, and database file name on the worksheet and go to Section 15.7. |
| Secondary | Write the server type, domain name, database file name, and host IP addresses on the worksheet and go to Section 15.6. | |
| Is a subset of the target domain name | Primary | Write the server type, domain name, and database file name on the worksheet and go to step 2. |
| Secondary | Write the server type, domain name, database file name, and host IP addresses on the worksheet and go to step 2. | |
| Neither matches nor is a subset of the target domain name | Primary or secondary | Go to Section 15.4. |
In the following example, the target domain name is zz.bb.cc.:
#cat /etc/named.boot
.
.
.
primary aa.bb.cc. aa.bb.cc.db [1] primary cc. cc.db [2] secondary bb.cc. bb.cc.db [3] secondary zz.bb.cc. aa.bb.cc.db [4]
.
.
.
Not a subset of zz.bb.cc.. [Return to example]
A subset of zz.bb.cc.. The server is primary for cc. domain information and stores the information in the aa.bb.cc.db. file. [Return to example]
A subset of zz.bb.cc.. The server is secondary for bb.cc. domain information and stores the information in the file bb.cc.db. [Return to example]
An exact match of zz.bb.cc.. The server is secondary for zz.bb.cc. domain information and stores the information in the zz.bb.cc.db file. Since this is an exact match, you would go to Section 15.6 and perform additional tests. [Return to example]
Compare the target domain name with all nameserver (NS) records in the database file recorded on the worksheet. When directed, record information in the Nameservers section on the worksheet. Use the following commands to create and view a list of NS records:
#grep -n NS database_file > ns_list#grep -n ORIGIN database_file >> ns_list#sort -n ns_list > ns_list.srt#cat ns_list.srt
If any
NS
record: |
And the server is: | Action: |
| Contains a longer subset of the target domain name than the domain name on the worksheet | Primary or secondary | The server is neither primary or secondary for the target information. Write the names of the servers on the worksheet and go to step 3. |
| Does not contain a longer subset of the target domain name than the domain name on the worksheet | Primary | The database files contain the target information. Go to Section 15.7. |
| Secondary | The database files contain the target information. Go to Section 15.6. |
The following example shows the file created by the preceding commands. The target domain is zz.bb.cc. and the domain name from the worksheet is zz.bb.cc..
#cat ns_list.srt1:$ORIGIN cc. 10: IN NS server_1.cc. 17:$ORIGIN cc. 18:bb IN NS server_3.bb.cc. 21:$ORIGIN cc. 22:bb IN NS server_4.bb.cc. 41:$ORIGIN bb.cc. 42:zz IN NS server_5.zz.bb.cc. [1] 45:$ORIGIN bb.cc. 46:zz IN NS server_6.bb.cc. [2]
A longer subset (exact match) of the target domain. The domain name from the preceding $ORIGIN line, .bb.cc., is appended to the domain name of this line, zz, resulting in zz.bb.cc.. [Return to example]
A longer subset (exact match) of the target domain. The domain name from the preceding $ORIGIN line, .bb.cc., is appended to the domain name of this line, zz, resulting in zz.bb.cc.. [Return to example]
Find the IP addresses in the database file for any name servers on the worksheet. Use the following commands:
#grep -n ORIGIN database_file > ip_list#grep -n server_name database_file >> ip_list
.
.
.#sort -n ip_list > ip_list.srt#cat ip_list.srt
Write the IP addresses on the worksheet next to the corresponding server name and go to Section 15.4. The following example shows the file created by the preceding commands:
#cat ip_list.srt1:$ORIGIN cc. 17:$ORIGIN cc. 21:$ORIGIN cc. 41:$ORIGIN bb.cc. 42:zz IN NS server_5.zz.bb.cc. 43:$ORIGIN zz.bb.cc. 44:server_5 IN A 10.140.48.3 [1] 45:$ORIGIN bb.cc. 46:zz IN NS server_6.bb.cc. 47:$ORIGIN bb.cc. 48:server_6 IN A 10.12.48.3 [2]
The IP address for server_5. [Return to example]
The IP address for server_6. [Return to example]
To determine which servers the current server communicates with in order to get information for the target domain, complete the following steps:
Search the
named.boot
file and find any
forwarder lines.
Use the following command:
#grep forwarders /etc/namedb/named.boot
When directed, record information in the Forwarders section on the worksheet.
| If your system: | Action: |
| Contains a forwarder line | The current server forwards requests. Write the IP addresses for any forwarders on the worksheet and go to Section 15.5. |
| Does not contain a forwarder line | The current server does not forward queries. Go to step 2. |
Compare the target domain name with all nameserver (NS) records in the database file recorded on the worksheet. When directed, record information in the Nameserver section on the worksheet.
Use the following commands to create and view a list of NS records for each database file:
#grep -n NS database_file > ns_list#grep -n ORIGIN database_file >> ns_list#sort -n ns_list > ns_list.srt#cat ns_list.srt
| If any NS record: | And: | Action: |
| Contains a longer subset of the target domain name than the domain name on the worksheet | --> | Write the names of the servers on the worksheet and go to step 3. |
| Does not contain a longer subset of the target domain name than the domain name on the worksheet | The Nameserver section on the worksheet is blank | Go to Section 15.8. |
Find the IP addresses in the database file for any name servers on the worksheet. Use the following commands:
#grep -n ORIGIN database_file > ip_list#grep -n server_name database_file >> ip_list
.
.
.#sort -n ip_list > ip_list.srt#cat ip_list.srt
Write the IP addresses on the worksheet next to the corresponding server name and go to step 4.
Verify whether each server listed in the Nameserver section
on the worksheet is reachable by using the
ping
command.
| If a server: | And: | Action: |
Responds to the
ping
command |
You have root access to the server | The server is reachable and under your administrative control. Note both items on the worksheet. Go to step 5. |
| You do not have root access to the server | The server is reachable, but not under your administrative control. Note both items on the worksheet. Go to step 5. | |
Does not respond to the
ping
command |
--> | Note this on the worksheet. |
If no servers responded to
the
ping
command, STOP.
The current server is isolated
from its servers on the network.
You cannot solve the problem; contact your
enterprise network administrator. |
Log in to each reachable server by using the
telnet
command.
Each server you log in to becomes the current server.
Get a new worksheet and write the current server name, current domain name,
and target domain name on it.
Go to
Section 15.2.
To determine whether the forwarders prevent you from resolving the target host name, complete the following steps:
Determine whether each forwarder listed on the worksheet is
reachable by using the
ping
command.
| If a forwarder: | And: | Action: |
Responds to the
ping
command |
You have root access to the forwarder | The forwarder is reachable and under your administrative control. Note both items on the worksheet. Go to step 2. |
| You do not have root access to the forwarder | The forwarder is reachable, but not under your administrative control. Note both items on the worksheet. Go to step 2. | |
Does not respond to the
ping
command |
--> | Note this on the worksheet. |
If no forwarders responded
to the
ping
command, STOP.
The current server is isolated
from its forwarders on the network.
You cannot solve the problem; contact
your enterprise network administrator. |
Edit the
named.boot
file and eliminate
any forwarders that did not respond to the
ping
command.
Enter the
nslookup
command again for the
target host.
If the
nslookup
command: |
Action: |
| Succeeds | Go to step 4. |
| Fails | Go to step 5. |
Edit the
named.boot
file and add the forwarders
removed in step 2 at the end of the forwarders line.
In addition, contact
the administrators of forwarders not under your administrative control and
inform them that they might have a problem with their forwarder.
STOP.
Log in to each reachable forwarder by using the
telnet
command.
This forwarder is now the current server.
On a new
worksheet, write the current server name, current domain name, and target
domain name.
Go to
Section 15.2.
| If the forwarder or other machines: | Action: |
| Cannot resolve the target name | Remove the forwarder from
named.boot
file. |
| Can resolve the target name | STOP. |
To determine whether the secondary server has the information you want, complete the following steps:
Find the database serial number in the start of authority record in the database file. Use the following command:
#head -4 database_file
Write the first number on the worksheet in the
named.boot
section.
This is the serial number.
If you have a serial number on a previous
worksheet, compare the current serial number with that one.
If the current
number is larger, write "newer" on the worksheet.
If it is smaller, write
"older." In the following example, 23 is the serial number:
#head -4 database_file$ORIGIN cc. bb IN SOA host1.bb.cc. postmaster.host1.bb.cc. ( 23 300 60 1209600 43200 ) IN MX 100 host1.bb.cc.
Determine whether the target data is contained in the database file written on the worksheet. Use the following commands to create and view a list of resource records:
#grep -n data_type database_file > ns_list#grep -n ORIGIN database_file >> ns_list#sort -n ns_list > ns_list.srt#cat ns_list.srt
| If the database file: | And the serial number is: | Action: |
| Contains the target data | Newer | The data exists in the domain. Go to step 3. |
| Contains the target data | Older or same | The server is broken or you made a mistake. Recheck all steps up to this point. |
| Does not contain the target data | --> | The data does not exist in the domain. Go to step 4. |
Determine whether the current server can access the target data. Use the following commands:
#nslookupDefault Server: host1.corp.com Address: 127.0.0.1>server localhostDefault Server: localhost.corp.com Address: 127.0.0.1>set timeout=45>set retry=2>target_host.target_domain.
If the
nslookup
command: |
And the database serial number is: | Action: |
| Succeeds | --> | STOP. The server is working. Either the client or server cannot communicate with this server or this server just started working. |
| Succeeds | Newer | Log out of the secondary server. Get the previous secondary server's worksheet and go to step 8. |
| Fails | --> | Restart the current secondary server by using
the
/sbin/init.d/named
restart command.
Then reenter the
nslookup
command. |
Verify whether each name server listed on the worksheet is
reachable by using the
ping
command.
| If a server: | And: | Action: |
Responds to the
ping
command |
You have root access to the server | The server is reachable and under your administrative control. Note both items on the worksheet. |
| You do not have root access to the server | The server is reachable, but not under your administrative control. Note both items on the worksheet. | |
Does not respond to the
ping
command |
--> | Note this on the worksheet. |
If no servers responded to
the
ping
command, STOP.
The current server is isolated
from its servers on the network.
You cannot solve the problem; contact your
enterprise network administrator. |
Count the number of servers that responded to the
ping
command and that are under your administrative control.
If the number is zero
(0), go to
Section 15.9.
Edit the
named.boot
file and find the
secondary
entry.
Delete the IP address for those servers that are
not reachable and are not under your administrative control.
Delete those
entries from the worksheet as well.
Log in to each reachable server by using the
telnet
command.
Start a new worksheet for each server, writing the server
name as the current server.
Save the old worksheet.
Compare the target domain name with all domain names of the
primary and secondary entries in the
/etc/named.boot
file.
These entries have the following form:
primarydomain filesecondary domain [host host ...] file
When directed, record information in the
named.boot
file section on the worksheet.
If a
named.boot
entry: |
And the first field is: | Action: |
| Matches the target domain name | Primary | Write the domain name and database file name on the worksheet and go to Section 15.7. |
| Secondary | Write the domain name, host IP addresses, and the database file name on the worksheet and go to step 1. | |
| Is a subset of the target domain name | --> | STOP. |
| Neither matches nor is a subset of the target domain name | --> | STOP. |
Restart the current secondary server by using the following command:
#/sbin/init.d/named restart
After restarting, wait a few minutes before proceeding to the next step. This allows time for the database to be updated.
Determine whether the current server can access the target data. Use the following commands:
#nslookupDefault Server: host1.corp.com Address: 127.0.0.1>server localhostDefault Server: localhost.corp.com Address: 127.0.0.1>set timeout=45>set retry=2>target_host.target_domain.
If the
nslookup
command: |
Action: |
| Succeeds | STOP.
If you are in a
telnet
session to another secondary server, log out.
Go to step 8. |
| Fails | If you just ended a
telnet
session to another server, go to step 10. |
If you did not end a
telnet
session, either the current server is broken and cannot read
the database file or you made an error.
Check all steps up to this point. |
Compare the database serial number of the current server with the database serial number of the server from which you just logged out. Use the following command:
#head -4 database_file
| If the current database serial number is: | Action: |
| Older | Either the server cannot pull the database from the authoritative server or you made a mistake. Check all steps up to this point. |
| The same | The serial numbers cannot be equal. Check all steps up to this point. |
To determine whether the primary server has the information you want, complete the following steps:
If you are in a
telnet
session from a secondary
server to a primary server, go to step 2.
Otherwise, go to step 3.
Find the database serial number in the start of authority record in the database file. Use the following command:
#head -4 database_file
Write the first number on the worksheet in the
named.boot
section.
This is the serial number.
If you have a serial number of a previous
worksheet, compare the current version number with that one.
If the current
number is larger, write "newer" on the worksheet.
If it is smaller, write
"older." If it is equal, write "same." In the following example, 23 is the
serial number:
#head -4 database_file$ORIGIN cc. bb IN SOA host1.bb.cc. postmaster.host1.bb.cc. ( 23 300 60 1209600 43200 ) IN MX 100 host1.bb.cc.
Determine whether the target data is contained in the database file written on the worksheet. Use the following commands to create and view a list of resource records:
#grep -n data_type database_file > ns_list#grep -n ORIGIN database_file >> ns_list#sort -n ns_list > ns_list.srt#cat ns_list.srt
| If the database file: | Action: |
| Contains the target data | The data exists in the domain. Go to step 4. |
| Does not contain the target data | The data does not exist in the domain. Go to step 5. |
Determine whether the current server can access the target data. Use the following commands:
#nslookupDefault Server: host1.corp.com Address: 127.0.0.1>server localhostDefault Server: localhost.corp.com Address: 127.0.0.1>set timeout=45>set retry=2>target_host.target_domain.
If the
nslookup
command: |
And the database serial number is: | Action: |
| Succeeds | --> | STOP. The server is working. Either the last server cannot communicate with this server or this server just started working. |
| Succeeds | Older or same | STOP. The server is broken or you made a mistake. Check all steps up to this point. |
| Succeeds | Newer | Log out of the primary server. Get the previous secondary server's worksheet and go to Section 15.6, step 8. |
| Fails | --> | Restart the current primary server by using
the
/sbin/init.d/named
restart command.
Then reenter the
nslookup
command. |
Edit the database file and increment the database serial number by 1 to age the database. The following example shows the SOA record before and after editing. Note the serial number increase from 23 to 24.
#head -4 database_file$ORIGIN cc. bb IN SOA host1.bb.cc. postmaster.host1.bb.cc. ( 23 300 60 1209600 43200 ) IN MX 100 host1.bb.cc.#vi database_file
.
.
.#head -4 database_file$ORIGIN cc. bb IN SOA host1.bb.cc. postmaster.host1.bb.cc. ( 24 300 60 1209600 43200 ) IN MX 100 host1.bb.cc.
Edit the database file and add new data to the database.
Refer
to
Section 15.1
for information on valid data types.
Database
fields are separated by a tab character.
Be sure to precede any new entry
with a
$ORIGIN
entry.
The following example shows a new
address record for host host1.bb.cc:
$ORIGIN bb.cc host1 IN A 16.141.112.11
Restart the primary server by using the following command:
#/sbin/init.d/named restart
Determine whether the current server can access the target data. Use the following commands:
#nslookupDefault Server: host1.corp.com Address: 127.0.0.1>server localhostDefault Server: localhost.corp.com Address: 127.0.0.1>set timeout=45>set retry=2>target_host.target_domain.
If the
nslookup
command: |
Action: |
| Succeeds | Log out of the primary server. Get the previous secondary server's worksheet and go to Section 15.6, step 8. |
| Fails | Either the server is broken or you made a mistake. Check all steps up to this point. |
To resolve the target name beginning with the root of the DNS namespace, complete the following steps:
Determine whether the current server has a cache file containing the information necessary to find a root server. Use the following command:
#grep cache /etc/named.boot
| If a cache line: | Action: |
| Does not exist | The current server cannot contact a root name server. Note this on the worksheet and go to step 2. |
| Exists | Note this on the worksheet and go to step 3. |
Add a cache file to your server.
Caution
This step alters many system files. Perform the steps as shown to ensure the correct operation of your system.
Create copies of specific DNS and system files. Enter the following commands:
#cd /etc#cp -r namedb namedb.back#cp rc.config rc.config.back#cp hosts hosts.back#cp resolv.conf resolv.conf.back#cp svc.conf svc.conf.back#cd /var/adm/sendmail#cp sendmail.cf sendmail.cf.back
Display the name of the local host by using the
hostname
command.
You will need to set the host name again after
running the BIND Configuration application.
Run the BIND Configuration application.
(See
Section 6.3.)
Modify the configuration and create a caching server.
Do not start the DNS
daemon automatically and do not run
svcsetup.
Copy the system files back to the
/etc
directory.
Use the following commands:
#cd /etc#cp rc.config.back rc.config#cp hosts.back hosts#cp resolv.conf.back resolv.conf#cp svc.conf.back svc.conf
Set the host name back to the original host name by using
the
hostname
command.
Copy the
sendmail
file back to the
/var/adm/sendmail
directory and restart
sendmail.
#cd /var/adm/sendmail#cp sendmail.cf.back sendmail.cf#/sbin/init.d/sendmail restart
Copy the DNS files back to the
/etc
directory.
Use the following commands:
#cd /etc#cp namedb/namedb.boot namedb.back/named.boot_new#cp namedb/namedb.ca namedb.back#rm -rf namedb.back namedb#mv namedb.back namedb#cd namedb
Edit the
named.boot
file and add the following
two lines to the end of the file:
; cache . named.ca
Remove the
named.boot_new
file.
Restart the current server by using the
/sbin/init.d/named restart
command.
Display the
named.ca
file by using the
following command:
#cat named.ca
Write the root name server names and their IP addresses in the Root nameservers section on the worksheet.
Verify whether each root name server listed on the worksheet
is reachable by using the
ping
command.
| If a root name server: | Action: |
Responds to the
ping
command |
Note this on the worksheet. Go to Section 15.10. |
Does not respond to the
ping
command |
Note this on the worksheet.
If no servers
responded to the
ping
command, go to step 5. |
Do either of the following:
Give the current server access to the Internet.
Then restart
the
named
daemon by using the following command:
#/sbin/init.d/named restart
Keep the same current server and worksheet, and go to Section 15.2.
Add a forwarder entry to direct the current server to communicate
with a machine with access to the Internet.
Then restart the
named
daemon by using the following command:
#/sbin/init.d/named restart
Keep the same current server and worksheet, and go to Section 15.2.
To resolve target data using a name server, complete the following steps:
Enter the
nslookup
command for the target
system.
Choose the first name server from either the Root nameserver section
or the Nameserver section.
Use the following commands:
current_server>nslookupDefault Server: localhost.zk3.dec.com Address: 127.0.0.1>server IP_addressDefault Server: [IP_address]Address: 128.102.16.10>set type data_type>target_name
If the
nslookup
command: |
And: | Action: |
| Succeeds | --> | STOP. The server is working. Either the last server you checked out does not talk to this one or this server just started working. Recheck all steps completed up to this point. |
| Fails | An error message is returned | If a "non-existent domain" message is displayed, no data exists for the target_name. Go to Section Section 15.10. |
| If a "no information available" message is displayed, the target_name exists, but the information you want is not associated with it. If this information should exist, contact the target domain administrator. | ||
| If a "timed-out" message is displayed, the server to which you sent the query cannot contact the server that knows the information. Go to step 2. | ||
| Fails | An error message is not returned | An unknown error. Contact the target domain administrator. |
Modify the retry and timeout values and enter the
nslookup
command again.
Enter the following commands:
current_server>nslookupDefault Server: localhost.zk3.dec.com Address: 127.0.0.1>server IP_addressDefault Server: [IP_address]Address:IP_address>set type data_type>target_name
If the
nslookup
command: |
And: | Action: |
| Succeeds | --> | STOP. The server is working, but is slow. This might prevent the query from being resolved. Check the network connection to the server. If that is correct, wait for the performance to improve. If it does not improve, contact the name server administrator. |
| Fails | An error message is returned | If a "non-existent domain" message is displayed, no data exists for the target_name. Go to Section 15.10. |
| If a no information available message is displayed, the target_name exists, but the information you want is not associated with it. If this information should exist, contact the target domain administrator. | ||
| If a "timed-out" message is displayed, the server to which you sent the query cannot access the server that knows the information. Select another name server from the worksheet and go to step 1. | ||
| Fails | An error message is not returned | An unknown error. Contact the target domain administrator. |
To find the first nonexistent domain in a target name, complete the following steps:
Enter the
nslookup
command, using the smallest
subset of the target domain name.
Enter the following commands:
current_server>nslookupDefault Server: localhost.zk3.dec.com Address: 127.0.0.1>server IP_addressDefault Server: [IP_address]Address:IP_address>set type=ns>target_name_subset
For example, if the target domain name is zz.bb.cc., the first attempt is to resolve the target name subset cc.. If necessary, the second attempt uses bb.cc., and the third, zz.bb.cc..
If the
nslookup
command: |
And: | Action: |
| Succeeds | --> | Go to step 3. |
| Fails | An error message is returned | If a "non-existent domain" message is displayed, no data exists for the target_name. If the information should exist, contact the domain administrator and request that the information be added to the domain. STOP. |
| If a "timed-out" message is displayed, go to step 2. This should not happen because the server worked well before. |
Modify the retry and timeout values and enter the
nslookup
command again.
Enter the following commands:
current_server>nslookupDefault Server: localhost.zk3.dec.com Address: 127.0.0.1>server IP_addressDefault Server: [IP_address]Address:IP_address>set retry=2>set timeout=45>set type=ns>target_name_subset
If the
nslookup
command: |
And: | Action: |
| Succeeds | --> | Go to step 3. |
| Fails | An error message is returned | If a "non-existent domain" message is displayed, no data exists for the target_name. If the information should exist, contact the domain administrator and request that the information be added to the domain. STOP. |
| If a "timed-out" message is displayed, select another name server from the worksheet and go to Section 15.9. |
Add the next part of the target domain name to the target subset and go to step 1.