Configuring name service, NIS, and NTP clients

Configuring name service, NIS, and NTP clients

In UnixWare, the Client Manager allows you to set up a host as a client of several TCP/IP networking services including DNS name service, NIS information service, and NTP time service.

See also:

The Client Manager interface

If you are logged in as the network administrator or the system administrator, you can start the Client Manager in any of these ways:

Start the SCOadmin launcher by entering scoadmin on the command line, and then select Networking Client Manager.
Enter scoadmin Client Manager on the command line.

For more information on using SCOadmin managers, see ``Administering your system with SCOadmin''.

For convenience, the Client Manager displays the hostname and Internet domain name for the host being configured.

With the Client Manager, you can:

Configure name service using one or more of the following methods:
- Domain Name System (DNS)
- the /etc/hosts file
- Network Information Service (NIS)
Configure the order in which the configured name services will be tried when the client wants to resolve domain names and IP addresses.
Configure a Network Information Service (NIS) client
Configure a Network Time Protocol (NTP) client

The Client Manager also provides a graphical interface to the following networking tools: finger, nslookup, ping, traceroute, and whois.

Configuring a DNS client

To configure a DNS client using the Client Manager:

If the host is not already configured as a DNS client, select Services Add DNS.
If the host is already configured as a DNS client, click on DNS Client in the services listed, and then select Services Modify.
Enter the following details for the host:

Local domain
The fully qualified name for the domain that the host is in, for example, mynet.COM. If you do not specify a domain search order, the domain name will be appended when looking up a name which does not contain a dot.

Domain search order
Enter a list of up to six domains that you want DNS to search if you specify a hostname without appending a domain name. For each domain you enter, click on Add to add it to the list. You should normally include the local domain in this list. DNS will search the domains for a hostname in the order that you specify them in the list.
To change the position of a selected item in the list, click on Promote or Demote.

Name server search order
Enter a list of up to three DNS name servers, specified by their IP addresses, that the client can query. For each name server you enter, click on Add to add it to the list. If the host you are configuring is itself already configured as a DNS name server, place it at the top of the list by specifying it first using the loopback IP address (127.0.0.1). The resolver will query each name server in the order that you specify them in the list until it gets an answer.
To change the position of a selected item in the list, click on Promote or Demote.
Click on OK to exit.

NOTE: This procedure modifies the file /etc/resolv.conf. See resolv.conf(4tcp) for a description of the format of this file.

Configuring the /etc/hosts file

To configure name service on a client using the /etc/hosts file:

If the /etc/hosts file does not already exist, select Services Add Hosts database in the Client Manager.
If the /etc/hosts file does already exist, click on /etc/hosts file in the services listed in the Client Manager, and then select Services Modify.
To add an entry to the /etc/hosts file, click on Add, enter the IP address, hostname, and any alias names, then click on OK.
To modify an entry in the /etc/hosts file, click on it in the list to select it, and then click on Modify. Click on OK to save your changes.
To delete an entry in the /etc/hosts file, click on it in the list to select it, and then click on Delete.
Click on OK to exit.

NOTE: This procedure modifies the file /etc/hosts. See hosts(4tcp) for a description of the format of this file.

Entries for the host, including the loopback address, cannot be modified to prevent accidental deletion.

Configuring an NIS client

To configure an NIS client:

If you want the client to obtain password and group information from NIS servers, use an editor to remove the entries for non-local users and groups from /etc/passwd and /etc/group on the client, and add the following single line entry to the end of both files:
```
+:
```
Variations other than this simple entry are possible with /etc/passwd. See ``Preparing /etc/passwd'' for details.
WARNING: Do not remove entries for local accounts and groups such as root, bin, and sys. The system must be able to locate these entries at times when NIS service may be unavailable.
For more information about configuring other files on a NIS client, see ``Preparing files on NIS clients''.
If the host is not configured as an NIS client, select Services Add NIS in the Client Manager.
If the host is already configured as an NIS client, click on NIS client in the services listed in the Client Manager, and then select Services Modify.
Enter the name of the NIS domain. Note that this is not necessarily the same as the domain name used by DNS.
Select whether you want the client to be able to find a NIS server by broadcasting. This allows the client to bind to any server on the local subnet provided that it serves the same NIS domain.
Enter an optional list of IP addresses or domain names for the NIS servers to which the client can bind. These servers need not be on the local subnet but they must be in the same NIS domain. For each server, click on Add to add it to the list.
NOTE: The domain names entered for the NIS servers must be resolvable to IP addresses using entries in the client's /etc/hosts file or using DNS.
Click on OK to exit.

NOTE: This procedure modifies the files /etc/inet/nis.conf and /var/yp/binding/domainname/ypservers.

See also:

``Setting up NIS clients for broadcasting''

Configuring name service resolution order

To configure the order of the name services that a client will use for resolving domain names and IP addresses:

Select Services Name resolution order in the Client Manager.
Select a service from the Available services list, and click on Add to add it to the Configured services list.
To remove a configured service, select it from the Configured services list, and click on Remove.
The list of configured services is in the order in which they will be tried when a client tries to resolve a hostname or IP address. If necessary, use Promote and Demote to change the order of the services. The default order is NIS, /etc/hosts, and DNS.
Click on OK to exit.

NOTE: This procedure modifies the file /etc/netconfig. See netconfig(4bnu) for a description of the format of this file.

Some client applications may choose to ignore the specified order, and use their preferred method for name resolution instead.

Configuring an NTP client

To configure an NTP client using the Client Manager:

If the host is not already configured as an NTP client, select Services Add NTP.
If the host is already configured as an NTP client, click on NTP client in the services listed, and then select Services Modify.
Select how you want the client to behave:

Listen for time broadcasts
The client will listen passively for, and attempt to synchronize with, NTP packets being broadcast by time servers on the local network.

Poll time servers for time
The client will actively poll the listed time servers for the time, and attempt to synchronize with them.
Enter the IP addresses or hostnames of each time server, and click on Add to add it to the list.

Set clock at boot time
If set to Yes, the client will attempt to synchronize its clock at boot time with the listed time servers. This is a ``step'' change rather than a gradual ``slewed'' change. If set to No, the client will not attempt to synchronize its clock at boot time.
Click on OK to exit.

NOTE: This procedure modifies the files /etc/inet/ntp.conf and /etc/inet/config. See xntpd(1Mtcp) and config(4tcp) for a description of the format of these files.

Deleting a client service

To remove the configuration for a service using the Client Manager:

Click on the service to be removed from those listed, and then select Services Delete.
Click on OK to confirm.

NOTE: It is not possible to remove the /etc/hosts file using the Client Manager. This is to prevent accidental deletion of the host's loopback address.

Using network tools

The Client Manager provides a graphical interface to the following commands:

finger to find out information about a user.
nslookup to find out an IP address from a hostname or a hostname from an IP address.
ping to see if a host is alive.
traceroute to trace the route taken by packets to reach a host.
whois to look up a name in the Internet user name directory service.

Finding information about a user

To find out more information about a user:

Select Tools Finger in the Client Manager.
Enter the name of the user and click on Finger. To interrupt the query, click on Stop.
Click on Close to exit.

See also:

finger(1tcp)

Looking up a hostname or an IP address

To look up the IP address corresponding to a hostname, or the hostname corresponding to an IP address:

Select Tools Host lookup in the Client Manager.
Enter the hostname or IP address of the host and click on Query. To interrupt the query, click on Stop.
Click on Close to exit.

See also:

nslookup(1Mtcp)

Pinging other network hosts

To see if another network host is alive:

Select Tools Ping in the Client Manager.
Enter the hostname or IP address of the host.
To change the interval in seconds between packets or the number of packets that will be sent, click on Options, change the default values and click on OK.
Click on Ping to start sending packets. To interrupt the sending of packets, click on Stop.
Click on Close to exit.

See also:

ping(1Mtcp)

Tracing the route taken by network packets

To trace the route that network packets take to reach a host:

Select Tools Trace route in the Client Manager.
Enter the hostname or IP address of the host.
To set various trace options, click on Options. To change the maximum time in seconds that your host will wait for a response, or to set the maximum number of hops before the trace will be terminated, click on Options, change the default values, and click on OK.
Click on Trace to start the trace. To interrupt the trace, click on Stop.
Click on Close to exit.

See also:

traceroute(1Mtcp)

Looking up a name in the Internet user name directory service

To find out more information about a user who has an entry in the Internet user name directory service:

Select Tools Whois in the Client Manager.
Enter the name of the user.
To change the whois server (default is rs.internic.net), click on Options, enter the new server name, and click on OK.
Click on Query to start the query. To interrupt the query, click on Stop.
Click on Close to exit.

See also:

whois(1tcp)