The service location protocol (SLP) was developed so that networking applications such as the Novell Client for Linux could discover the existence, location, and configuration of networked services in enterprise networks. Without SLP, users must supply the hostname or network address of the service that they want to access.
Because SLP makes the existence, location, and configuration of certain services known to all clients in the local network, the Novell Client for Linux can use the information distributed to simplify login. In the case of the Novell Client, having SLP set up allows users to see the trees, contexts, and servers available to them when they use the Novell Client for Linux Login screen. When they click the Browse button, a list of available trees, contexts, or servers appears and they can select the appropriate ones. For example, instead of remembering an IP address or DNS name for a server, users can select the server's name from a list of available servers.
SLP must be activated and set up on your Novell servers in order for the Novell Client to take advantage of it. For more information, see "SLP Services in the Network" in the SUSE LINUX Enterprise Server 9 Administration Guide.
SLP is not set up by default on Linux workstations. The Novell Client for Linux includes a Novell Client Configuration Wizard to simplify the process of configuring your SLP and other Novell Client configuration options. The Novell Client Configuration Wizard provides only basic SLP configuration because this is all that is required by the client. However, if other applications on your workstation require more advanced settings, you can modify the /etc/slp.conf file to set advanced settings.
For more information on advanced SLP configuration, see the OpenSLP Web site. In addition, the /usr/share/doc/packages/openslp directory contains documentation on SLP, including a README.SuSE file containing the SUSE® LINUX details, several RFCs, and two introductory HTML documents (An Introduction to SLP and OpenSLP User's Guide). RFC 2609 details the syntax of the service URLs used and RFC 2610 details DHCP via SLP.
Launch the Novell Client Configuration Wizard using either of the following methods:
Select Service Location Protocol (OpenSLP), then click Start Wizard.
Specify the following SLP information for your network:
Scope List: Specify the scopes a user agent (UA) or service agent (SA) is allowed when making requests or registering, or the scopes a directory agent (DA) must support.
Directory Agent List: Specify the specific DAs that UA and SA agents must use. If this setting is not used, dynamic DA discovery is used to determine which DAs to use.
Broadcast Only: Select this option to use broadcasting instead of multicasting. This setting is not usually necessary because OpenSLP automatically uses broadcasting if multicasting is unavailable.
SLP is designed to use IP multicasting; however, if any SLP Agent does not implement IP multicasting, then all Agents must use broadcasting to reach that Agent. If a DA does not support multicasting, we recommend using the Directory Agent List to configure that Directory Agent rather than using this option.
If the network does not contain a DA, IP servers must use their own SAs to specify the services that are available. If the SA does not support multicasting and if there are any services advertised by that SA that are needed by the UA on this machine, then use the Broadcast Only option.
Broadcasting has the disadvantage of being limited to the local LAN segment.
Maximum Results: Specify a 32-bit integer giving the maximum number of results to accumulate and return for a synchronous request before the time-out, or the maximum number of results to return through a callback if the request results are reported asynchronously.
Complete the Novell Client Configuration Wizard.
Restart the workstation.
If users cannot see a list of available trees, contexts, and servers when they use the Novell Client for Linux Login screen, use slptool, located in /usr/bin, to troubleshoot your SLP configuration.
After you start slpd (located in /usr/sbin), you should be able to issue a query for SLP service agents using the following command:
slptool findsrvs service:service-agent
This should display a list of the hosts that are running slpd, which indicates that OpenSLP is successfully installed and working. If you do not get a list, OpenSLP is not installed correctly or is not working. See Setting Up SLP for more information.