9.4 Service Location Protocol (SLP)

SLP is not a migratable service, however, it is a critical component of OES 2 and must be planned as part of your upgrade strategy.

9.4.1 About SLP in OES 2

SLP lets network services register their availability on the network. SLP agents then keep track of which services are available and provide that information to applications that need it, such as the Novell Client™.

For example, without an advertisement or discovery mechanism like SLP, users must know the IP address or DNS name of a server hosting the tree in order to log in and use network services. Without SLP, browsing for trees on the network would not be possible.

9.4.2 Platform Differences in SLP Services

SLP on NetWare

NetWare uses a Novell customized version of SLP called Novell SLP that provides an additional agent type, the Directory Agent or DA, which can synchronize information between DAs.

On NetWare, SLP services are integrated with and configured to automatically work with eDirectory and other services; if eDirectory is configured correctly, the services work without SLP.

If you have a NetWare tree, you automatically have Novell SLP on your network and you can continue to use it as the SLP service during your upgrade to OES 2.

The Novell version of SLP takes certain liberties with the SLP standard in order to provide a more robust service advertising environment, but it does so at the expense of some scalability. For a discussion of SLP and OpenSLP and references to documents essential to understanding the protocol, refer to Configuring OpenSLP for eDirectory in the Novell eDirectory 8.8 Installation Guide.

SLP on OES 2 SP3

Novell provides a basic level of SLP support when eDirectory is installed on an OES server. OES servers are configured with an SA that registers SLP-aware applications (such as eDirectory) with the server.

However, you should configure OpenSLP (the default SLP service for OES), especially if you are installing more than three servers in a replica ring or eDirectory partition. The first three servers in a replica ring or eDirectory partition have an eDirectory replica installed automatically. The fourth and subsequently installed servers in a replica ring or eDirectory partition must have SLP configured for all services to work properly.

Caveats

  • DA synchronization is not part of OpenSLP.

  • If you are running NetWare 5.1 in your tree, it must be at SP8 to have SLP version 2 functionality. Older versions are not compatible with OpenSLP running on OES 2.

  • If your workstations can connect to the server using its IP address but not its DNS name, you need to update to Novell Client 4.91 SP5 or later. See TID 3890003.

9.4.3 Setting Up SLP on OES 2

Enabling Multicasting

SLP relies on multicasting; however, most Linux systems are not configured, by default, to provide multicast support. Enter the following at the shell prompt to determine whether multicasting is supported:

route -n 

If multicasting is supported, you see an entry in the routing table for the 224.0.0.0 destination.

If not:

  1. Open a terminal session.

  2. Change to the root user account.

  3. At the shell prompt, enter the following command:

    route add -net 224.0.0.0 netmask 240.0.0.0 dev interface 
    

    (eth0 is usually the interface parameter)

  4. Verify that the route has been added by entering route -n at the shell prompt.

Installing and Configuring OpenSLP

Open SLP is available as an RPM and provides UA, SA. and DA functionality. You can download a copy from http://www.openslp.org./, It is also included with SLES 10 SP1.

OpenSLP installs like any other RPM by using the rpm -i command. The slpd daemon is installed in the /usr/sbin directory on the server.

After it is installed, you can configure the slpd daemon by editing the /etc/slp.conf file.

  • To configure the daemon to run every time the server is booted, use the following command:

    chkconfig slpd 345 
    
  • To configure an OES 2 server as a DA, edit the Static Scope and DA Configuration portion of the file.

  • To run the daemon, enter slpd at the shell prompt.

For additional OpenSLP setup instructions, see Setting Up OpenSLP on OES 2 Networks in the OES 2 SP3: Planning and Implementation Guide.