Planning and Enabling SLP (Tasks)
This chapter provides information on planning and enabling SLP. The following sections discuss SLP configuration and the process for enabling SLP.
SLP Configuration Considerations
The SLP daemon is preconfigured with default properties for installation with the Solaris 9 operating environment. If your enterprise functions well with default settings, the SLP deployment requires virtually no administration.
In some situations, however, you might want to modify the SLP properties to tune network operations or to activate certain features. With a few configuration changes you can enable SLP logging, for example. The information in a SLP log and in snoop traces can then help you decide if additional configuration is necessary.
SLP configuration properties reside in the slp.conf file, which is located in the /etc/inet directory. If you decide to change the default property settings, refer to Chapter 20, Administering SLP (Tasks) for the appropriate procedures.
Before you modify SLP configuration settings, consider the following questions that are related to key aspects of network administration:
What network technologies are operating in the enterprise?
How much network traffic can the technologies handle smoothly?
How many services, of what type, are available on the network?
How many users are on the network? What services do they require? Where are users located in relation to their most frequently accessed services?
Deciding What to Reconfigure
You can use the SLP-enabled snoop utility and SLP logging utilities to decide if reconfiguration is necessary and what properties you need to modify. For example, you might reconfigure certain properties to do the following:
Accommodate a mix of network media that have varying latencies and bandwidth characteristics
Recover the enterprise from network failures or unplanned partitioning
Add DAs to reduce proliferation of SLP multicasts
Implement new scopes to organize users with their most frequently accessed services
Using snoop to Monitor SLP Activity
The snoop utility is a passive administrative tool that provides network traffic information. The utility itself generates minimal traffic and enables you to watch all activity on your network as it occurs.
The snoop utility provides traces of the actual SLP message traffic. For example, when you run snoop with the slp command-line argument, the utility displays traces with information on SLP registrations and deregistrations. You can use the information to gauge the network load by checking which services are being registered and how much reregistration activity its occurring.
The snoop utility is also useful for observing the traffic flow between SLP hosts in your enterprise. When you run snoop with the slp command-line argument, you can monitor the following types of SLP activity to determine if network or agent reconfiguration is needed:
The number of hosts that are using a particular DA. Use this information to decide whether to deploy additional DAs for load balancing.
The number of hosts that are using a particular DA. Use this information to help you determine whether to configure certain hosts with new or different scopes.
Whether UA requests a timeout or DA acknowledgment is slow. You can determine whether a DA is overloaded by monitoring UA timeouts and retransmissions. You can also check if the DA requires more than a few seconds to send registration acknowledgments to an SA. Use this information to rebalance the network load on the DA, if necessary, by deploying additional DAs or changing the scope configurations.
Using snoop with the -V (verbose) command-line argument, you can obtain registration lifetimes and value of the fresh flag in SrvReg to determine whether the number of reregistrations should be reduced.
You can also use snoop to trace other kinds of SLP traffic, such as the following:
Traffic between UA clients and DAs
Traffic between multicasting UA clients and replying SAs
For more information about snoop, refer to the snoop(1M).
Use the netstat command in conjunction with snoop to view traffic and congestion statistics. For more information about netstat, refer to netstat(1M).
How to Use snoop to Run SLP Traces
Run snoop with the slp command-line argument.
Brief Mode: # snoop slp
When you run snoop in the default brief mode, ongoing output is delivered to your screen. SLP messages are truncated to fit on one line per SLP trace.
Verbose Mode: # snoop -v slp
When you run snoop in verbose mode, snoop delivers ongoing, unabbreviated output to your screen, which provides the following information:
The complete address of the service URL
All service attributes
The registration lifetime
All security parameters and flags, if any are available