HP-UX IP Address and Client Management Administrator's Guide HP-UX 11i v2, HP-UX 11i v3

The slpd Daemon
The slpd daemon process acts as either a DA or an SA server. Service processes on a host register
their service advertisements with slpd. These service processes contain an SA client library that
communicates with slpd, acting as the SA server. slpd forwards all service registrations and
withdrawals to DAs and times out invalid or expired service advertisements.
The SLP library (libslp.sl) provides the UA functionality on a per-process basis without the
need to communicate with slpd running on local machines. This means that in certain cases,
you do not have to load the SLP daemon on every machine. This helps to minimize the overhead
for SLP for those machines that need only UA capabilities.
slpd must be running on all the machines that need to register services. In other words, slpd
is required on all machines that run applications and make calls to either SLPReg()
orSLPDeReg() APIs.
slpd accepts registration requests for services from SAs and maintains this information internally.
It shares this information with clients represented by their UAs when queried. In addition, slpd
allows older applications that are not SLP-enabled to advertise the services offered by them. You
can use the -r option to specify the file that contains static registrations. By default, slpd reads
static registrations from the file /etc/slp.reg.
You need to run slpd in order to make the registrations for the /etc/slp.reg file available
to other machines. Additionally, slpd must be running for automatic DA and scope discovery
to work correctly. If slpd is not running, then DAs and scopes can be discovered only via DHCP
or the /etc/slp.conf file.
NOTE: In the absence of a standard DHCP API, discovery via DHCP is currently not supported.
slpd is not required if a machine requests only services. In other words, slpd is not required
on machines if a call is never made to SLPReg() or SLPDeReg(). Additionally, slpd is not
needed on a machine if either manual or DHCP type of DA or scope discovery is sufficient.
Startup Options
You can invoke slpd with various options. Run the following command on the command line
to invoke slpd:
slp [-d] [-c config file] [-r registration
file] [-l log file] [-p pid file]
Table 1-23 contains the list of command-line options that SLP supports at startup.
Table 1-23 Startup Options
DescriptionOption
Prevents detaching from the controlling tty.[-d]
Specifies the file that slpd uses to read configuration information. The default
configuration file is /etc/slp.conf.
[-c config file]
Specifies the file that slpd reads to obtain static registrations. The default
registration file is /etc/slp.reg.
[-r registration file]
Specifies the file that receives slpd log messages. The default log file is
/var/log/slpd.log.
[-l log file]
Specifies the file that holds the slpd process ID. The default pid file is
/var/run/slpd.pid.
[-p pid file]
You can use the slpdc script to start, stop, and restart slpdcand also to dump the database.
Table 1-24 contains the list of commands that slpdc supports.
SLP Overview 59