slp - Service Location Protocol
The Service Location Protocol (SLP) is a dynamic service
discovery protocol that runs on top of the Internet Protocol
(IP). The protocol is specified by the IETF standard-track
documents RFC 2165, RFC 2608, RFC 2609; the API is docu-
mented in RFC 2614. .
There are two components to the SLP technology. The first is
a daemon, slpd(1M), which coordinates SLP operations. The
second is a software library, slp_api(3slp), through which
processes access a public API. Both components are config-
ured by means of the SLP configuration file, slp.conf(4).
The SLP API is useful for two types of processes:
Services and service information can be requested
from the API. Clients do not need to know the
location of a required service, only the type of
service, and optionally, the service characteris-
tics. SLP will supply the location and other
information to the client through the API.
Programs that offer network services use the SLP
API to advertise their location as well as other
service information. The advertisement can
optionally include attributes describing the ser-
vice. Advertisements are accompanied by a life-
time; when the lifetime expires, the advertise-
ment is flushed, unless it is refreshed prior to
API libraries are available for both the C and Java
SLP provides the following additional features:
o slpd(1M) can be configured to function as a tran-
sparent directory agent. This feature makes SLP scal-
able to the enterprise. System administrators can con-
figure directory agents to achieve a number of dif-
ferent strategies for scalability.
o SLP service advertising and discovery is performed in
scopes. Unless otherwise configured, all discovery and
all advertisements are in the scope default. In the
case of a larger network, scopes can be used to group
services and client systems so that users will only
find those services which are physically near them,
belong to their department, or satisfy the specified
criteria. Administrators can configure these scopes
to achieve different service provider strategies.
o Services may be registered by proxy through a serial-
ized registration file. This is an alternative to
registering services through the API. See slpd.reg(4)
for more information.
for descriptions of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| Availability | SUNWslpu |
| CSI | CSI-enabled |
| Interface Stability | Standard |
| MT-Level | MT-Safe |
slpd(1m), slp_api(3slp), slp.conf(4), slpd.reg(4), attri-
Guttman, E., Perkins, C., Veizades, J., and Day, M., RFC
2608, Service Location Protocol, Version 2, The Internet
Society, June 1999.
Guttman, E., Perkins, C., and Kempf, J., RFC 2609, Service
Templates and Service: Schemes, The Internet Society, June
Kempf, J. and Guttman, E., RFC 2614, An API for Service
Location, The Internet Society, June 1999.
Veizades, J., Guttman, E., Perkins, C., and Kaplan, S., RFC
2165, Service Location Protocol, Network Working Group,
Man(1) output converted with