Service Agents - Novell EDIRECTORY 8.8 Installation Manual

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3. Checking with the local SA for a DA with the specified scope (and adding new addresses to
4. Querying DHCP for network-configured DA addresses that match the specified scope (and
5. Multicasting a DA discovery request on a well-known port (and adding new addresses to the
The specified scope is "default" if not specified. That is, if no scope is statically defined in the SLP
configuration file, and no scope is specified in the query, then the scope used is the word "default".
It should also be noted that eDirectory never specifies a scope in its registrations. That's not to say
the scope always used with eDirectory is "default." In fact, if there is a statically configured scope,
that scope becomes the default scope for all local UA requests and SA registrations in the absence
of a specified scope.

Service Agents

Service agents take the physical form of a separate process on the host machine. In the case of
Win32, slpd.exe runs as a service on the local machine. User agents query the local service agent
by sending messages to the loop-back address on a well-known port.
A service agent locates and caches directory agents and their supported scope list by sending a DA
discovery request directly to potential DA addresses by:
1. Checking all statically configured DA addresses (and adding new ones to the SA's known DA
2. Requesting a list of DA's and scopes from DHCP (and adding new ones to the SA's known
3. Multicasting a DA discovery request on a well-known port (and adding new ones to the SA's
4. Receiving DA advertising packets that are periodically broadcast by DAs (and adding new
Since a user agent always queries the local service agent first, this is important, as the local service
agent's response will determine whether or not the user agent continues to the next stage of
discovery (in this case DHCP-- see steps 3 and 4 in
Configuration Parameters
Certain configuration parameters in the %systemroot%/slp.conf file control DA discovery as well:
net.slp.useScopes = <comma delimited scope list>
net.slp.DAAddresses = <comma delimited address list>
net.slp.passiveDADetection = <"true" or "false">
net.slp.activeDADetection = <"true" or "false">
net.slp.DAActiveDiscoveryInterval = <0, 1, or a number of seconds>
The useScopes option indicates which scopes the SA will advertise into, and which scopes queries
will be made to in the absence of a specific scope on the registration or query made by the service
or client application. Because eDirectory always advertises into and queries from the default
scope, this list will become the default scope list for all eDirectory registrations and queries.
The DAAddresses option is a comma-delimited list of dotted decimal IP addresses of DAs that
should be preferred to all others. If this list of configured DAs does not support the scope of a
the cache).
adding new addresses to the cache).
cache).
cache).
DA cache).
known DA cache).
ones to the SA's known DA cache).
Manual (ENU) 21 December 2004
"User Agents" on page 116.).
Configuring OpenSLP for eDirectory
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