DOCUMENT:Q228900  03-MAR-2001  [sms]
TITLE   :SMS: How SMS 2.0 Network Discovery Sees Clients With Static IPs
PRODUCT :Microsoft Systems Management Server
PROD/VER::2.0
OPER/SYS:
KEYWORDS:kbnetwork kbsetup kbClient kbConfig kbServer kbSNMP kbsms200 kbDiscovery kbInventory

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The information in this article applies to:

 - Microsoft Systems Management Server version 2.0 
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SUMMARY
=======

Systems Management Server 2.0 Network Discovery may not report discovery data
for computers that have static IP addresses. Viewing the Netdisc.log (logging
must be enabled via Systems Management Server Service Manager) reveals that the
computer is found and it's IP address is identified, but a Data Discovery Record
(DDR) is not written. A DDR is not written unless the subnet mask of the
computer can be positively determined.

Systems Management Server 2.0 Network Discovery can determine the subnet mask of
the client from the following sources:

 - A Microsoft DHCP Server. Network Discovery retrieves the active leases and
   defined subnet lists that have been configured on the DHCP server. Note that
   the Systems Management Server Service account requires at least Domain User
   access to the DHCP server. Also, if the Site Server is installed on a Windows
   NT Server with a static IP address, make sure that the IP address of the DHCP
   server has been entered in the DHCP tab of Network Discovery Properties. Site
   servers with a static IP address do not find the local DHCP server if the
   "Use local DHCP servers" box is checked but no DHCP servers have been
   entered.

 - An SNMP agent. Make sure that the community name is specified correctly in
   the SNMP tab of Network Discovery Properties. Note that the site server's
   default gateway is automatically included in the list of SNMP devices Network
   Discovery contacts to gather information. Systems Management Server attempts
   to gather information about other SNMP devices on the network, but it may be
   necessary to add the IP address of SNMP devices (such as routers) to the SNMP
   Devices tab of Network Discovery Properties.

 - The router ARP cache entry. To discover machines with static addresses, it is
   necessary to have an SNMP agent installed on the client, or the client needs
   to be in the local router's ARP cache. In general, entries only remain in the
   ARP cache anywhere from 60 seconds to about 10 minutes, depending on the
   router software and the TimeToLive value. Check the router configuration to
   determine its cache.

There are utilities available to view the ARP cache of a router such as the ARP
command line utility. The following command should return the current contents
of the router cache:

"ARP -a routerIPaddress" (without the quotation marks)

Since entries do age out of the ARP cache, it may be necessary to schedule
network discovery to run multiple times to find all machines. Also, if a machine
is especially "quiet" it may not appear in the ARP cache of the local router.
Any communication across a router, such as a ping to a remote network, will add
the machine to the ARP cache of the router.

NOTE: When topology, topology and client, and topology, client and client
operating system network discovery is enabled, Microsoft Windows 95, Windows 98,
or Windows Millennium Edition clients only report discovery datas if they have
File and Print sharing enabled.

Computers that have statically assigned addresses can be added to a DHCPs
RESERVED list and be successfully discovered with Network Discovery. For
additional information, click the article number below to view the article in
the Microsoft Knowledge Base:

   Q236036 SMS: NetDisc Fails to Discover Static IP Addresses Reserved

Additional query words: prodsms

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Keywords          : kbnetwork kbsetup kbClient kbConfig kbServer kbSNMP kbsms200 kbDiscovery kbInventory 
Technology        : kbSMSSearch kbSMS200
Version           : :2.0
Issue type        : kbinfo

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