Conference azur::mcc

The DECnet and IP autoconfiguration tools do not currently show position
relative to bridges.

However, the autoconfiguration portion of the ELM (Extended LAN Management)
package will provide additional information.  Perhaps more familiar with
that package could provide some details.

-- Erik

Peter,

The ELM kit has a spanning tree map FM.  Currently, this supports only RBMS
bridges.  It supports both LANbridge 100 and IEEE 802.1d spanning tree modes.
It doesn't currently support end station mapping.  That's something we are
working on for the next release.

Bob

One point to remember when using the address information contained in a bridge's
forwarding database is that it is aged out after short time if the station using
that address has not transmitted within the timeout period.

Put simply, the default time for ageing addresses from the forwarding database is
2 minutes. Therefore, if a station does not transmit for 2 minutes, its address
will be removed from the forwarding database. Thus any tool using this for 
positioning stations onto a particular LAN within the extended LAN must allow
for some station addresses not being held in the forwarding database of any
bridge.

This may sound insignificant, but consider the following. If any Digital
ethernet interface is powered up, but is not running any comms software, it will,
by default, send out a SYSID multicast message every 10 minutes (+- 2 minutes). 
This will be seen by the bridges on the network and entered in their forwarding 
databases. However, as it will be aged out after 2 minutes, that device will
only be capable of being seen for 2 out of every 10 minutes, or 20% of the time.

I would suggest, therefore, that any autoconfig tool that uses the address
information in the bridge forwarding databases examines them often enough to
catch those stations whose addresses get aged out under the above circumstances.

Paul.

	This is taken from the HP OpenView Node Manager flyer , it gives
	na idea of what we need to provide with DECmcc , at least what our
	customer are looking at (as provided by our major competitor ...):
	(Note that this work with HP equipement only).

	"The network Mgt. has a clear view of the Network'physical
        configuration to aid in both troubleshooting and inventory.
        Network Node Mgr automatically discovers HP' IP-addressable 10-10
        Bridges, Remote Bridges, Etherwist Hubs and Fiber Hubs. When these
        devices are discovered , Network Node Mgr automatically lays them out
        properly on the mao. In the case of bridges, it automatically
        detects which nodes are on which segment of the bridge. In the case of
        the EtherTwist anbd the FiberHub, it detects which ports have nodes
        connected , and lays out the map correctly"

	Regards ,
	MaRc
                      

    Re: .3 & .4  :
    
    If the bridge no longer has an address in its forwarding database, then
    you won't be able to find out where it is on the network, no matter
    which vendor's network manager is used.
    
    If you have registered the node previously, then simply issuing the
    equivalent of a "ping" to that node from the network management station
    will result in the address being "planted" in the forwarding database.
    
    That assumes the node is up and running.  If so, you will be able to
    obtain an accurate topological picture via the bridge forwarding
    databases.
    
    This is exactly what I do to find a node's location via my node search
    utility which searches the forwarding databases of all bridges.
    
    -Dan