User`s guide

The RingView Tools Dialog Box
Discovery Options
The User Interface RingView for FDDI
3-4 User’s Guide
Discovery Options
The Discovery Options panel at the top of the dialog box lets you start a
discovery session for the FDDI LAN at any time by clicking on the Discover
Ring button. An “Action successful” message box will be displayed to inform
you when the discovery session is completed. Click on “Close” to dismiss the
message box. The results of the discovery session will then be visible in the
FDDI LAN Topology view. Note that you can still run a discovery session
using the Discover Ring button regardless of the Background Discovery or
AutoDiscovery/Prevent settings described below.
If you wish to run discovery sessions at pre-determined intervals, the
Background Discovery toggle button must be set to “On.” Intervals are
defined in hours by entries you make in the Discovery Interval field. The
default value is 24 hours.
The other toggle button in this panel lets you preserve any customizations you
make to the FDDI LAN topology by preventing subsequent sessions of
AutoDiscovery from launching RingView. Set the Prevent button to “Yes” to
preserve your customizations. See the following note concerning the use of
RingView when DECnet protocol is present.
Display Settings
The Display Settings panel at the bottom of the dialog box lets you customize
the associated Topology view using the following three selector buttons.
NOTE
As noted in Chapter 2, there is a fundamental incompatability between the
ways in which RingView and DECnet treat MAC addresses. RingView’s basic
mapping methodology depends on the MAC address being used as a constant
and unique node identifier. However, the MAC address of a DECnet node may
change whenever the DECnet protocol is started or restarted. Thus RingView
may encounter both an orignal MAC address and a DECnet-assigned MAC
address for the same node. Also the same MAC address may be used for each
of a DECnet node’s interfaces.
To deal with the problem of a node’s address changing, RingView will
automatically default the Prevent AutoDiscovery setting to “Yes” whenever a
DECnet MAC address is detected. You can then run RingView on-demand at a
time when the network is known to be stable.
The problem of duplicate MAC addresses requires some user action. If the
FDDI LAN Topology view resulting from an initial AutoDiscovery session
contains wrong or duplicate DECnet MAC address models, you will need to
determine which one actually represents the device, then erase the others from
the view. The correct model will now be associated with the FDDI LAN
through SPECTRUM’s “Collects” relation, and a subsequent session of
RingView will be able to accurately map the ring topology.