| The Station Entity can be used for *quickly* checking connectivity at the
datalink level (check typically uses less system resources than other
methods).
For instance, there are classes of problems where protocols go belly-up,
but where the port device accessibility can tell you what type
of problem you're dealing with (e.g. DECnet or TCP/IP says it's not there,
but the port device is still accessible: must be a software problem).
Also, having a Station entity (icon) allows you to place entities on your map
that you cannot currently "manage" (verify connectivity to ethernet based entity
that doesn't have MCC support for its higher level protocols). In fact, the
entity may not implement any "higher level" protocol.
For Digital (and some other) hardware, you can also get information dealing
with the TYPE of Station you're dealing with; nice for those cases where
systems are getting added to your Ethernet before you're "told" about them).
Note that MOP is actually supported by more than just Digital at this point.
Some even support MOP datalink level counters.
Digital's Ethernet devices send SYSID messages every 8-12 minutes. This
fact will be used when the Ethernet AM implements Events (e.g. "New
Station Discovered").
That's all I have time to say (see the docs for more information).
Sorry about the multiple icon problem. It's has been known about for a LONG
time internally, but hasn't had a really high priority...
Chris
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| Gee, it sounds to me that you would want to have some (perhaps user
settable) "Default" protocol that DECmcc would use when accessing an
entity but provide for the user to choose other protocols if needed.
That way you don't need to have an Icon for each protocol, only one for
the entity.
s/rob
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| The right answer is going to come with testing it in the market. Right
now, few products support multiple protocols, but MSU, OPENview, and
Cabletron - all present one icon and support the various protocols
from within. MSU allows the operator to select the 'default' protocol
that is used for color on the map. HP will show a system a unique
color if SNMP is down, but reachable thru another protocol. This is
where the ethernet am is useful. What is also useful is the ability to
rank the protocols that should be tried during fault diagnosis of a
system. Ie, try DECnet first, then SNMP, then ICMP, then 802 loopback.
Since the MSU and Director products should come together at some point
soon, this might be a good place to make things look similar.
However - the feature of a box per protocol should not be totally
trashed - logical networks will still require using icons not tied
to the 'box' global class. For example, a map of message routers will use
message router icons - and not have to be tied to be within the system
that it's running in.
bill
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