| Title: | DEChub/HUBwatch/PROBEwatch CONFERENCE |
| Notice: | Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7 |
| Moderator: | NETCAD::COLELLA DT |
| Created: | Wed Nov 13 1991 |
| Last Modified: | Fri Jun 06 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 4455 |
| Total number of notes: | 16761 |
How do we handle a stuck beacon condition on a 900 MS backplane
FDDI connection.
The configuration in question is multiple DEChub 900MS' each
populated with 4 FDDI 14 port concentrators, interconnected with
two rings on the backplane, then uplinked to a Gigaswitch/FDDI.
The core question is "Is a stuck beacon condition auto healed" ?
How ?
If not, does this mean on bad FDDI station/NIC card could bring
down the entire network? Is the Gigaswitch the only point
of isolation.
Other vendors use a third MAC to isolate this condition. This is
a show stopper if we do not have an answer to this issue..
Jim
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 3548.1 | NETCAD::DOODY | Michael Doody | Thu May 23 1996 16:08 | 20 | |
A stuck beacon will usually result in a PC trace happening. This
causes the concentrators to go offline and do diagnostics.
If the "quick PC trace" option is enabled on the concentrator, it does
a small subset of tests and is back up in a few (2-3) seconds, assuming
the tests pass. No auto-healing is done or required. A failing module
(presumably the stuck beacon) will not come online within the 3
seconds and auto-healing will heal the ring around it.
If the "quick PC trace" option is disabled (default), the
concentrators go through their full diagnostics and are offline for
nearly a minute. Auto-healing will heal the ring around those
concentrators. When and if they complete their testing, they will
be re-inserted into the ring.
In the absence of auto-healing, I think the result of the PC trace
will be to wrap the ring around the offending module. You should
check with the FDDI gurus though.
-Mike
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| 3548.2 | trace or defer | NETCAD::CURRIER | Fri May 24 1996 12:47 | 7 | |
According to ANSI standard, a node must defer to another node that is
stuck beaconing. A node that is stuck beaconing must trace. That is
what 900 FDDI modules do.
-sheila
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| 3548.3 | follow on questions | ODIF11::LICATA | Thu May 30 1996 10:03 | 11 | |
Thanks for the replies.
Please excuse my ignorance of the FDDI spec.
Can a NIC card/port beacon or only a module ?
If the quick trace function is not the default
can the trace function enabled via Hubwatch or MCM ?
Jim
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| 3548.4 | NETCAD::DOODY | Michael Doody | Thu May 30 1996 11:17 | 7 | |
The quick PC trace option is disabled by default to be consistent with
the behavior of concentrators before the feature was added.
It can be enabled only through the conentrator's setup port, not via
NMS or ClearVISN.
-Mike
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