| 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 |
This note is to alert the field to a problem we have found with the
DECserver 90L+ firmware. This problem will be seen in:
DEChub 90 (_not_ in the DEChub 900)
with:
DECbridge 90 (any model or rev)
DECserver 90L+ with firmware version 'BL5.2'
The symptom you will see is that the bridge claims not to be the
manager of the hub. If you are managing it using HUBwatch (any rev,
any platform) and/or a DECagent 90 then you will see an error to the
effect that the it was unable to obtain management information for the
community. If you connect to the remote console of the bridge (MOP)
and do a 'SHOW REPEATER' command it will deny that it is the manager
of the hub.
The Firmware rev for the 90L+ with the problem is:
DECserver 90L+ V2.0 BL5.2
We are working on getting a firmware release out ASAP with the fix; I
will post a reply to this note when we have one.
In the mean time we have no workaround to permit management of the hub
other than removing the DECserver 90L+ and leaving it out...
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 530.1 | The details | QUIVER::SLAWRENCE | Tue Nov 30 1993 17:17 | 23 | |
This followup to explain what the problem really is, for the curious. When the bridge polls each slot on the serial management bus for the module identity (the "Who Are You Poll"), the terminal server responds with an extra character at the end of its response. The character is a line feed, which helps in debugging, but it should have been added to the front of the message (where it would be ignored) rather than the end. The effect is that the bridge sees an unsolicited character on the management bus and decides that there is another bus master out there, so it stops being the master (the ulitimate in simple arbitration schemes). This makes the hub unmanagable. The reason that the problem will not be seen in a DEChub 900 is that the management channel is not a bus; it is a star, with the Management Agent Module (MAM) at the center. When it does not have an IP address of its own, the MAM forwards management messages on the star on behalf of any DEChub 90 bus master (in this case, the bridge) to make it look like the 90 management bus. However, the forwarding is 'smart', and strips the extra character (mostly luck, really, we _could_ have done it the other way). | |||||