Allied Telesyn International Corp TurboStack AT-S6 User's Guide download pdf (Page 61)

AT-S10 Management Software User’s Guide

If you removed the failed master, role determination causes the entire

department concentrator to reconﬁgure itself with new master and

backup. A new module then becomes the backup to the new master (the

previous backup).

A failure of the backup cannot be corrected without removing the module

itself; i.e., no other module can act as a backup for the backup.

Configuration Data

The master records all management agent conﬁguration information in

nonvolatile memory. This includes:

❑ The preferred human language for display

❑ Terminal characteristics

❑ Port configurations (enabled/disabled, etc.)

❑ User-specified port, module and hub names

❑ MAC address table

The master also copies this information into the non-volatile memory of

each installed hub module. These copies are maintained in order to

sustain department concentrator reconﬁgurations. The management

agent remembers conﬁguration data in spite of power failures, module

failures, and module swapouts, even of the master itself.

When a backup takes over on behalf of a failed or removed master, it

already has a current copy of all necessary conﬁguration data. When you

swap out the master and install a new module, the new master will

receive correct and current conﬁguration data from the Backup (previous

master). This avoids the need to re-specify all of the conﬁguration

preferences. The process all happens transparently within seconds of the

swapout.

Precedence If you install a module from another network as the new master in a

concentrator, it may contain some old conﬁguration data from its previous

existence (it may have been installed in a different department

concentrator chassis at one time). When it begins operating in its new

location, the master does not know if its own conﬁguration data is correct

or not. The backup has some data, but its data may or may not be the

correct data for this particular chassis.

This issue between the two modules is resolved by an examination of their

respective elapsed time counters (each maintains a time-since-last-

reboot). If the backup has been up and running longer than the master,

the conclusion is that the master must have just been inserted and

contains “old” data. The data from the backup is more current and is

therefore copied into the new master. But if both modules have just booted

(presumably because you just reset the entire department concentrator)

then the clock alone cannot determine whose data is correct (both clocks

would read the same). In this case, the master attempts to resolve this

through a process called voting.

1 2 ... 56 57 58 59 60 61 62 63 64 65 66 ... 77 78

Comments to this Manuals

No comments

Allied Telesyn International Corp TurboStack AT-S6 User's Guide Page 61

Comments to this Manuals

Related products and manuals for Network switches Allied Telesyn International Corp TurboStack AT-S6