[Rstplib-users] RE: RSTP questions

[<al...@nb...>]

Albina,

{First, as Loren asked, could you avoid from posting pretty rstplib oriented
questions to 802.1 mailing list, please].

Now your questions:

On Monday, January 14, 2002 5:24 PM Albina Krigma-Lee asked:

Albina> 1. What does command 'ring' of 'mngr' do?

This command is an easy tool to organize a ring from virtual "bridges".
Its implementation has 2 states. On the first stages all ports on all
'bridges'
are being disconnected (I mean, 'mngr' calls command 'unlink'
in loop). On the second stage the second port on every  'bridge' (if it is
not last one) is connected to first port of next 'bridge'  and the second
port of the last 'bridge ' is connected to the first port of the first
'bridge'.
(sorry for so complicated definition).

Albina> 2. What do variables 'tev' and 'nev' in stp_in.c mean?

These variables I use for the debugging.
'tev' describes the type of event, that caused the current state machines
recalculation. All possible values of 'tev' you may find in the definition
of
enum RSTP_EVENT_T, defined in stp_In.c
The variable 'nev' is a circular counter of such event.
In RSTP simulator I don't show these variables, but in the real product
I print them as part of the prefix of  'stp_trace'. Example of the trace:

16:48:49.28:T:30:topoch  (_SNGL_-1.04): INACTIVE=>TCACTIVE
16:48:51.38:r:34:sttrans (_SNGL_-1.04): DISCARDING=>LEARNING
16:48:51.45:r:34:sttrans (_SNGL_-1.04): LEARNING=>FORWARDING
16:48:51.52:r:34:topoch  (_SNGL_-1.04): TCACTIVE=>DETECTED
16:48:51.58:r:34:DETECTED: tcWhile=4 on port 1.04
16:48:51.63:r:34:clearFDB (1.04, _SNGL_, other ports, 'DETECTED')
16:48:51.70:r:34:topoch  (_SNGL_-1.04): DETECTED=>TCACTIVE
16:48:53.01:r:36:topoch  (_SNGL_-1.04): TCACTIVE=>NOTIFIED_TC
16:48:53.07:r:36:clearFDB (1.04, _SNGL_, other ports, 'NOTIFIED_TC')
16:48:53.15:r:36:topoch  (_SNGL_-1.04): NOTIFIED_TC=>TCACTIVE
16:48:53.26:T:37:tcWhile=2 =>tx TOPOLOGY_CHANGE_BIT to port 1.04

Albina> 3. What does 802.1y mean?

It is a maintenance of IEEE 802.1w. Its full name is:"DRAFT IEEE Standard
for Local and Metropolitan Area Networks—Media
Access Control (MAC) Bridges—Amendment 3: Technical and
Editorial Corrections". This standard documents technical and editorial
corrections to IEEE Std 802.1D, 1998Edition, as modified
by IEEE Std 802.1t-2001 (Amendment 1) and
IEEE Std 802.1w-2001 (Amendment 2).

Albina> 4. Why the command set of 'bridge' does not contain
Albina> an option to change 'dot1dStpPathCostDefault' ?

You are right, the RSTP-MIB draft contains it. I have two justifications:
a) this MIB is a draft and has not been accepted as an official standard
b) IEEE Std. 802.1w doesn't not contain this object in 14.8.
Anyway, I'm going to implement it, but in the future.

Albina> 5. Why the format of reply on command "show port"
Albina> is different from format of reply on command
Albina> "show port 1".

OK, when you ask state of one port, the reply contains a detail information
of this port. When you don't define a port number, the reply contains
a brief information about all ports of the 'bridge'.

Albina> 6. What are "RSTP BPDU rx", "CONFIG BPDU rx" and
Albina> "TCN BPDU rx" ?

These are counters of all types of BPDUs, received on the port

Albina> 7. How many 'bridges' may RSTPlib simulate?

The 'mngr' contains a list of 'bridges' and doesn't have a limitation.
As far as I see, the may be only regular system limitations of memory
and number of opened sockets.
From other side, I suppose, that every 'bridge' will be opened in separate
shell; how mane shells can you open and watch ?

Best regards, Alex