Conference azur::mcc

3979.0. "MCC/VMS LAN autodiscovery with a LAN bridge" by MAN02::STRUTH (Thomas Struth CS Mannheim) Wed Oct 28 1992 10:16

LAN Autodiscovery with DECmcc/VMS and a LAN bridge


Due to a customer request ( who payed parts of it ) I wrote a
utility to provide a kind of LAN station autodiscovery with DECmcc/VMS.


The basic idea is very simple. Just let DECmcc poll do a periodic
"show bridge mybridge forw database dynamic entry *, to file ... .
from a batch job , to create text files containing all learned
addresses. The system now reads  these addresses and triggers an 
autodiscovery- event for each new address using the datacollector.



To realize this, several (detached running) processes and a installed, 
shared, common database for a fast, common data storage are being used:

- Database: 
The database keeps one record with approx. 15 items per station address,
the current version is compiled for 2000 nodes which is less than 300k.
Using a simple $install delete... in a shutdown procedure saves all
collected information to disk.


Processes:

- ADIS_SCAN: Reads addresses out of the MCC- output file,
stores this information in the common db . Maintains timestamps for
first time seen, last time seen, begin of last inactivity period.
( customer request ) The threshold for the inact. period can be modified
by a logical.

- ADIS_PURGE is a program to allow selective  purging of the database.
Define it as a foreign command, then start it with /H <return> for more
information. ( interctive use )


- ADIS_NOTIFY_MCC runs in background like ADIS_SCAN. It creates "discovery"-
events via datacollector (-API) to DECmcc if either a new address was found, 
or a node exceeded the allowed inactivity period. 
This process  maintains several counters per node in the db, for example a 
" presence counter " and a presence
percent value, which is of course not a value for ethernet utilization
but a useful index for the "presence" of a node. 100% means simply that
this node sended at least 1 frame per (5-min) interval.
I am currently thinking of storing these values for the last 30 days
per node.
The severity level of the notifications can be customized. 
(see ADIS_LOGICALS)

The routine also checks whether a station is registered in the namespace.
For Decnet AA-00-... addresses I try to resolve a softlink in the DNA_-
BACKTRANSLATION directory, for all other addresses I check the other
appropriate backtranslation directories . ( terminalserver, bridges,stations )
This is done via sys$dns calls. 

If a station is registered, no event will be generated.

Because ip nodes cannot be handeled in that way, the current workaround 
is to register them also as ethernet stations.


- ADIS_REPORT is a program that creates a simple listing file with all
addresses seen, timestamps, dns names and some counters.
( not yet finished:The routine also creates mcc script files to register 
all unknown stations )



Some more functionality might follow. The software is now running since 
6 weeks at a large customer site and working fine. We will probably sell it 
for another time in November.

If interested,  copy AutoDIScovery from MANDSP::[ADIS_PUBLIC]
(MANDSP :  49.458).

Usage/installation:
You simply need DECMCC/VMS/DNS with the datacollector AM, a lan bridge, then
register a datacollector with the same name you specify in adis_logicals,
customize the adis- dcl procedures and run adis$startup.com . 
After a short time notifications should start.



I appreciate any kind of feedback. 


 Thomas

sounds neat.

please also post in noted::mcc-tools

    
I posted it also in mcc-tools. We should discuss it there. 
In .0  I made a mistake regarding the location of the kit:

please use    MANDSP::ADIS$PUBLIC  .

Thomas

MCC Lan Autodiscovery Update : 


- bridge name  + outbound port values are stored also now, 
  this means that polling of multiple bridges is possible.
- supports up to 2500 stations now
- new event when a "lost station" is re- discovered 
- new event when a station changes its location, this means that 
  an event is generated if the station is seen at another bridge or
  another port of the same bridge, or if a station with the same address as 
  an existing station is discovered on another lan segment.
- minor changes of report- format , more will follow soon. 



It can be copied from mandsp::adis$public:adis_v11.bck. It contains a new 
database ,which is not compatible to v1.0 . I recommend to delete all ad*.exe
files and at least mcc_read_bridge.com and to replace them with the updated 
version. 



Thomas 

Good day,

I'm using Thomas' ADIS tool (thanks Thomas!) but am having a problem with
MCC (V1.3 with ELM V1.3 installed).

When ADIS does a:

MCC> Show Bridge xxx Forwarding Database Dynamic Entry * with dispos=learned

the above command takes 20-25 minutes to complete! I'm on an idle 8550, 80 MB,
VMS V5.5-2, querying a LB200 V1.1.

Is there anything I can do to speed things up? 

Thanks,

Ed

    This is the kind of problem SNMP V2 "GET_BULK" will help solve...
    
    bill