[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference netcad::hub_mgnt

Title:DEChub/HUBwatch/PROBEwatch CONFERENCE
Notice:Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7
Moderator:NETCAD::COLELLADT
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

789.0. "disabling the management station port" by CERN::JRS (John SHADE - 'Attila the Nun') Thu Mar 03 1994 14:38

   I have a DEChub900 with a DECrepeater900 module installed. The network (and
   hence the management station (a PC running T2.8)) is connected to port 1.
   Using HUBwatch, I disabled port 1 and, lo and behold, the agent stopped
   responding.

   Does the HUBwatch software know which MAC address it's receiving the SNMP
   commands from? If so, I would have thought it a good idea that you pop up a
   dialog box asking "Do you really want to shoot yourself in the foot?".

   Comments?

   -John
T.RTitleUserPersonal
Name		DateLines
789.1It hurts - don't do thatQUIVER::SLAWRENCEThu Mar 03 1994 15:0719
    
    We just provide you the fully loaded high caliber automatic weapon....
    :-) 
    
    It turns out that when you consider all the different possibilities for
    how your management messages might get to the agent, and all the ways
    you can interrupt that path, there is little that HUBwatch can do to
    protect you from yourself.  It does some of those (if you remove a
    repeater from the network in the LAN interconnect screen you get an
    "are you sure" kind of query).  But to prevent the error you made, it
    would not only have to know that the management messages were coming
    from that repeater, but that they were coming through that port - which
    would mean searching the address table for the entire repeater (it is
    not organized to search for a single port) and check for its own MAC
    address (or the address of the router through which its packets reach
    the hub - and finding that is another whole rathole)....
    
    You probably get the picture - HUBwatch is quite slow enough.
789.2Are you sure? <Yes> <No> Really sure? <Yes> <No> Wicked awful sure? <Yes> <No>SLINK::HOODI'd rather be surfingThu Mar 03 1994 15:5917
.1:
>    You probably get the picture - HUBwatch is quite slow enough.

Aww, gee,  "Larry Scott"!  We have new releases of HUBwatch every few
days.  I think that's pretty fast...

Scott is right.  The more digging through MIBs we have to do, and the more
network traffic we generate, the, uh, less performance-oriented we become.  
On the new 900MX bridge, it's simple to see where the SNMP comes from.  Where 
we can detect such things without acrobatics, we provide the ever-annoying 
"Are you sure" boxes.

But on repeaters, eyouch!  Or figuring out whether to disable the terminal
server port which provides OOB...  Giant morass from the HUBwatch side.

Tom Hood
HUBwatch