Usm User Limit

In*snmp*user based security model what is the maximum number of usm*users*limit ?


__________________________________________________ ________
Sent from Yahoo! Mail.
A Smarter Email http://uk.docs.yahoo.com/nowyoucan.html

-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2008.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
_______________________________________________
Net-snmp-coders mailing list
Net-snmp-coders@lists.sourceforge.net
https://lists.sourceforge.net/lists/...et-snmp-coders

2008/6/2 Amit Kumar <nc_usa27566@yahoo.com>:
> In snmp user based security model what is the maximum number of usm users limit ?

Well, the usmUserName object is limited to 32 printable characters.
If you restrict yourself to alphanuneric lower case names, that
would give you 36 possibilities for each character.
Some quick calculations indicate there are something of the
order of 6.5 * 10^49 possible such usernames.

I suspect you might be more restricted by the memory available in
your target box. You'll probably get around 3 usmUser structures
per Kb memory, so 3,000 users will occupy around 1Mb. You can
scale things up to larger configurations yourself.


I can pretty much guarantee that the agent has never been tested
with such large configurations, so you might find that a large number
of USM users might impact performance. (Finding a given user
from within a simple linked list is easy but not particularly efficient!)

Dave

-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2008.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
_______________________________________________
Net-snmp-coders mailing list
Net-snmp-coders@lists.sourceforge.net
https://lists.sourceforge.net/lists/...et-snmp-coders

>>>>> On Mon, 2 Jun 2008 09:25:54 +0100, "Dave Shield" <D.T.Shield@liverpool.ac.uk> said:

DS> I can pretty much guarantee that the agent has never been tested
DS> with such large configurations, so you might find that a large number
DS> of USM users might impact performance. (Finding a given user
DS> from within a simple linked list is easy but not particularly efficient!)

The most important aspect is that last one: the internal storage of the
user list is not efficient at the moment so at some point adding more
users will impact the speed at which the stack can process packets and
the USM implementation will become the most limiting factor.

It's one of those things that was done the way it is and was intended to
be rewritten at a later date but never was.
--
Wes Hardaker
Sparta, Inc.

-------------------------------------------------------------------------
Check out the new SourceForge.net Marketplace.
It's the best place to buy or sell services for
just about anything Open Source.
http://sourceforge.net/services/buy/index.php
_______________________________________________
Net-snmp-coders mailing list
Net-snmp-coders@lists.sourceforge.net
https://lists.sourceforge.net/lists/...et-snmp-coders

Wes Hardaker wrote:
> It's one of those things that was done the way it is and was intended to
> be rewritten at a later date but never was.

Contributions *highly* appreciated, of course!


+Thomas

--
Thomas Anders (thomas.anders at blue-cable.de)

-------------------------------------------------------------------------
Check out the new SourceForge.net Marketplace.
It's the best place to buy or sell services for
just about anything Open Source.
http://sourceforge.net/services/buy/index.php
_______________________________________________
Net-snmp-coders mailing list
Net-snmp-coders@lists.sourceforge.net
https://lists.sourceforge.net/lists/...et-snmp-coders