faq.txt

agentpp.com的免费的SNMP AGENT开发包. 本开发包来自 http://www.agentpp.com/ AGENT++ 版本v3.5.14 (包含VC7工程文件) AGENT++ W

AGENT++/AgentGen FAQ
====================


Q: I have downloaded SNMP++/AGENT++ from http://www.fock.de/agent++
   but I have problems to unzip/untar it.

A: Some browser do not recognize the extension "tar.gz". In order
   properly unzip the downloaded files you have to manually rename
   them to <filename>.tar.gz

--
Q: I have successfully compiled an AGENT++ example and run it. 
   But when sending a request to the agent, the request always
   times out.

A: The example agents listen on port 4700 by default, whereas
   the standard SNMP port is 161. Please specify port 4700
   when sending request to the (unmodified) example agents.
  
--
Q: Do you have any example code showing how to send a trap?

A: Since AGENT++v3.5.10 notifications (and informs) should be
   sent via Mib::notify, which supports notification sending 
   via the NotificationOriginator class by default. When using
   the AgentX++ subagent or Win32 subagent APIs, this method will
   send notifications with the correspondig subagent protocol 
   instead of using the NotificationOrigintor.

   You can send a trap in AGENT++v3.2 or later for example by:

	Vbx* vbs = 0;
	coldStartOid coldOid;
	Mib::notify(vbs, 0, coldOid, "", "");

   Please see the v3 online docs for more information on the
   NotificationOriginator class. The trap type (inform-request, trap,
   or notification) and the destinations are set via the 
   SNMP-NOTIFICATION-MIB and the SNMP-TARGET-MIB.

--
Q: I have build an agent with AGENT++/AgentGen for a MIB containing 
   SNMP tables. When I want to get a value from a table the agent
   returns "Not Available". The problem occurs only when accessing 
   tables.

A: Tables created via AgentGen are empty by default. You have to add 
   rows to a table in order to be able to access any instances
   within that table. 

--
Q: How can I add rows to a table.

A: First you have to create a valid index for the row:
   
   For a table with an INDEX clause like "INDEX { ifIndex, portNo }"
   this would be an index oid with two sub-identifiers for example

   "36.4000"

   In AGENT++v3.3 or later you can check an index for validity by
   calling MibTable::is_index_valid(const Oidx&).

   You then add a new row by

   Oidx ind("36.4000");
   if (!is_index_valid(ind)) printf("ERROR\n");
   MibTableRow* r = myIfEntry::instance->add_row(ind);

   You may then set the values of the new row by:

   rTntIfEntry::instance->set_row(r,4000,25);

--
Q: I would like to implement a read-only table or static 
   table, respectively. How can I realize it best?

A: Use the MibStaticTable and MibStaticEntry classes from
   mib_complex_entry.h. See the static_table example for
   details. 

--
Q: I would like to update the cached values in my table
   whenever a request for that table comes in. How can this 
   be done?

A: You should override the MibTable::update(Request*) method 
   in order to update your table. It is called whenever a 
   potential request for that table is processed. 

--
Q: How do I build the snmp++ and agent++ libraries using
   MS Visual C++ 6.0?

A: 1) Ensure that the include paths for snmp++ and agent++ 
      is searched _before_ the standard VC include paths.
      This because a wrong version of mib.h (and perhaps
      more files) get included.

   2) Compile using the Debug Multithread or just Multithread
      swithces on! Remember to define the flags 
      SNMP_PP_NATIVE_EXPORTS and AGENT_PP_NATIVE_EXPORTS.

   3) Start compiling as a lib, _not_ as dll.

   4) When having compiled the libs successfully, try
      compiling one of the test-agents. There are several
      things here you got to remember on setting up the 
      project:

      - Use same Multithread flag as for the libraries.
      - Turn of incremental link.
      - Ignore library: libcd.lig
      - Input snmp++, rsaeuro, agent++ libraries, +
        wsock32.lib.
      - Define the SNMP_PP_NATIVE_EXPORTS and
        AGENT_PP_NATIVE_EXPORTS flags
--
Q: I have succesfully compiled and linked my agent with 
   VC++, but when it starts or when sending requests to 
   the agent it crashes. Why?

A: Please make sure that all your projects (i.e., SNMP++
   AGENT++, etc.) are build with the same settings. 
   Especially the /ML or /MT flag must be consistently.
   
--
Q: When I try to make AGENT++ I got an error from make:
   "Do not know how to make "../include/*.h"

A: Your make does not support pattern rules. Please
   use GNU make or any other make utility that supports
   pattern rules instead.

--
Q: There seems to be missing files (Modules.mk, 
   module_includes.h, modules_init.h) in the agentgen 
   subdirectories?

A: These files are not missing. They will be generated
   by AgenPro. See http://www.agentpp.com for more
   information on code generation for AGENT++/AgentX++.

--
Q: How can I disable persistent storage for one or more
   MIB objects of my agent?

A: You may overwrite the MibEntry::is_presistent method
   to return FALSE, or, even simpler, you could add the
   MibEntry instance in question directly to the Mib
   instance instead of adding it to a MibGroup (which
   is then added to the MIB instance and then controls
   the persistent storage).

--
Q: When running an AgenPro generated (simulation) agent
   for some MIB modules persitent storage support fails
   to save MIB module content to disk, why?

A: AgenPro generates a MibGroup for each MIB module by
   default. Each MibGroup has to have a unique OID as 
   key. This key is determined by AgenPro as the root
   OID of a MIB module. If there MIB modules overlap
   this can cause the above described problem. To solve
   it, assign unique key OIDs to the MibGroups or 
   combine overlapping MibGroups. 


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