ACE/ASNMP/asnmp-overview.html

   1 <html>
   2 <!--  -->
   3 <! by Michael R. MacFaden mrm@cisco.com >
   4 <title>ASNMP Overview</title>
   5
   6 <h1>ASNMP Overview</h1>
   7
   8 <p>The Another SNMP class library is an Object Oriented programming
   9 toolkit for using IETF standard network management protocols in the
  10 Internet.  The SNMP protocol is perhaps the most ubiquitous management
  11 protocol running on most very device or application deployed in the
  12 modern network today.
  13
  14 <p>ASNMP is targeted to programmers that want to write command and
  15 control (C&C) applications. C&C Applications communicate with
  16 a variety of objects:
  17 <sl>
  18 <li>network devices such as ATM switches, Internet routers,
  19 LAN bridges and LAN printers
  20 <li>Routing protocols such as OSPF
  21 <li>database servers such as ORACLE or Informix.
  22
  23 <p>ASNMP Version 1 implements a blocking SNMP Version 1 with some
  24 Version 2c additions (Counter32, Counter64 SMI values).  See
  25 SNMP Version 1 as defined in the IETF Request for Comments (RFC)
  26 <sl>
  27 <li>1155
  28 <li>1157
  29 <li>1213
  30 <li>1215
  31 <sl>
  32 <p>Also see the RFC 1902 spec for new SMI datatypes such as Counter64.
  33
  34 <p>ASNMP is built using the CMU SNMP and HP SNMP++ as the base
  35 classes then modified for use in the ACE framework. About 10% of the API
  36 changed during code rework. See ASNMP/asnmp/ChangeLog for details.
  37
  38 <p>ASNMP can be used for either manager applications or agent applications.
  39 The <i>Snmp</i> class contains the interface for manager applications. The
  40 <i>sagent</i> class contains the interface for agent applications. A
  41 trivial agent that implements the mib II system group per rfc1213 is
  42 in the agents/ directory.
  43
  44 <h2>Class Hierarchy</h2>
  45
  46 <pre>
  47 UdpTarget - Defines a collection of attributes needed to define a
  48              communications session with an SNMP agent
  49             This includes  network address, response timeout, etc.
  50
  51 Snmp - A logical session between NM app and agent. Provides the
  52        commands get, get_next, trap. Manages transactions between app and
  53        server.
  54
  55 Pdu  - A container object that represents an SNMP Protocol Data Unit.
  56        A Pdu contains a command (get,getnext,trap) Varbind List list,
  57        a community string.
  58
  59 Vb   - Aka Varbind or Variable Binding.  A pdu can have zero,
  60        one or more of these. A Vb consists of an Oid to identify
  61        the variable and a value corresponding to  one of the SMI values.
  62        The oid/value binding is defined in a MIB file (RFC 1155)
  63        Agents hava a MIB file that defines what each variable means.
  64        Most agents implement MIB II as defined in RFC 1156.
  65
  66 <p>The Structure of Management Information (SMI) datatypes
  67 and related types are:
  68 <ul>
  69 <li>Address->IpAddress->UdpAddress as well as MAC, IPX, IPXSOCK, Netbios
  70 <li>Unsigned Integer
  71 <li>Gauge32
  72 <li>Integer32
  73 <li>Counter32
  74 <li>Counter64
  75 <li>TimeTicks
  76 <li>OctetStr
  77 <li>Oid
  78 </ul>
  79
  80 <hr>
  81
  82 <h2>Sample program</h2>
  83 <p>A sample Object to get obtain an Agent's Systems' Description
  84 given an network address and a community string.
  85
  86 class system_id {
  87    public:
  88    system_id(UdpAddress addr, OctetStr read_community_string)
  89      {
  90       UdpTarget tgt;
  91       Snmp snmp;
  92       Pdu pdu;
  93       Oid oid("1.3.6.1.2.1.1.1.0");
  94       Vb vb(oid);
  95       tgt.set_address(addr);
  96       tgt.set_read_community(read_community_string);
  97       pdu += vb;
  98
  99       if (snmp.get(pdu, tgt) == 0) {
 100          pdu.get_vb(vb, 0);
 101          vb.get_value(desc_);
 102       }
 103       else
 104        desc_ = "<error - no value set>"
 105      }
 106
 107    int get_description(OctetStr& description) {
 108           description =  desc_;
 109           return 0;
 110    }
 111
 112 private:
 113     OctetStr desc_;
 114 };
 115
 116 <h1>Future Directions</h1>
 117 <p>Here are some areas for further work
 118 <sl>
 119 <li>Add OO mib parser and mib code generator
 120 <li>Collapse the CMU/HP code into one set of classes.
 121 <li>Add full V2c support.
 122 <li>Size/Speed improvements
 123 </sl>
 124
 125 <h1>References</h1>
 126 <ul>
 127 <li><a href="http://www.ece.ucdavis.edu/ucd-snmp/">UCD SNMP</a>
 128 <li><a href="news://comp.protocols.snmp">comp.protocols.snmp</a>
 129 <li><a href="http://snmp.cs.utwente.nl">University of Twente</a>
 130 <li><a href="http://www.cis.ohio-state.edu/hypertext/faq/bngusenet/comp/protocols/snmp/top.html">SNMP FAQ</a>
 131 <li><a href="http://www.adventnet.com/">Java based SNMP tools from Ardent</a>
 132 <li><a href="http://misa.zurich.ibm.com/Webbin/">IBM SNMP/CMIP research</a>
 133 </ul>
 134 </html>