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+SNMP data constraints verification error
+----------------------------------------
+
+Q. Will PySNMP Manager verify the values it sends to and receives from 
+   a distant Agent against local MIB constraints?
+
+A. Yes, it can do that. The Manager will verify the values you pass to SET
+   request against a MIB if:
+
+   The values are not already PyASN1 objects but some basic Python types 
+   (like integer or string). You tell PySNMP engine to load appropriate 
+   MIB where it could lookup the constraints (via the use of MibVariable)
+   So, the following code fragment makes PySNMP engine loading SNMPv2-MIB
+   and verifying that the 'new system name' value satisfies sysName 
+   constraints (if any).
+
+.. code-block:: python
+
+    errorIndication, errorStatus, errorIndex, varBinds = cmdGen.setCmd(
+        cmdgen.CommunityData('public'),
+        cmdgen.UdpTransportTarget(('localhost', 161)),
+        ( cmdgen.MibVariable('SNMPv2-MIB', 'sysName', 0), 'new system name' )
+    )
+
+   To verify the response values, you should pass at least lookupValues flag 
+   to CommandGenerator *cmd() method you use. In the following example 
+   PySNMP will make sure that Agent-supplied value for SNMPv2-MIB::sysName 
+   Managed Object satisfies MIB constraints (if any).
+
+.. code-block:: python
+
+    errorIndication, errorStatus, errorIndex, varBinds = cmdGen.getCmd(
+        cmdgen.CommunityData('public'),
+        cmdgen.UdpTransportTarget(('localhost', 161)),
+        cmdgen.MibVariable('SNMPv2-MIB', 'sysName', 0),
+        lookupValues=True
+    )
+
+   In case of constraint violation, a PySNMP exception will be raised.