Merge branch 'maint-r14' into bmk/snmp/snmp4216_integration/r15

Conflicts:
	lib/snmp/doc/src/notes.xml
	lib/snmp/doc/src/notes_history.xml

10 files changed, 664 insertions, 208 deletions

diff --git a/lib/snmp/src/agent/depend.mk b/lib/snmp/src/agent/depend.mk
index bc39e1fa35..078ef15821 100644
--- a/lib/snmp/src/agent/depend.mk
+++ b/lib/snmp/src/agent/depend.mk
@@ -52,6 +52,7 @@ $(EBIN)/snmpa_acm.$(EMULATOR): \
 
 $(EBIN)/snmpa_agent.$(EMULATOR): \
 	snmpa_agent.erl \
+	snmpa_internal.hrl \
 	../misc/snmp_debug.hrl \
 	../misc/snmp_verbosity.hrl \
 	../../include/snmp_types.hrl
@@ -136,6 +137,7 @@ $(EBIN)/snmpa_set_lib.$(EMULATOR): \
 
 $(EBIN)/snmpa_supervisor.$(EMULATOR): \
 	snmpa_supervisor.erl \
+	snmpa_internal.hrl \
 	../misc/snmp_debug.hrl \
 	../misc/snmp_verbosity.hrl
 
diff --git a/lib/snmp/src/agent/snmp_target_mib.erl b/lib/snmp/src/agent/snmp_target_mib.erl
index 60bd3e0912..a45db89c09 100644
--- a/lib/snmp/src/agent/snmp_target_mib.erl
+++ b/lib/snmp/src/agent/snmp_target_mib.erl
@@ -46,8 +46,14 @@
 %% Column not accessible via SNMP - needed when the agent sends informs
 -define(snmpTargetAddrEngineId, 10).
 %% Extra comlumns for the augmented table snmpTargetAddrExtTable
--define(snmpTargetAddrTMask, 11).
--define(snmpTargetAddrMMS, 12).
+-define(snmpTargetAddrTMask,    11).
+-define(snmpTargetAddrMMS,      12).
+
+-ifdef(snmp_extended_verbosity).
+-define(vt(F,A), ?vtrace(F, A)).
+-else.
+-define(vt(_F, _A), ok).
+-endif.
 
 
 %%-----------------------------------------------------------------
@@ -459,10 +465,16 @@ get_target_addrs() ->
 
 
 get_target_addrs(Key, {Tab, _} = TabDb, Acc) ->
+    ?vt("get_target_addrs -> entry with"
+	"~n   Key: ~p", [Key]),
     case table_next(Tab, Key) of
 	endOfTable -> 
+	    ?vt("get_target_addrs -> endOfTable when"
+		"~n   Acc: ~p", [Acc]),
 	    Acc;
 	NextKey ->
+	    ?vt("get_target_addrs -> next ok: "
+		"~n   NextKey: ~p", [NextKey]),
 	    case get_target_addr(TabDb, NextKey) of
 		{ok, Targ} ->
 		    get_target_addrs(NextKey, TabDb, [Targ| Acc]);
diff --git a/lib/snmp/src/agent/snmpa.erl b/lib/snmp/src/agent/snmpa.erl
index 50b169e4e7..c400aaddf7 100644
--- a/lib/snmp/src/agent/snmpa.erl
+++ b/lib/snmp/src/agent/snmpa.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2004-2011. All Rights Reserved.
+%% Copyright Ericsson AB 2004-2012. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -547,7 +547,7 @@ update_mibs_cache_age(Agent, Age) ->
 
 
 update_mibs_cache_gclimit(GcLimit) ->
-    update_mibs_cache_age(snmp_master_agent, GcLimit).
+    update_mibs_cache_gclimit(snmp_master_agent, GcLimit).
 
 update_mibs_cache_gclimit(Agent, GcLimit) ->
     snmpa_agent:update_mibs_cache_gclimit(Agent, GcLimit).
diff --git a/lib/snmp/src/agent/snmpa_agent.erl b/lib/snmp/src/agent/snmpa_agent.erl
index d3eeca2290..17cb9c9fe3 100644
--- a/lib/snmp/src/agent/snmpa_agent.erl
+++ b/lib/snmp/src/agent/snmpa_agent.erl
@@ -68,8 +68,11 @@
 %% Internal exports
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
 	 terminate/2, code_change/3, tr_var/2, tr_varbind/1,
-	 handle_pdu/7, worker/2, worker_loop/1, 
+	 handle_pdu/8, worker/2, worker_loop/1, 
 	 do_send_trap/7, do_send_trap/8]).
+%% <BACKWARD-COMPAT>
+-export([handle_pdu/7]).
+%% </BACKWARD-COMPAT>
 
 -include("snmpa_internal.hrl").
 
@@ -87,7 +90,6 @@
 
 -define(DISCO_TERMINATING_TRIGGER_USERNAME, "").
 
-
 -ifdef(snmp_debug).
 -define(GS_START_LINK3(Prio, Parent, Ref, Opts),
         gen_server:start_link(?MODULE, [Prio, Parent, Ref, Opts],
@@ -103,13 +105,49 @@
         gen_server:start_link({local, Name}, ?MODULE, 
 			      [Prio, Parent, Ref, Opts],[])).
 -endif.
- 
+
+%% Increment this whenever a change is made to the worker interface 
+-define(WORKER_INTERFACE_VERSION, 1).
+
+%% -- Utility macros for creating worker commands --
+-define(mk_pdu_wreq(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra),
+	#wrequest{cmd  = handle_pdu, 
+		  info = [{vsn,        Vsn}, 
+			  {pdu,        Pdu}, 
+			  {pdu_ms,     PduMS}, 
+			  {acm_data,   ACMData}, 
+			  {addr,       Address}, 
+			  {gb_max_vbs, GbMaxVBs}, 
+			  {extra,      Extra}]}).
+-define(mk_send_trap_wreq(TrapRec, NotifyName, ContextName, 
+			  Recv, Vbs, LocalEngineID, Extra),
+	#wrequest{cmd  = send_trap, 
+		  info = [{trap_rec,        TrapRec}, 
+			  {notify_name,     NotifyName}, 
+			  {context_name,    ContextName}, 
+			  {receiver,        Recv}, 
+			  {varbinds,        Vbs}, 
+			  {local_engine_id, LocalEngineID},
+			  {extra,           Extra}]}).
+-define(mk_terminate_wreq(), #wrequest{cmd = terminate, info = []}).
+-define(mk_verbosity_wreq(V), #wrequest{cmd  = verbosity, 
+					info = [{verbosity, V}]}).
+
 
 -record(notification_filter, {id, mod, data}).
 -record(disco, 
 	{from, rec, sender, target, engine_id, 
 	 sec_level, ctx, ivbs, stage, handler, extra}).
 
+%% This record is used when sending requests to the worker processes
+-record(wrequest, 
+	{
+	  version = ?WORKER_INTERFACE_VERSION, 
+	  cmd, 
+	  info
+	 }
+       ).
+
 
 %%-----------------------------------------------------------------
 %% The agent is multi-threaded, i.e. each request is handled
@@ -142,7 +180,8 @@
 		net_if_mod,   
 		backup,
 		disco,
-		mibs_cache_request}).
+		mibs_cache_request,
+		gb_max_vbs}).
 
 
 %%%-----------------------------------------------------------------
@@ -330,6 +369,8 @@ do_init(Prio, Parent, Ref, Options) ->
     MultiT  = get_multi_threaded(Options),
     Vsns    = get_versions(Options),
 
+    GbMaxVbs = get_gb_max_vbs(Options), 
+
     NS = start_note_store(Prio, Ref, Options),
     {Type, NetIfPid, NetIfMod} = 
 	start_net_if(Parent, Prio, Ref, Vsns, NS, Options),
@@ -348,7 +389,8 @@ do_init(Prio, Parent, Ref, Options) ->
 		ref            = Ref,
 		vsns           = Vsns,
 		note_store     = NS,
-		net_if_mod     = NetIfMod}}.
+		net_if_mod     = NetIfMod,
+		gb_max_vbs     = GbMaxVbs}}.
 
 
 start_note_store(Prio, Ref, Options) ->
@@ -410,7 +452,8 @@ start_net_if(Parent, _Prio, _Ref, _Vsns, _NoteStore, _Options)
 start_mib_server(Prio, Ref, Mibs, Options) ->
     ?vdebug("start_mib_server -> with Prio: ~p", [Prio]),
     MibStorage = get_mib_storage(Options),
-    MibsOpts = [{mib_storage, MibStorage}|get_option(mib_server, Options, [])],
+    MibsOpts   = [{mib_storage, MibStorage} | 
+		  get_option(mib_server, Options, [])],
 
     ?vtrace("start_mib_server -> "
 	    "~n   Mibs:     ~p"
@@ -751,7 +794,8 @@ handle_info({snmp_pdu, Vsn, Pdu, PduMS, ACMData, Address, Extra}, S) ->
     ?vdebug("handle_info(snmp_pdu) -> entry with"
 	    "~n   Vsn:     ~p"
 	    "~n   Pdu:     ~p"
-	    "~n   Address: ~p", [Vsn, Pdu, Address]),
+	    "~n   Address: ~p"
+	    "~n   Extra:   ~p", [Vsn, Pdu, Address, Extra]),
     
     NewS = handle_snmp_pdu(is_valid_pdu_type(Pdu#pdu.type),
 			   Vsn, Pdu, PduMS, ACMData, Address, Extra, S),
@@ -1076,7 +1120,7 @@ handle_call({subagent_get_next, MibView, Varbinds, PduData}, _From, S) ->
 	  "~n   PduData:  ~p", 
 	  [MibView,Varbinds,PduData]),
     put_pdu_data(PduData),
-    {reply, do_get_next(MibView, Varbinds), S};
+    {reply, do_get_next(MibView, Varbinds, infinity), S};
 handle_call({subagent_set, Arguments, PduData}, _From, S) ->
     ?vlog("[handle_call] subagent set:"
 	  "~n   Arguments: ~p"
@@ -1117,7 +1161,7 @@ handle_call({get_next, Vars, Context}, _From, S) ->
             ?vdebug("Varbinds: ~p",[Varbinds]),
             MibView = snmpa_acm:get_root_mib_view(),
             Reply =
-                case do_get_next(MibView, Varbinds) of
+                case do_get_next(MibView, Varbinds, infinity) of
                     {noError, 0, NewVarbinds} ->
                         Vbs = lists:keysort(#varbind.org_index, NewVarbinds),
 			[{Oid,Val} || #varbind{oid = Oid, value = Val} <- Vbs];
@@ -1313,15 +1357,15 @@ handle_call(Req, _From, S) ->
     Reply = {error, {unknown, Req}}, 
     {reply, Reply, S}.
     
-handle_cast({verbosity,Verbosity}, S) ->
-    ?vlog("verbosity: ~p -> ~p",[get(verbosity),Verbosity]),
+handle_cast({verbosity, Verbosity}, S) ->
+    ?vlog("verbosity: ~p -> ~p",[get(verbosity), Verbosity]),
     put(verbosity,snmp_verbosity:validate(Verbosity)),
     case S#state.worker of
-	Pid when is_pid(Pid) -> Pid ! {verbosity,Verbosity};
+	Pid when is_pid(Pid) -> Pid ! ?mk_verbosity_wreq(Verbosity);
 	_ -> ok
     end,
     case S#state.set_worker of
-	Pid2 when is_pid(Pid2) -> Pid2 ! {verbosity,Verbosity};
+	Pid2 when is_pid(Pid2) -> Pid2 ! ?mk_verbosity_wreq(Verbosity);
 	_ -> ok
     end,
     {noreply, S};
@@ -1408,13 +1452,80 @@ handle_mibs_cache_request(MibServer, Req) ->
 
 %% Downgrade
 %%
-%% code_change({down, _Vsn}, S, downgrade_to_pre_4_13) ->
-%%     {ok, S2};
+code_change({down, _Vsn}, S1, downgrade_to_pre_4_17_3) ->
+    #state{type               = Type, 
+	   parent             = Parent, 
+	   worker             = Worker, 
+	   worker_state       = WorkerState,
+	   set_worker         = SetWorker, 
+	   multi_threaded     = MT, 
+	   ref                = Ref, 
+	   vsns               = Vsns,
+	   nfilters           = NF,
+	   note_store         = NoteStore,
+	   mib_server         = MS, 
+	   net_if             = NetIf, 
+	   net_if_mod         = NetIfMod, 
+	   backup             = Backup,
+	   disco              = Disco,
+	   mibs_cache_request = MCR} = S1, 
+    S2 = {state, 
+	  type               = Type, 
+	  parent             = Parent, 
+	  worker             = Worker, 
+	  worker_state       = WorkerState,
+	  set_worker         = SetWorker, 
+	  multi_threaded     = MT, 
+	  ref                = Ref, 
+	  vsns               = Vsns,
+	  nfilters           = NF,
+	  note_store         = NoteStore,
+	  mib_server         = MS, 
+	  net_if             = NetIf, 
+	  net_if_mod         = NetIfMod, 
+	  backup             = Backup,
+	  disco              = Disco,
+	  mibs_cache_request = MCR}, 
+    {ok, S2};
 
 %% Upgrade
 %%
-%% code_change(_Vsn, S, upgrade_from_pre_4_13) ->
-%%     {ok, S2};
+code_change(_Vsn, S1, upgrade_from_pre_4_17_3) ->
+    {state, 
+     type               = Type, 
+     parent             = Parent, 
+     worker             = Worker, 
+     worker_state       = WorkerState,
+     set_worker         = SetWorker, 
+     multi_threaded     = MT, 
+     ref                = Ref, 
+     vsns               = Vsns,
+     nfilters           = NF,
+     note_store         = NoteStore,
+     mib_server         = MS, 
+     net_if             = NetIf, 
+     net_if_mod         = NetIfMod, 
+     backup             = Backup,
+     disco              = Disco,
+     mibs_cache_request = MCR} = S1,
+    S2 = #state{type               = Type, 
+		parent             = Parent, 
+		worker             = Worker, 
+		worker_state       = WorkerState,
+		set_worker         = SetWorker, 
+		multi_threaded     = MT, 
+		ref                = Ref, 
+		vsns               = Vsns,
+		nfilters           = NF,
+		note_store         = NoteStore,
+		mib_server         = MS, 
+		net_if             = NetIf, 
+		net_if_mod         = NetIfMod, 
+		backup             = Backup,
+		disco              = Disco,
+		mibs_cache_request = MCR,
+		gb_max_vbs         = ?DEFAULT_GB_MAX_VBS}, 
+    {ok, S2};
 
 code_change(_Vsn, S, _Extra) ->
     {ok, S}.
@@ -1454,7 +1565,7 @@ worker_start(Dict) ->
 %%     worker_stop(Pid, infinity).
 
 worker_stop(Pid, Timeout) when is_pid(Pid) ->
-    Pid ! terminate, 
+    Pid ! ?mk_terminate_wreq(), 
     receive 
 	{'EXIT', Pid, normal} ->
 	    ok
@@ -1591,9 +1702,11 @@ invalidate_ca_cache() ->
 %% 
 %%-----------------------------------------------------------------
 
-spawn_thread(Vsn, Pdu, PduMS, ACMData, Address, Extra) ->
+%% This functions spawns a temporary worker process, 
+%% that evaluates one request and then silently exits. 
+spawn_thread(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra) ->
     Dict = get(),
-    Args = [Vsn, Pdu, PduMS, ACMData, Address, Extra, Dict], 
+    Args = [Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra, Dict], 
     proc_lib:spawn_link(?MODULE, handle_pdu, Args).
 
 spawn_trap_thread(TrapRec, NotifyName, ContextName, Recv, Vbs, 
@@ -1611,7 +1724,7 @@ do_send_trap(TrapRec, NotifyName, ContextName, Recv, Vbs,
 do_send_trap(TrapRec, NotifyName, ContextName, Recv, Vbs, 
 	     LocalEngineID, ExtraInfo, Dict) ->
     lists:foreach(fun({Key, Val}) -> put(Key, Val) end, Dict),
-    put(sname,trap_sender_short_name(get(sname))),
+    put(sname, trap_sender_short_name(get(sname))),
     ?vlog("starting",[]),
     snmpa_trap:send_trap(TrapRec, NotifyName, ContextName, Recv, Vbs, 
 			 LocalEngineID, ExtraInfo, get(net_if)).
@@ -1623,58 +1736,122 @@ worker(Master, Dict) ->
     worker_loop(Master).
 
 worker_loop(Master) ->
-    receive
-	{Vsn, Pdu, PduMS, ACMData, Address, Extra} ->
-	    ?vtrace("worker_loop -> received request", []),
-	    handle_pdu(Vsn, Pdu, PduMS, ACMData, Address, Extra),
-	    Master ! worker_available;
-
-	%% We don't trap EXITs!
-	{TrapRec, NotifyName, ContextName, Recv, Vbs} -> 
-	    ?vtrace("worker_loop -> send trap:"
-		    "~n   ~p", [TrapRec]),
-	    snmpa_trap:send_trap(TrapRec, NotifyName, 
-				 ContextName, Recv, Vbs, 
-				 ?DEFAULT_NOTIF_EXTRA_INFO, 
-				 get(net_if)),
-	    Master ! worker_available;
-
-	%% We don't trap EXITs!
-	{send_trap, 
-	 TrapRec, NotifyName, ContextName, Recv, Vbs, LocalEngineID} -> 
-	    ?vtrace("worker_loop -> send trap:"
-		    "~n   ~p", [TrapRec]),
-	    snmpa_trap:send_trap(TrapRec, NotifyName, 
-				 ContextName, Recv, Vbs, 
-				 LocalEngineID, ?DEFAULT_NOTIF_EXTRA_INFO, 
-				 get(net_if)),
-	    Master ! worker_available;
-
-	{send_trap, 
-	 TrapRec, NotifyName, ContextName, Recv, Vbs, LocalEngineID, ExtraInfo} -> 
-	    ?vtrace("worker_loop -> send trap:"
-		    "~n   ~p", [TrapRec]),
-	    snmpa_trap:send_trap(TrapRec, NotifyName, 
-				 ContextName, Recv, Vbs, 
-				 LocalEngineID, ExtraInfo, 
-				 get(net_if)),
-	    Master ! worker_available;
-
-	{verbosity, Verbosity} ->
-	    put(verbosity,snmp_verbosity:validate(Verbosity));
-
-	terminate ->
-	    exit(normal);
-
-	_X ->
-	    %% ignore
-	    ok
-
-    after 30000 ->
-	    %% This is to assure that the worker process leaves a
-	    %% possibly old version of this module.
-	    ok
-    end,
+    Res = 
+	receive
+	    #wrequest{cmd  = handle_pdu, 
+		      info = Info} = Req ->
+		?vtrace("worker_loop -> received handle_pdu request with"
+			"~n   Info: ~p", [Info]),
+		Vsn      = proplists:get_value(vsn,        Info),
+		Pdu      = proplists:get_value(pdu,        Info),
+		PduMS    = proplists:get_value(pdu_ms,     Info),
+		ACMData  = proplists:get_value(acm_data,   Info),
+		Address  = proplists:get_value(addr,       Info),
+		GbMaxVBs = proplists:get_value(gb_max_vbs, Info),
+		Extra    = proplists:get_value(extra,      Info),
+		HandlePduRes = 
+		    try 
+			begin
+			    handle_pdu2(Vsn, Pdu, PduMS, ACMData, Address, 
+					GbMaxVBs, Extra)
+			end
+		    catch 
+			T:E ->
+			    exit({worker_crash, Req, T, E, 
+				  erlang:get_stacktrace()})
+		    end,
+		Master ! worker_available,
+		HandlePduRes; % For debugging...
+	    
+	    
+	    #wrequest{cmd  = send_trap, 
+		      info = Info} = Req ->
+		?vtrace("worker_loop -> received send_trap request with"
+			"~n   Info: ~p", [Info]),
+		TrapRec       = proplists:get_value(trap_rec,        Info),
+		NotifyName    = proplists:get_value(notify_name,     Info),
+		ContextName   = proplists:get_value(context_name,    Info),
+		Recv          = proplists:get_value(receiver,        Info),
+		Vbs           = proplists:get_value(varbinds,        Info),
+		LocalEngineID = proplists:get_value(local_engine_id, Info),
+		Extra         = proplists:get_value(extra,           Info),
+		SendTrapRes = 
+		    try
+			begin
+			    snmpa_trap:send_trap(TrapRec, NotifyName, 
+						 ContextName, Recv, Vbs, 
+						 LocalEngineID, Extra, 
+						 get(net_if))
+			end
+		    catch 
+			T:E ->
+			    exit({worker_crash, Req, T, E, 
+				  erlang:get_stacktrace()})
+		    end,
+		Master ! worker_available, 
+		SendTrapRes; % For debugging...
+	    
+	    
+	    #wrequest{cmd  = verbosity, 
+		      info = Info} ->
+		Verbosity = proplists:get_value(verbosity, Info),
+		put(verbosity, snmp_verbosity:validate(Verbosity));
+	    
+	    
+	    #wrequest{cmd  = terminate} ->
+		?vtrace("worker_loop -> received terminate request", []),
+		exit(normal);
+	    
+	    
+	    %% *************************************************************
+	    %% 
+	    %%         Kept for backward compatibillity reasons
+	    %% 
+	    %% *************************************************************
+	    
+	    {Vsn, Pdu, PduMS, ACMData, Address, Extra} ->
+		?vtrace("worker_loop -> received request", []),
+		handle_pdu2(Vsn, Pdu, PduMS, ACMData, Address, 
+			    ?DEFAULT_GB_MAX_VBS, Extra),
+		Master ! worker_available;
+	    
+	    %% We don't trap exits!
+	    {TrapRec, NotifyName, ContextName, Recv, Vbs} -> 
+		?vtrace("worker_loop -> send trap:"
+			"~n   ~p", [TrapRec]),
+		snmpa_trap:send_trap(TrapRec, NotifyName, 
+				     ContextName, Recv, Vbs, get(net_if)),
+		Master ! worker_available;
+	    
+	    %% We don't trap exits!
+	    {send_trap, 
+	     TrapRec, NotifyName, ContextName, Recv, Vbs, LocalEngineID,
+	     ExtraInfo} -> 
+		?vtrace("worker_loop -> send trap:"
+			"~n   ~p", [TrapRec]),
+		snmpa_trap:send_trap(TrapRec, NotifyName, 
+				     ContextName, Recv, Vbs, 
+				     LocalEngineID, ExtraInfo, 
+				     get(net_if)),
+		Master ! worker_available;
+	    
+	    {verbosity, Verbosity} ->
+		put(verbosity, snmp_verbosity:validate(Verbosity));
+	    
+	    terminate ->
+		exit(normal);
+	    
+	    _X ->
+		%% ignore
+		ignore_unknown
+	
+	after 30000 ->
+		%% This is to assure that the worker process leaves a
+		%% possibly old version of this module.
+		ok
+	end,
+    ?vtrace("worker_loop -> wrap with"
+	    "~n   ~p", [Res]),
     ?MODULE:worker_loop(Master).
 
 
@@ -1682,42 +1859,52 @@ worker_loop(Master) ->
 %%-----------------------------------------------------------------
 
 handle_snmp_pdu(true, Vsn, Pdu, PduMS, ACMData, Address, Extra, 
-		#state{multi_threaded = false} = S) ->
+		#state{multi_threaded = false, 
+		       gb_max_vbs     = GbMaxVBs} = S) ->
     ?vtrace("handle_snmp_pdu -> single-thread agent",[]),
-    handle_pdu(Vsn, Pdu, PduMS, ACMData, Address, Extra),
+    handle_pdu2(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra),
     S;
 handle_snmp_pdu(true, Vsn, #pdu{type = 'set-request'} = Pdu, PduMS, 
 		ACMData, Address, Extra, 
 		#state{set_worker = Worker} = S) ->
     ?vtrace("handle_snmp_pdu -> multi-thread agent: "
 	    "send set-request to main worker",[]),
-    Worker ! {Vsn, Pdu, PduMS, ACMData, Address, Extra}, 
+    WRequest = ?mk_pdu_wreq(Vsn, Pdu, PduMS, ACMData, Address, infinity, Extra),
+    Worker ! WRequest, 
     S#state{worker_state = busy};
 handle_snmp_pdu(true, Vsn, Pdu, PduMS, 
 		ACMData, Address, Extra, 
-		#state{worker_state = busy} = S) ->
+		#state{worker_state = busy, 
+		       gb_max_vbs   = GbMaxVBs} = S) ->
     ?vtrace("handle_snmp_pdu -> multi-thread agent: "
 	    "main worker busy - create new worker",[]),
-    spawn_thread(Vsn, Pdu, PduMS, ACMData, Address, Extra),
+    spawn_thread(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra),
     S;
 handle_snmp_pdu(true, Vsn, Pdu, PduMS, ACMData, Address, Extra, 
-		#state{worker = Worker} = S) ->
+		#state{worker     = Worker, 
+		       gb_max_vbs = GbMaxVBs} = S) ->
     ?vtrace("handle_snmp_pdu -> multi-thread agent: "
 	    "send to main worker",[]),
-    Worker ! {Vsn, Pdu, PduMS, ACMData, Address, Extra}, 
+    WRequest = ?mk_pdu_wreq(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra),
+    Worker ! WRequest, 
     S#state{worker_state = busy};
 handle_snmp_pdu(_, _Vsn, _Pdu, _PduMS, _ACMData, _Address, _Extra, S) ->
     S.
 
 
 %% Called via the spawn_thread function
+%% <BACKWARD-COMPAT>
 handle_pdu(Vsn, Pdu, PduMS, ACMData, Address, Extra, Dict) ->
+    handle_pdu(Vsn, Pdu, PduMS, ACMData, Address, ?DEFAULT_GB_MAX_VBS, Extra, 
+	       Dict).
+%% </BACKWARD-COMPAT>
+handle_pdu(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra, Dict) ->
     lists:foreach(fun({Key, Val}) -> put(Key, Val) end, Dict),
     put(sname, pdu_handler_short_name(get(sname))),
     ?vlog("new worker starting",[]),
-    handle_pdu(Vsn, Pdu, PduMS, ACMData, Address, Extra).
+    handle_pdu2(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra).
 
-handle_pdu(Vsn, Pdu, PduMS, ACMData, Address, Extra) ->
+handle_pdu2(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra) ->
     %% OTP-3324
     AuthMod = get(auth_module),
     case AuthMod:init_check_access(Pdu, ACMData) of
@@ -1726,7 +1913,8 @@ handle_pdu(Vsn, Pdu, PduMS, ACMData, Address, Extra) ->
 		  "~n   MibView:     ~p"
 		  "~n   ContextName: ~p", [MibView, ContextName]),
 	    AgentData = cheat(ACMData, Address, ContextName),
-	    do_handle_pdu(MibView, Vsn, Pdu, PduMS, ACMData, AgentData, Extra);
+	    do_handle_pdu(MibView, Vsn, Pdu, PduMS, ACMData, AgentData, 
+			  GbMaxVBs, Extra);
 	{error, Reason} ->
 	    ?vlog("handle_pdu -> error:"
 		  "~n   Reason: ~p", [Reason]),
@@ -1740,16 +1928,19 @@ handle_pdu(Vsn, Pdu, PduMS, ACMData, Address, Extra) ->
     end.
 
 do_handle_pdu(MibView, Vsn, Pdu, PduMS, 
-	      ACMData, {Community, Address, ContextName}, Extra) ->
+	      ACMData, {Community, Address, ContextName}, 
+	      GbMaxVBs, Extra) ->
     
     put(net_if_data, Extra),
+
     RePdu = process_msg(MibView, Vsn, Pdu, PduMS, Community, 
-			Address, ContextName),
+			Address, ContextName, GbMaxVBs),
 
     ?vtrace("do_handle_pdu -> processed:"
 	    "~n   RePdu: ~p", [RePdu]),
-    get(net_if) ! {snmp_response, Vsn, RePdu, 
-		   RePdu#pdu.type, ACMData, Address, Extra}.
+    NetIf = get(net_if), 
+    NetIf ! {snmp_response, Vsn, RePdu, 
+	     RePdu#pdu.type, ACMData, Address, Extra}.
 
 
 handle_acm_error(Vsn, Reason, Pdu, ACMData, Address, Extra) ->
@@ -1950,9 +2141,9 @@ do_handle_send_trap(S, TrapRec, NotifyName, ContextName, Recv, Varbinds,
 	master_agent ->
 	    %% Send to main worker
 	    ?vtrace("do_handle_send_trap -> send to main worker",[]),
-	    S#state.worker ! {send_trap, 
-			      TrapRec, NotifyName, ContextName, Recv, Vbs,
-			      LocalEngineID, ExtraInfo},
+	    S#state.worker ! ?mk_send_trap_wreq(TrapRec, NotifyName, 
+						ContextName, Recv, Vbs,
+						LocalEngineID, ExtraInfo),
 	    {ok, S#state{worker_state = busy}}
     end.
     
@@ -2292,17 +2483,18 @@ handle_mib_of(MibServer, Oid) ->
 %% Func: process_msg/7
 %% Returns: RePdu
 %%-----------------------------------------------------------------
-process_msg(MibView, Vsn, Pdu, PduMS, Community, {Ip, Udp}, ContextName) ->
+process_msg(MibView, Vsn, Pdu, PduMS, Community, {Ip, Udp}, ContextName, 
+	    GbMaxVBs) ->
     #pdu{request_id = ReqId} = Pdu,
     put(snmp_address, {tuple_to_list(Ip), Udp}),
     put(snmp_request_id, ReqId),
     put(snmp_community, Community),
     put(snmp_context, ContextName),
     ?vtrace("process ~p",[Pdu#pdu.type]),
-    process_pdu(Pdu, PduMS, Vsn, MibView).
+    process_pdu(Pdu, PduMS, Vsn, MibView, GbMaxVBs).
 
 process_pdu(#pdu{type='get-request', request_id = ReqId, varbinds=Vbs},
-	    _PduMS, Vsn, MibView) ->
+	    _PduMS, Vsn, MibView, _GbMaxVBs) ->
     ?vtrace("get ~p",[ReqId]),
     Res = get_err(do_get(MibView, Vbs, false)),
     ?vtrace("get result: "
@@ -2323,12 +2515,12 @@ process_pdu(#pdu{type='get-request', request_id = ReqId, varbinds=Vbs},
     make_response_pdu(ReqId, ErrStatus, ErrIndex, Vbs, ResponseVarbinds);
 
 process_pdu(#pdu{type = 'get-next-request', request_id = ReqId, varbinds = Vbs},
-	    _PduMS, Vsn, MibView) ->
+	    _PduMS, Vsn, MibView, _GbMaxVBs) ->
     ?vtrace("process get-next-request -> entry with"
 	    "~n   ReqId:   ~p"
 	    "~n   Vbs:     ~p"
 	    "~n   MibView: ~p",[ReqId, Vbs, MibView]),
-    Res = get_err(do_get_next(MibView, Vbs)),
+    Res = get_err(do_get_next(MibView, Vbs, infinity)),
     ?vtrace("get-next result: "
 	    "~n   ~p",[Res]),
     {ErrStatus, ErrIndex, ResVarbinds} = 
@@ -2345,11 +2537,15 @@ process_pdu(#pdu{type = 'get-next-request', request_id = ReqId, varbinds = Vbs},
 	    "~n   ~p",[ResponseVarbinds]),
     make_response_pdu(ReqId, ErrStatus, ErrIndex, Vbs, ResponseVarbinds);
 
-process_pdu(#pdu{type = 'get-bulk-request',request_id = ReqId,varbinds = Vbs,
-		 error_status = NonRepeaters, error_index = MaxRepetitions},
-	    PduMS, _Vsn, MibView)->
+process_pdu(#pdu{type         = 'get-bulk-request',
+		 request_id   = ReqId,
+		 varbinds     = Vbs,
+		 error_status = NonRepeaters, 
+		 error_index  = MaxRepetitions},
+	    PduMS, _Vsn, MibView, GbMaxVBs) ->
     {ErrStatus, ErrIndex, ResponseVarbinds} = 
-	get_err(do_get_bulk(MibView,NonRepeaters,MaxRepetitions,PduMS,Vbs)),
+	get_err(do_get_bulk(MibView, NonRepeaters, MaxRepetitions, PduMS, Vbs, 
+			    GbMaxVBs)),
     ?vtrace("get-bulk final result: "
 	    "~n   Error status:     ~p"
 	    "~n   Error index:      ~p"
@@ -2358,7 +2554,7 @@ process_pdu(#pdu{type = 'get-bulk-request',request_id = ReqId,varbinds = Vbs,
     make_response_pdu(ReqId, ErrStatus, ErrIndex, Vbs, ResponseVarbinds);
 
 process_pdu(#pdu{type = 'set-request', request_id = ReqId, varbinds = Vbs},
-	    _PduMS, Vsn, MibView)->
+	    _PduMS, Vsn, MibView, _GbMaxVbs)->
     Res = do_set(MibView, Vbs),
     ?vtrace("set result: "
 	    "~n   ~p",[Res]),
@@ -2415,7 +2611,8 @@ validate_next_v1_2([Vb | _Vbs], _MibView, _Res)
     {noSuchName, Vb#varbind.org_index};
 validate_next_v1_2([Vb | Vbs], MibView, Res)
   when Vb#varbind.variabletype =:= 'Counter64' ->
-    case validate_next_v1(do_get_next(MibView, [mk_next_oid(Vb)]), MibView) of
+    case validate_next_v1(
+	   do_get_next(MibView, [mk_next_oid(Vb)], infinity), MibView) of
 	{noError, 0, [NVb]} ->
 	    validate_next_v1_2(Vbs, MibView, [NVb | Res]);
 	{Error, Index, _OrgVb} ->
@@ -2888,59 +3085,97 @@ validate_tab_res(_TooMany, [], Mfa, _Res, I) ->
 %%      that this really matters, since many nexts across the same
 %%      subagent must be considered to be very rare.
 %%-----------------------------------------------------------------
-do_get_next(MibView, UnsortedVarbinds) ->
-    SortedVarbinds = oid_sort_varbindlist(UnsortedVarbinds),
-    next_loop_varbinds([], SortedVarbinds, MibView, [], []).
 
-oid_sort_varbindlist(Vbs) ->
+%% It may be a bit agressive to check this already, 
+%% but since it is a security measure, it makes sense.
+do_get_next(_MibView, UnsortedVarbinds, GbMaxVBs) 
+  when (is_integer(GbMaxVBs) andalso (length(UnsortedVarbinds) > GbMaxVBs)) ->
+    {tooBig, 0, []}; % What is the correct index in this case?
+do_get_next(MibView, UnsortedVBs, GbMaxVBs) ->
+    ?vt("do_get_next -> entry when"
+ 	"~n   MibView:          ~p"
+ 	"~n   UnsortedVBs: ~p", [MibView, UnsortedVBs]),
+    SortedVBs = oid_sort_vbs(UnsortedVBs),
+    ?vt("do_get_next -> "
+ 	"~n   SortedVBs: ~p", [SortedVBs]),
+    next_loop_varbinds([], SortedVBs, MibView, [], [], GbMaxVBs).
+
+oid_sort_vbs(Vbs) ->
     lists:keysort(#varbind.oid, Vbs).
 
+next_loop_varbinds(_, Vbs, _MibView, Res, _LAVb, GbMaxVBs) 
+  when (is_integer(GbMaxVBs) andalso 
+	((length(Vbs) + length(Res)) > GbMaxVBs)) ->
+    {tooBig, 0, []}; % What is the correct index in this case?
+
 %% LAVb is Last Accessible Vb
-next_loop_varbinds([], [Vb | Vbs], MibView, Res, LAVb) ->
+next_loop_varbinds([], [Vb | Vbs], MibView, Res, LAVb, GbMaxVBs) ->
     ?vt("next_loop_varbinds -> entry when"
  	"~n   Vb:      ~p"
  	"~n   MibView: ~p", [Vb, MibView]),
     case varbind_next(Vb, MibView) of
 	endOfMibView ->
+	    ?vt("next_loop_varbind -> endOfMibView", []),
 	    RVb = if LAVb =:= [] -> Vb;
 		     true -> LAVb
 		  end,
 	    NewVb = RVb#varbind{variabletype = 'NULL', value = endOfMibView},
-	    next_loop_varbinds([], Vbs, MibView, [NewVb | Res], []);
+	    next_loop_varbinds([], Vbs, MibView, [NewVb | Res], [], GbMaxVBs);
+
 	{variable, ME, VarOid} when ((ME#me.access =/= 'not-accessible') andalso 
 				     (ME#me.access =/= 'write-only') andalso 
 				     (ME#me.access =/= 'accessible-for-notify')) -> 
+	    ?vt("next_loop_varbind -> variable: "
+		"~n   ME:     ~p"
+		"~n   VarOid: ~p", [ME, VarOid]),
 	    case try_get_instance(Vb, ME) of
 		{value, noValue, _NoSuchSomething} ->
+		    ?vt("next_loop_varbind -> noValue", []),
 		    %% Try next one
-		    NewVb = Vb#varbind{oid = VarOid, value = 'NULL'},
-		    next_loop_varbinds([], [NewVb | Vbs], MibView, Res, []);
+		    NewVb = Vb#varbind{oid   = VarOid, 
+				       value = 'NULL'},
+		    next_loop_varbinds([], [NewVb | Vbs], MibView, Res, [], 
+				       GbMaxVBs);
 		{value, Type, Value} ->
-		    NewVb = Vb#varbind{oid = VarOid, variabletype = Type,
-				       value = Value},
-		    next_loop_varbinds([], Vbs, MibView, [NewVb | Res], []);
+		    ?vt("next_loop_varbind -> value"
+			"~n   Type:  ~p"
+			"~n   Value: ~p", [Type, Value]),
+		    NewVb = Vb#varbind{oid          = VarOid, 
+				       variabletype = Type,
+				       value        = Value},
+		    next_loop_varbinds([], Vbs, MibView, [NewVb | Res], [],
+				       GbMaxVBs);
 		{error, ErrorStatus} ->
 		    ?vdebug("next loop varbinds:"
 			    "~n   ErrorStatus: ~p",[ErrorStatus]),
 		    {ErrorStatus, Vb#varbind.org_index, []}
 	    end;
 	{variable, _ME, VarOid} -> 
+	    ?vt("next_loop_varbind -> variable: "
+		"~n   VarOid: ~p", [VarOid]),
 	    RVb = if LAVb =:= [] -> Vb;
 		     true -> LAVb
 		  end,
 	    NewVb = Vb#varbind{oid = VarOid, value = 'NULL'},
-	    next_loop_varbinds([], [NewVb | Vbs], MibView, Res, RVb);
+	    next_loop_varbinds([], [NewVb | Vbs], MibView, Res, RVb, GbMaxVBs);
 	{table, TableOid, TableRestOid, ME} ->
+	    ?vt("next_loop_varbind -> table: "
+		"~n   TableOid:     ~p"
+		"~n   TableRestOid: ~p"
+		"~n   ME:           ~p", [TableOid, TableRestOid, ME]),
 	    next_loop_varbinds({table, TableOid, ME,
 				[{tab_oid(TableRestOid), Vb}]},
-			       Vbs, MibView, Res, []);
+			       Vbs, MibView, Res, [], GbMaxVBs);
 	{subagent, SubAgentPid, SAOid} ->
+	    ?vt("next_loop_varbind -> subagent: "
+		"~n   SubAgentPid: ~p"
+		"~n   SAOid:       ~p", [SubAgentPid, SAOid]),
 	    NewVb = Vb#varbind{variabletype = 'NULL', value = 'NULL'},
 	    next_loop_varbinds({subagent, SubAgentPid, SAOid, [NewVb]},
-			       Vbs, MibView, Res, [])
+			       Vbs, MibView, Res, [], GbMaxVBs)
     end;
 next_loop_varbinds({table, TableOid, ME, TabOids},
-		   [Vb | Vbs], MibView, Res, _LAVb) ->
+		   [Vb | Vbs], MibView, Res, _LAVb, GbMaxVBs) ->
     ?vt("next_loop_varbinds(table) -> entry with"
  	"~n   TableOid: ~p"
  	"~n   Vb:       ~p", [TableOid, Vb]),
@@ -2948,13 +3183,14 @@ next_loop_varbinds({table, TableOid, ME, TabOids},
 	{table, TableOid, TableRestOid, _ME} ->
 	    next_loop_varbinds({table, TableOid, ME,
 				[{tab_oid(TableRestOid), Vb} | TabOids]},
-			       Vbs, MibView, Res, []);
+			       Vbs, MibView, Res, [], GbMaxVBs);
 	_ ->
 	    case get_next_table(ME, TableOid, TabOids, MibView) of
 		{ok, TabRes, TabEndOfTabVbs} ->
 		    NewVbs = lists:append(TabEndOfTabVbs, [Vb | Vbs]),
 		    NewRes = lists:append(TabRes, Res),
-		    next_loop_varbinds([], NewVbs, MibView, NewRes, []);
+		    next_loop_varbinds([], NewVbs, MibView, NewRes, [], 
+				       GbMaxVBs);
 		{ErrorStatus, OrgIndex} ->
 		    ?vdebug("next loop varbinds: next varbind"
 			    "~n   ErrorStatus: ~p"
@@ -2964,7 +3200,7 @@ next_loop_varbinds({table, TableOid, ME, TabOids},
 	    end
     end;
 next_loop_varbinds({table, TableOid, ME, TabOids},
-		   [], MibView, Res, _LAVb) ->
+		   [], MibView, Res, _LAVb, GbMaxVBs) ->
     ?vt("next_loop_varbinds(table) -> entry with"
 	"~n   TableOid: ~p", [TableOid]),
     case get_next_table(ME, TableOid, TabOids, MibView) of
@@ -2973,7 +3209,8 @@ next_loop_varbinds({table, TableOid, ME, TabOids},
 		"~n   TabRes:         ~p"
 		"~n   TabEndOfTabVbs: ~p", [TabRes, TabEndOfTabVbs]),
 	    NewRes = lists:append(TabRes, Res),
-	    next_loop_varbinds([], TabEndOfTabVbs, MibView, NewRes, []);
+	    next_loop_varbinds([], TabEndOfTabVbs, MibView, NewRes, [], 
+			       GbMaxVBs);
 	{ErrorStatus, OrgIndex} ->
 	    ?vdebug("next loop varbinds: next table"
 		    "~n   ErrorStatus: ~p"
@@ -2982,7 +3219,7 @@ next_loop_varbinds({table, TableOid, ME, TabOids},
 	    {ErrorStatus, OrgIndex, []}
     end;
 next_loop_varbinds({subagent, SAPid, SAOid, SAVbs},
-		   [Vb | Vbs], MibView, Res, _LAVb) ->
+		   [Vb | Vbs], MibView, Res, _LAVb, GbMaxVBs) ->
     ?vt("next_loop_varbinds(subagent) -> entry with"
 	"~n   SAPid: ~p"
 	"~n   SAOid: ~p"
@@ -2991,13 +3228,14 @@ next_loop_varbinds({subagent, SAPid, SAOid, SAVbs},
 	{subagent, _SubAgentPid, SAOid} ->
 	    next_loop_varbinds({subagent, SAPid, SAOid,
 				[Vb | SAVbs]},
-			       Vbs, MibView, Res, []);
+			       Vbs, MibView, Res, [], GbMaxVBs);
 	_ ->
 	    case get_next_sa(SAPid, SAOid, SAVbs, MibView) of
 		{ok, SARes, SAEndOfMibViewVbs} ->
 		    NewVbs = lists:append(SAEndOfMibViewVbs, [Vb | Vbs]),
 		    NewRes = lists:append(SARes, Res),
-		    next_loop_varbinds([], NewVbs, MibView, NewRes, []);
+		    next_loop_varbinds([], NewVbs, MibView, NewRes, [], 
+				       GbMaxVBs);
 		{noSuchName, OrgIndex} ->
 		    %% v1 reply, treat this Vb as endOfMibView, and try again
 		    %% for the others.
@@ -3010,12 +3248,14 @@ next_loop_varbinds({subagent, SAPid, SAOid, SAVbs},
 			    case lists:delete(EVb, SAVbs) of
 				[] ->
 				    next_loop_varbinds([], [EndOfVb, Vb | Vbs],
-						       MibView, Res, []);
+						       MibView, Res, [],
+						       GbMaxVBs);
 				TryAgainVbs ->
 				    next_loop_varbinds({subagent, SAPid, SAOid,
 							TryAgainVbs},
 						       [EndOfVb, Vb | Vbs],
-						       MibView, Res, [])
+						       MibView, Res, [],
+						       GbMaxVBs)
 			    end;
 			false ->
 			    %% bad index from subagent
@@ -3031,14 +3271,15 @@ next_loop_varbinds({subagent, SAPid, SAOid, SAVbs},
 	    end
     end;
 next_loop_varbinds({subagent, SAPid, SAOid, SAVbs},
-		   [], MibView, Res, _LAVb) ->
+		   [], MibView, Res, _LAVb, GbMaxVBs) ->
      ?vt("next_loop_varbinds(subagent) -> entry with"
 	 "~n   SAPid: ~p"
 	 "~n   SAOid: ~p", [SAPid, SAOid]),
     case get_next_sa(SAPid, SAOid, SAVbs, MibView) of
 	{ok, SARes, SAEndOfMibViewVbs} ->
 	    NewRes = lists:append(SARes, Res),
-	    next_loop_varbinds([], SAEndOfMibViewVbs, MibView, NewRes, []);
+	    next_loop_varbinds([], SAEndOfMibViewVbs, MibView, NewRes, [],
+			       GbMaxVBs);
 	{noSuchName, OrgIndex} ->
 	    %% v1 reply, treat this Vb as endOfMibView, and try again for
 	    %% the others.
@@ -3049,11 +3290,13 @@ next_loop_varbinds({subagent, SAPid, SAOid, SAVbs},
 					  value = {endOfMibView, NextOid}},
 		    case lists:delete(EVb, SAVbs) of
 			[] ->
-			    next_loop_varbinds([], [EndOfVb], MibView, Res, []);
+			    next_loop_varbinds([], [EndOfVb], MibView, Res, [],
+					       GbMaxVBs);
 			TryAgainVbs ->
 			    next_loop_varbinds({subagent, SAPid, SAOid,
 						TryAgainVbs},
-					       [EndOfVb], MibView, Res, [])
+					       [EndOfVb], MibView, Res, [],
+					       GbMaxVBs)
 		    end;
 		false ->
 		    %% bad index from subagent
@@ -3066,12 +3309,15 @@ next_loop_varbinds({subagent, SAPid, SAOid, SAVbs},
  		    [ErrorStatus,OrgIndex]),
  	    {ErrorStatus, OrgIndex, []}
     end;
-next_loop_varbinds([], [], _MibView, Res, _LAVb) ->
+next_loop_varbinds([], [], _MibView, Res, _LAVb, _GbMaxVBs) ->
     ?vt("next_loop_varbinds -> entry when done", []),
     {noError, 0, Res}.
 
 try_get_instance(_Vb, #me{mfa = {M, F, A}, asn1_type = ASN1Type}) ->
-    ?vtrace("try get instance from <~p,~p,~p>",[M,F,A]),
+    ?vtrace("try_get_instance -> entry with"
+	    "~n   M: ~p"
+	    "~n   F: ~p"
+	    "~n   A: ~p", [M,F,A]),
     Result = (catch dbg_apply(M, F, [get | A])),
     % mib shall return {value, <a-nice-value-within-range>} |
     % {noValue, noSuchName} (v1) | 
@@ -3082,6 +3328,7 @@ try_get_instance(_Vb, #me{mfa = {M, F, A}, asn1_type = ASN1Type}) ->
 tab_oid([]) -> [0];
 tab_oid(X) -> X.
 
+
 %%-----------------------------------------------------------------
 %% Perform a next, using the varbinds Oid if value is simple
 %% value. If value is {endOf<something>, NextOid}, use NextOid.
@@ -3328,22 +3575,30 @@ next_oid(Oid) ->
 
 %%%-----------------------------------------------------------------
 %%% 5. GET-BULK REQUEST
+%%% 
+%%% In order to prevent excesses in reply sizes there are two 
+%%% preventive methods in place. One is to check that the encode
+%%% size does not exceed Max PDU size (this is mentioned in the
+%%% standard). The other is a simple VBs limit. That is, the 
+%%% resulting response cannot contain more then this number of VBs.
 %%%-----------------------------------------------------------------
-do_get_bulk(MibView, NonRepeaters, MaxRepetitions, PduMS, Varbinds) ->
-    ?vtrace("do get bulk: start with"
+
+do_get_bulk(MibView, NonRepeaters, MaxRepetitions, PduMS, Varbinds, GbMaxVBs) ->
+    ?vtrace("do_get_bulk -> entry with"
 	    "~n   MibView:        ~p"
 	    "~n   NonRepeaters:   ~p"
 	    "~n   MaxRepetitions: ~p"
 	    "~n   PduMS:          ~p"
-	    "~n   Varbinds:       ~p",
-	    [MibView, NonRepeaters, MaxRepetitions, PduMS, Varbinds]),
+	    "~n   Varbinds:       ~p"
+	    "~n   GbMaxVBs:       ~p",
+	    [MibView, NonRepeaters, MaxRepetitions, PduMS, Varbinds, GbMaxVBs]),
     {NonRepVbs, RestVbs} = split_vbs(NonRepeaters, Varbinds, []),
-    ?vt("do get bulk -> split: "
+    ?vt("do_get_bulk -> split: "
 	"~n   NonRepVbs: ~p"
 	"~n   RestVbs:   ~p", [NonRepVbs, RestVbs]),
-    case do_get_next(MibView, NonRepVbs) of
-	{noError, 0, UResNonRepVbs} -> 
-	    ?vt("do get bulk -> next: "
+    case do_get_next(MibView, NonRepVbs, GbMaxVBs) of
+	{noError, 0, UResNonRepVbs} ->
+	    ?vt("do_get_bulk -> next noError: "
 		"~n   UResNonRepVbs: ~p", [UResNonRepVbs]),
 	    ResNonRepVbs = lists:keysort(#varbind.org_index, UResNonRepVbs),
 	    %% Decode the first varbinds, produce a reversed list of
@@ -3353,11 +3608,12 @@ do_get_bulk(MibView, NonRepeaters, MaxRepetitions, PduMS, Varbinds) ->
 		    user_err("failed encoding varbind ~w:~n~p", [Idx, Reason]),
                     {genErr, Idx, []};
                 {SizeLeft, Res} when is_integer(SizeLeft) and is_list(Res) ->
- 		    ?vtrace("do get bulk -> encoded: "
+ 		    ?vtrace("do_get_bulk -> encoded: "
 			    "~n   SizeLeft: ~p"
 			    "~n   Res:      ~w", [SizeLeft, Res]),
 		    case (catch do_get_rep(SizeLeft, MibView, MaxRepetitions,
-					   RestVbs, Res)) of
+					   RestVbs, Res, 
+					   length(UResNonRepVbs), GbMaxVBs)) of
 			{error, Idx, Reason} ->
 			    user_err("failed encoding varbind ~w:~n~p", 
 				     [Idx, Reason]),
@@ -3366,6 +3622,10 @@ do_get_bulk(MibView, NonRepeaters, MaxRepetitions, PduMS, Varbinds) ->
 			    ?vtrace("do get bulk -> Res: "
 				    "~n   ~w", [Res]),
 			    {noError, 0, conv_res(Res)};
+			{noError, 0, Data} = OK ->
+			    ?vtrace("do get bulk -> OK: "
+				    "~n   length(Data): ~w", [length(Data)]),
+			    OK;
 			Else ->
 			    ?vtrace("do get bulk -> Else: "
 				    "~n   ~w", [Else]),
@@ -3374,6 +3634,7 @@ do_get_bulk(MibView, NonRepeaters, MaxRepetitions, PduMS, Varbinds) ->
 		Res when is_list(Res) ->
 		    {noError, 0, conv_res(Res)}
 	    end;
+
 	{ErrorStatus, Index, _} ->
 	    ?vdebug("do get bulk: "
 		    "~n   ErrorStatus: ~p"
@@ -3423,11 +3684,12 @@ enc_vbs(SizeLeft, Vbs) ->
 	  end,
     lists:foldl(Fun, {SizeLeft, []}, Vbs).
 
-do_get_rep(Sz, MibView, MaxRepetitions, Varbinds, Res) 
+do_get_rep(Sz, MibView, MaxRepetitions, Varbinds, Res, GbNumVBs, GbMaxVBs) 
   when MaxRepetitions >= 0 ->
-    do_get_rep(Sz, MibView, 0, MaxRepetitions, Varbinds, Res);
-do_get_rep(Sz, MibView, _MaxRepetitions, Varbinds, Res) ->
-    do_get_rep(Sz, MibView, 0, 0, Varbinds, Res).
+    do_get_rep(Sz, MibView, 0, MaxRepetitions, Varbinds, Res, 
+	       GbNumVBs, GbMaxVBs);
+do_get_rep(Sz, MibView, _MaxRepetitions, Varbinds, Res, GbNumVBs, GbMaxVBs) ->
+    do_get_rep(Sz, MibView, 0, 0, Varbinds, Res, GbNumVBs, GbMaxVBs).
 
 conv_res(ResVarbinds) ->
     conv_res(ResVarbinds, []).
@@ -3436,22 +3698,30 @@ conv_res([VbListOfBytes | T], Bytes) ->
 conv_res([], Bytes) ->
     Bytes.
 
-do_get_rep(_Sz, _MibView, Max, Max, _, Res) ->
+%% The only other value, then a positive integer, is infinity.
+do_get_rep(_Sz, _MibView, Count, Max, _, _Res, GbNumVBs, GbMaxVBs) 
+  when (is_integer(GbMaxVBs) andalso (GbNumVBs > GbMaxVBs)) ->
+    ?vinfo("Max Get-BULK VBs limit (~w) exceeded (~w) when:"
+	   "~n   Count: ~p"
+	   "~n   Max:   ~p", [GbMaxVBs, GbNumVBs, Count, Max]),
+    {tooBig, 0, []};
+do_get_rep(_Sz, _MibView, Max, Max, _, Res, _GbNumVBs, _GbMaxVBs) ->
     ?vt("do_get_rep -> done when: "
 	"~n   Res: ~p", [Res]),
     {noError, 0, conv_res(Res)};
-do_get_rep(Sz, MibView, Count, Max, Varbinds, Res) -> 
+do_get_rep(Sz, MibView, Count, Max, Varbinds, Res, GbNumVBs, GbMaxVBs) -> 
     ?vt("do_get_rep -> entry when: "
 	"~n   Sz:    ~p"
 	"~n   Count: ~p"
 	"~n   Res:   ~w", [Sz, Count, Res]),
-    case try_get_bulk(Sz, MibView, Varbinds) of
+    case try_get_bulk(Sz, MibView, Varbinds, GbMaxVBs) of
 	{noError, NextVarbinds, SizeLeft, Res2} -> 
 	    ?vt("do_get_rep -> noError: "
 		"~n   SizeLeft: ~p"
 		"~n   Res2:     ~p", [SizeLeft, Res2]),
 	    do_get_rep(SizeLeft, MibView, Count+1, Max, NextVarbinds,
-		       Res2 ++ Res);
+		       Res2 ++ Res, 
+		       GbNumVBs + length(Varbinds), GbMaxVBs);
 	{endOfMibView, _NextVarbinds, _SizeLeft, Res2} -> 
 	    ?vt("do_get_rep -> endOfMibView: "
 		"~n   Res2: ~p", [Res2]),
@@ -3463,22 +3733,29 @@ do_get_rep(Sz, MibView, Count, Max, Varbinds, Res) ->
 	    {ErrorStatus, Index, []}
     end.
 
-try_get_bulk(Sz, MibView, Varbinds) -> 
+org_index_sort_vbs(Vbs) ->
+    lists:keysort(#varbind.org_index, Vbs).
+
+try_get_bulk(Sz, MibView, Varbinds, GbMaxVBs) -> 
     ?vt("try_get_bulk -> entry with"
-	"~n   Sz: ~w", [Sz]),
-    case do_get_next(MibView, Varbinds) of
+	"~n   Sz:       ~w"
+	"~n   MibView:  ~w"
+	"~n   Varbinds: ~w", [Sz, MibView, Varbinds]),
+    case do_get_next(MibView, Varbinds, GbMaxVBs) of
 	{noError, 0, UNextVarbinds} -> 
-	    ?vt("try_get_bulk -> noError", []),
-	    NextVarbinds = lists:keysort(#varbind.org_index, UNextVarbinds),
+	    ?vt("try_get_bulk -> noError: "
+		"~n   UNextVarbinds: ~p", [UNextVarbinds]),
+	    NextVarbinds = org_index_sort_vbs(UNextVarbinds),
 	    case (catch enc_vbs(Sz, NextVarbinds)) of
 		{error, Idx, Reason} ->
 		    user_err("failed encoding varbind ~w:~n~p", [Idx, Reason]),
-		    ?vtrace("try_get_bulk -> error: "
+		    ?vtrace("try_get_bulk -> encode error: "
 			    "~n   Idx:    ~p"
 			    "~n   Reason: ~p", [Idx, Reason]),
 		    {genErr, Idx};
-		{SizeLeft, Res} when is_integer(SizeLeft) andalso is_list(Res) ->
-		    ?vt("try get bulk -> "
+		{SizeLeft, Res} when is_integer(SizeLeft) andalso 
+				     is_list(Res) ->
+		    ?vt("try get bulk -> encode ok: "
 			"~n   SizeLeft: ~w"
 			"~n   Res:      ~w", [SizeLeft, Res]),
 		    {check_end_of_mibview(NextVarbinds),
@@ -3489,9 +3766,9 @@ try_get_bulk(Sz, MibView, Varbinds) ->
 		    {endOfMibView, [], 0, Res}
 	    end;
 	{ErrorStatus, Index, _} ->
-	    ?vt("try get bulk: "
+	    ?vt("try_get_bulk -> error: "
 		"~n   ErrorStatus: ~p"
-		"~n   Index:       ~p",[ErrorStatus, Index]),
+		"~n   Index:       ~p", [ErrorStatus, Index]),
 	    {ErrorStatus, Index}
     end.
 
@@ -3632,9 +3909,8 @@ get_err({ErrC, ErrI, Vbs}) ->
     {get_err_i(ErrC), ErrI, Vbs}.
 
 get_err_i(noError) -> noError;
-get_err_i(S) -> 
-    ?vtrace("convert '~p' to 'genErr'",[S]),
-    genErr.
+get_err_i(tooBig) -> tooBig;    % OTP-9700 
+get_err_i(ES) -> ?vtrace("convert ErrorStatus '~p' to 'genErr'", [ES]), genErr.
 
 v2err_to_v1err(noError) ->            noError;
 v2err_to_v1err(noAccess) ->           noSuchName;
@@ -4144,6 +4420,9 @@ get_multi_threaded(Opts) ->
 get_versions(Opts) ->
     get_option(versions, Opts, [v1,v2,v3]).
 
+get_gb_max_vbs(Opts) ->
+    get_option(gb_max_vbs, Opts, infinity).
+
 get_note_store_opt(Opts) ->
     get_option(note_store, Opts, []).
 
diff --git a/lib/snmp/src/agent/snmpa_internal.hrl b/lib/snmp/src/agent/snmpa_internal.hrl
index 20a36cc118..c435b519d9 100644
--- a/lib/snmp/src/agent/snmpa_internal.hrl
+++ b/lib/snmp/src/agent/snmpa_internal.hrl
@@ -26,6 +26,15 @@
 -define(DEFAULT_LOCAL_ENGINE_ID,  snmp_framework_mib:get_engine_id()). 
 -define(DEFAULT_NOTIF_EXTRA_INFO, {snmpa_default_notification_extra_info}).
 
+%% -- Max number of VBs in a Get-BULK response --
+%% (( The default value, 1000, is *way* more   ))
+%% (( then there is room for in a normal pdu   ))
+%% (( (unless the max pdu size has been        ))
+%% (( cranked way up), so this value should    ))
+%% (( suffice as "infinity" without actually   ))
+%% (( causing memory issues for the VM ...     ))
+-define(DEFAULT_GB_MAX_VBS, 1000).
+
 -define(snmpa_info(F, A),    ?snmp_info("agent",    F, A)).
 -define(snmpa_warning(F, A), ?snmp_warning("agent", F, A)).
 -define(snmpa_error(F, A),   ?snmp_error("agent",   F, A)).
diff --git a/lib/snmp/src/agent/snmpa_mib_lib.erl b/lib/snmp/src/agent/snmpa_mib_lib.erl
index 078e681945..3c94cc8095 100644
--- a/lib/snmp/src/agent/snmpa_mib_lib.erl
+++ b/lib/snmp/src/agent/snmpa_mib_lib.erl
@@ -61,23 +61,23 @@ table_del_row({Tab, Db} = TabDb, Key) ->
 get_table(NameDb, FOI) ->
     (catch get_table(NameDb, FOI, [], [])).
 
-get_table(NameDb, FOI, Oid, Acc) ->
-    case table_next(NameDb, Oid) of
+get_table(NameDb, FOI, Key, Acc) ->
+    case table_next(NameDb, Key) of
         endOfTable ->
             ?vdebug("end of table",[]),
             {ok, lists:reverse(Acc)};
-        Oid ->
+        Key ->
             %% Crap, circular ref
-            ?vinfo("cyclic reference: ~w -> ~w", [Oid,Oid]),
-            throw({error, {cyclic_db_reference, Oid, Acc}});
-        NextOid ->
-            ?vtrace("get row for oid ~w", [NextOid]),
-            case table_get_row(NameDb, NextOid, FOI) of
+            ?vinfo("cyclic reference: ~w -> ~w", [Key, Key]),
+            throw({error, {cyclic_db_reference, Key, Acc}});
+        NextKey ->
+            ?vtrace("get row for key ~w", [NextKey]),
+            case table_get_row(NameDb, NextKey, FOI) of
                 undefined -> 
-		    throw({error, {invalid_rowindex, NextOid, Acc}});
+		    throw({error, {invalid_rowindex, NextKey, Acc}});
                 Row ->
                     ?vtrace("row: ~w", [Row]),
-		    get_table(NameDb, FOI, NextOid, [{NextOid, Row}|Acc])
+		    get_table(NameDb, FOI, NextKey, [{NextKey, Row}|Acc])
             end
     end.
     
diff --git a/lib/snmp/src/agent/snmpa_supervisor.erl b/lib/snmp/src/agent/snmpa_supervisor.erl
index 5ef5914e18..7a9c214e0d 100644
--- a/lib/snmp/src/agent/snmpa_supervisor.erl
+++ b/lib/snmp/src/agent/snmpa_supervisor.erl
@@ -176,8 +176,8 @@ init([AgentType, Opts]) ->
       "~n   AgentType: ~p"
       "~n   Opts:      ~p", [AgentType, Opts]),
 
-    put(sname, asup),
-    put(verbosity,get_verbosity(Opts)),
+    put(sname,     asup),
+    put(verbosity, get_verbosity(Opts)),
 
     ?vlog("starting",[]),
 
@@ -203,7 +203,12 @@ init([AgentType, Opts]) ->
     Vsns = get_opt(versions, Opts, [v1,v2,v3]),
     ?vdebug("[agent table] store versions: ~p",[Vsns]),
     ets:insert(snmp_agent_table, {versions, Vsns}),
-    
+
+    %% -- Max number of VBs in a Get-BULK response --
+    GbMaxVBs = get_gb_max_vbs(Opts),
+    ?vdebug("[agent table] Get-BULK max VBs: ~p", [GbMaxVBs]),
+    ets:insert(snmp_agent_table, {gb_max_vbs, GbMaxVBs}),
+
     %% -- DB-directory --
     DbDir = get_opt(db_dir, Opts),
     ?vdebug("[agent table] store db_dir: ~n   ~p",[DbDir]),
@@ -377,7 +382,8 @@ init([AgentType, Opts]) ->
 		     {versions,               Vsns},
 		     {net_if,                 NiOpts},
 		     {mib_server,             MibsOpts},
-		     {note_store,             NsOpts}|
+		     {note_store,             NsOpts},
+		     {gb_max_vbs,             GbMaxVBs} |
 		     get_opt(master_agent_options, Opts, [])],
 		     
 		AgentSpec =
@@ -542,6 +548,32 @@ get_verbosity(Opts) ->
 get_agent_type(Opts) ->
     get_opt(agent_type, Opts, master).
 
+
+%% We validate this option! This should really be done for all
+%% options, but it is beyond the scope of this ticket, OTP-9700.
+
+get_gb_max_vbs(Opts) ->
+    Validate = 
+	fun(GbMaxVBs) 
+	   when ((is_integer(GbMaxVBs) andalso (GbMaxVBs > 0)) orelse
+		 (GbMaxVBs =:= infinity)) ->
+		ok;
+	   (_) ->
+		error
+	end,
+    get_option(gb_max_vbs, ?DEFAULT_GB_MAX_VBS, Validate, Opts).
+
+get_option(Key, Default, Validate, Opts) 
+  when is_list(Opts) andalso is_function(Validate) ->
+    Value = get_opt(Key, Opts, Default),
+    case Validate(Value) of
+	ok ->
+	    Value;
+	error ->
+	    exit({bad_option, Key, Value})
+    end.
+    
+
 get_opt(Key, Opts) ->
     snmp_misc:get_option(Key, Opts).
 
diff --git a/lib/snmp/src/agent/snmpa_trap.erl b/lib/snmp/src/agent/snmpa_trap.erl
index 5b579efc13..994d926224 100644
--- a/lib/snmp/src/agent/snmpa_trap.erl
+++ b/lib/snmp/src/agent/snmpa_trap.erl
@@ -352,11 +352,26 @@ send_trap(TrapRec, NotifyName, ContextName, Recv, Vbs, ExtraInfo, NetIf) ->
     send_trap(TrapRec, NotifyName, ContextName, Recv, Vbs, 
 	      LocalEngineID, ExtraInfo, NetIf).
 
+%% The agent normally does not care about the result, 
+%% but since it can be usefull when debugging, add 
+%% some info when we fail to send the trap(s).
 send_trap(TrapRec, NotifyName, ContextName, Recv, Vbs, LocalEngineID, 
 	  ExtraInfo, NetIf) ->
-    (catch do_send_trap(TrapRec, NotifyName, ContextName, Recv, Vbs, 
-			LocalEngineID, ExtraInfo, NetIf)).
-
+    try 
+	begin
+	    do_send_trap(TrapRec, NotifyName, ContextName, Recv, Vbs, 
+			 LocalEngineID, ExtraInfo, NetIf)
+	end
+    catch
+	T:E ->
+	    Info = [{args, [TrapRec, NotifyName, ContextName, 
+			    Recv, Vbs, LocalEngineID, ExtraInfo, NetIf]},
+		    {tag,  T},
+		    {err,  E},
+		    {stacktrace, erlang:get_stacktrace()}],
+	    {error, {failed_sending_trap, Info}}
+    end.
+     
 do_send_trap(TrapRec, NotifyName, ContextName, Recv, Vbs, 
 	     LocalEngineID, ExtraInfo, NetIf) ->
     VarbindList = make_varbind_list(Vbs),
diff --git a/lib/snmp/src/agent/snmpa_vacm.erl b/lib/snmp/src/agent/snmpa_vacm.erl
index 2cbc11d280..dadcf32543 100644
--- a/lib/snmp/src/agent/snmpa_vacm.erl
+++ b/lib/snmp/src/agent/snmpa_vacm.erl
@@ -62,6 +62,13 @@ get_mib_view(ViewType, SecModel, SecName, SecLevel, ContextName) ->
 
 %% Follows the procedure in rfc2275
 auth(ViewType, SecModel, SecName, SecLevel, ContextName) ->
+    ?vtrace("auth -> entry with"
+	    "~n   ViewType:    ~p"
+	    "~n   SecModel:    ~p"
+	    "~n   SecName:     ~p"
+	    "~n   SecLevel:    ~p"
+	    "~n   ContextName: ~p", 
+	    [ViewType, SecModel, SecName, SecLevel, ContextName]),
     % 3.2.1 - Check that the context is known to us
     ?vdebug("check that the context (~p) is known to us",[ContextName]),
     case snmp_view_based_acm_mib:vacmContextTable(get, ContextName,
@@ -74,7 +81,7 @@ auth(ViewType, SecModel, SecName, SecLevel, ContextName) ->
     end,
     % 3.2.2 - Check that the SecModel and SecName is valid
     ?vdebug("check that SecModel (~p) and SecName (~p) is valid",
-	    [SecModel,SecName]),
+	    [SecModel, SecName]),
     GroupName = 
 	case snmp_view_based_acm_mib:get(vacmSecurityToGroupTable, 
 					 [SecModel, length(SecName) | SecName],
@@ -111,6 +118,8 @@ check_auth(Res)                 -> {ok, Res}.
 %% key in the table >= ViewIndex.
 %%-----------------------------------------------------------------
 get_mib_view(ViewName) ->
+    ?vtrace("get_mib_view -> entry with"
+	    "~n   ViewName: ~p", [ViewName]),
     ViewKey = [length(ViewName) | ViewName],
     case snmp_view_based_acm_mib:table_next(vacmViewTreeFamilyTable,
 					    ViewKey) of
@@ -202,6 +211,13 @@ backup(BackupDir) ->
 
 %% Ret: {ok, ViewName} | {error, Reason}
 get_view_name(ViewType, GroupName, ContextName, SecModel, SecLevel) ->
+    ?vtrace("get_view_name -> entry with"
+	    "~n   ViewType:    ~p"
+	    "~n   GroupName:   ~p"
+	    "~n   ContextName: ~p"
+	    "~n   SecModel:    ~p"
+	    "~n   SecLevel:    ~p", 
+	    [ViewType, GroupName, ContextName, SecModel, SecLevel]),
     GroupKey = [length(GroupName) | GroupName],
     case get_access_row(GroupKey, ContextName, SecModel, SecLevel) of
 	undefined ->
diff --git a/lib/snmp/src/app/snmp.appup.src b/lib/snmp/src/app/snmp.appup.src
index 589b728dc5..254e697039 100644
--- a/lib/snmp/src/app/snmp.appup.src
+++ b/lib/snmp/src/app/snmp.appup.src
@@ -22,68 +22,109 @@
 %% ----- U p g r a d e -------------------------------------------------------
 
  [
+  {"4.21.5",
+   [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmp_target_mib, soft_purge, soft_purge, [snmpa_mib_lib]}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {load_module, snmpa_trap, soft_purge, soft_purge, []}, 
+    {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+    {update,      snmpa_agent, soft, soft_purge, soft_purge, []}
+   ]
+  },
   {"4.21.4", 
    [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmp_target_mib, soft_purge, soft_purge, [snmpa_mib_lib]}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {load_module, snmpa_trap, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+
     {load_module, snmp_generic_mnesia, soft_purge, soft_purge, []}, 
     {load_module, snmp_view_based_acm_mib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
-    {update, snmpa_agent, soft, soft_purge, soft_purge, []}
+    {update,      snmpa_agent, soft, soft_purge, soft_purge, []}
    ]
   }, 
   {"4.21.3", 
    [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmp_target_mib, soft_purge, soft_purge, [snmpa_mib_lib]}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {load_module, snmpa_trap, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+
     {load_module, snmp_generic_mnesia, soft_purge, soft_purge, []}, 
     {load_module, snmp_view_based_acm_mib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
-    {update, snmpa_local_db, soft, soft_purge, soft_purge, []}, 
-    {update, snmpa_agent, soft, soft_purge, soft_purge, []}
+    {update,      snmpa_local_db, soft, soft_purge, soft_purge, []}, 
+    {update,      snmpa_agent, soft, soft_purge, soft_purge, []}
    ]
   }, 
   {"4.21.2", 
    [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmp_target_mib, soft_purge, soft_purge, [snmpa_mib_lib]}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+
     {load_module, snmp_view_based_acm_mib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
     {load_module, snmpa_mpd, soft_purge, soft_purge, []}, 
     {load_module, snmpa_set_lib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_trap, soft_purge, soft_purge, []}, 
     {load_module, snmp_generic_mnesia, soft_purge, soft_purge, []}, 
-    {update, snmpa_local_db, soft, soft_purge, soft_purge, []},
-    {update, snmpa_agent, soft, soft_purge, soft_purge, []}
+    {update,      snmpa_local_db, soft, soft_purge, soft_purge, []},
+    {update,      snmpa_agent, soft, soft_purge, soft_purge, []}
    ]
   }, 
   {"4.21.1", 
    [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmp_target_mib, soft_purge, soft_purge, [snmpa_mib_lib]}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+
     {load_module, snmp_view_based_acm_mib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
     {load_module, snmpa_mpd, soft_purge, soft_purge, []}, 
     {load_module, snmpa_set_lib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_trap, soft_purge, soft_purge, []}, 
     {load_module, snmp_generic_mnesia, soft_purge, soft_purge, []}, 
-    {update, snmpa_local_db, soft, soft_purge, soft_purge, []},
-    {update, snmpa_agent, soft, soft_purge, soft_purge, []}, 
-    {update, snmp_note_store, soft, soft_purge, soft_purge, []}
+    {update,      snmpa_local_db, soft, soft_purge, soft_purge, []},
+    {update,      snmpa_agent, soft, soft_purge, soft_purge, []}, 
+    {update,      snmp_note_store, soft, soft_purge, soft_purge, []}
    ]
   }, 
   {"4.21", 
    [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+
     {load_module, snmp_view_based_acm_mib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
     {load_module, snmpa_mpd, soft_purge, soft_purge, []}, 
     {load_module, snmpa_set_lib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_trap, soft_purge, soft_purge, []}, 
-    {load_module, snmp_target_mib, soft_purge, soft_purge, []},
+    {load_module, snmp_target_mib, soft_purge, soft_purge, [snmpa_mib_lib]},
     {load_module, snmp_generic_mnesia, soft_purge, soft_purge, []}, 
-    {update, snmpa_local_db, soft, soft_purge, soft_purge, []},
-    {update, snmpa_agent, soft, soft_purge, soft_purge, []}, 
-    {update, snmp_note_store, soft, soft_purge, soft_purge, []}
+    {update,      snmpa_local_db, soft, soft_purge, soft_purge, []},
+    {update,      snmpa_agent, soft, soft_purge, soft_purge, []}, 
+    {update,      snmp_note_store, soft, soft_purge, soft_purge, []}
    ]
   }, 
   {"4.20.1", 
    [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+
     {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
     {load_module, snmpa_set_lib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_trap, soft_purge, soft_purge, []}, 
-    {load_module, snmp_target_mib, soft_purge, soft_purge, []}, 
+    {load_module, snmp_target_mib, soft_purge, soft_purge, [snmpa_mib_lib]}, 
     {load_module, snmp_view_based_acm_mib, soft_purge, soft_purge, []}, 
     {load_module, snmpm, soft_purge, soft_purge, 
      [snmpm_server, snmpm_config, snmp_config]}, 
@@ -96,22 +137,27 @@
     {load_module, snmpa_conf, soft_purge, soft_purge, [snmp_config]}, 
     {update, snmp_note_store, soft, soft_purge, soft_purge, []}, 
     {load_module, snmp_generic_mnesia, soft_purge, soft_purge, []}, 
-    {update, snmpa_local_db, soft, soft_purge, soft_purge, []},
-    {update, snmpa_agent, soft, soft_purge, soft_purge, [snmpa_mpd]}, 
-    {update, snmpm_config, soft, soft_purge, soft_purge, [snmp_conf]}, 
-    {update, snmpm_server, soft, soft_purge, soft_purge, 
+    {update,      snmpa_local_db, soft, soft_purge, soft_purge, []},
+    {update,      snmpa_agent, soft, soft_purge, soft_purge, [snmpa_mpd]}, 
+    {update,      snmpm_config, soft, soft_purge, soft_purge, [snmp_conf]}, 
+    {update,      snmpm_server, soft, soft_purge, soft_purge, 
      [snmpm_net_if, snmpm_mpd, snmpm_config]}, 
-    {update, snmpm_net_if, soft, soft_purge, soft_purge, 
+    {update,      snmpm_net_if, soft, soft_purge, soft_purge, 
      [snmp_conf, snmpm_mpd, snmpm_config]}
    ]
   }, 
   {"4.20", 
    [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+
     {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
     {load_module, snmpa_set_lib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_trap, soft_purge, soft_purge, []}, 
     {load_module, snmp_view_based_acm_mib, soft_purge, soft_purge, []}, 
-    {load_module, snmp_target_mib, soft_purge, soft_purge, [snmp_conf]}, 
+    {load_module, snmp_target_mib, soft_purge, soft_purge, 
+     [snmpa_mib_lib, snmp_conf]}, 
     {load_module, snmpm, soft_purge, soft_purge, 
      [snmpm_server, snmpm_config, snmp_config]}, 
     {load_module, snmp_conf, soft_purge, soft_purge, []}, 
@@ -123,12 +169,12 @@
     {load_module, snmpa_conf, soft_purge, soft_purge, [snmp_config]}, 
     {update, snmp_note_store, soft, soft_purge, soft_purge, []}, 
     {load_module, snmp_generic_mnesia, soft_purge, soft_purge, []}, 
-    {update, snmpa_local_db, soft, soft_purge, soft_purge, []},
-    {update, snmpa_agent, soft, soft_purge, soft_purge, [snmpa_mpd]}, 
-    {update, snmpm_config, soft, soft_purge, soft_purge, [snmp_conf]}, 
-    {update, snmpm_server, soft, soft_purge, soft_purge, 
+    {update,      snmpa_local_db, soft, soft_purge, soft_purge, []},
+    {update,      snmpa_agent, soft, soft_purge, soft_purge, [snmpa_mpd]}, 
+    {update,      snmpm_config, soft, soft_purge, soft_purge, [snmp_conf]}, 
+    {update,      snmpm_server, soft, soft_purge, soft_purge, 
      [snmpm_net_if, snmpm_mpd, snmpm_config]}, 
-    {update, snmpm_net_if, soft, soft_purge, soft_purge, 
+    {update,      snmpm_net_if, soft, soft_purge, soft_purge, 
      [snmp_conf, snmpm_mpd, snmpm_config]}
    ]
   }
@@ -137,8 +183,25 @@
 %% ------D o w n g r a d e ---------------------------------------------------
 
  [
+  {"4.21.5",
+   [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmp_target_mib, soft_purge, soft_purge, [snmpa_mib_lib]}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {load_module, snmpa_trap, soft_purge, soft_purge, []}, 
+    {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+    {update,      snmpa_agent, soft, soft_purge, soft_purge, []}
+   ]
+  },
   {"4.21.4", 
    [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmp_target_mib, soft_purge, soft_purge, [snmpa_mib_lib]}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {load_module, snmpa_trap, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+
     {load_module, snmp_generic_mnesia, soft_purge, soft_purge, []}, 
     {load_module, snmp_view_based_acm_mib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
@@ -147,6 +210,12 @@
   }, 
   {"4.21.3", 
    [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmp_target_mib, soft_purge, soft_purge, [snmpa_mib_lib]}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {load_module, snmpa_trap, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+
     {load_module, snmp_generic_mnesia, soft_purge, soft_purge, []}, 
     {load_module, snmp_view_based_acm_mib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
@@ -156,6 +225,11 @@
   }, 
   {"4.21.2", 
    [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmp_target_mib, soft_purge, soft_purge, [snmpa_mib_lib]}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+
     {load_module, snmp_view_based_acm_mib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
     {load_module, snmpa_mpd, soft_purge, soft_purge, []}, 
@@ -168,6 +242,11 @@
   }, 
   {"4.21.1", 
    [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmp_target_mib, soft_purge, soft_purge, [snmpa_mib_lib]}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+
     {load_module, snmp_view_based_acm_mib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
     {load_module, snmpa_mpd, soft_purge, soft_purge, []}, 
@@ -181,6 +260,10 @@
   }, 
   {"4.21", 
    [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+
     {load_module, snmp_view_based_acm_mib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
     {load_module, snmpa_mpd, soft_purge, soft_purge, []}, 
@@ -195,6 +278,10 @@
   }, 
   {"4.20.1", 
    [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+
     {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
     {load_module, snmpa_set_lib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_trap, soft_purge, soft_purge, []}, 
@@ -222,6 +309,10 @@
   }, 
   {"4.20", 
    [
+    {load_module, snmpa, soft_purge, soft_purge, []}, 
+    {load_module, snmpa_mib_lib, soft_purge, soft_purge, []}, 
+    {update,      snmpa_supervisor, soft, soft_purge, soft_purge, []}, 
+
     {load_module, snmpa_vacm, soft_purge, soft_purge, []}, 
     {load_module, snmpa_set_lib, soft_purge, soft_purge, []}, 
     {load_module, snmpa_trap, soft_purge, soft_purge, []},