www.bmc.com
Integrating PATROL with
SNMP
(Simple Network Management Protocol)
Eric Anderson
BMC Software Developer Connection
1
© 1999 BMC SOFTWARE, INC.
3/17/99
SNMP - Overview
 Network


protocols
Transport layer (UDP/IP)
Message protocol (ASN.1)
 Versions



SNMPv1
SNMPv2
SNMPv3
 OSI

2
network management implementation
CMIP - CMOT
© 1999 BMC SOFTWARE, INC. 3/17/99
SNMP : Underlying Transport
UDP/IP implications (unsafe)
unreliable



no confirmation or guarantee
order uncertain
may duplicate
unsecure



3
No authentication on transport layer
No verification of origin (message spoofing)
No integrity (message can be tampered with)
© 1999 BMC SOFTWARE, INC. 3/17/99
SNMP message protocol
ASN.1 (iso 8824 - “abstract notation one”)


Does information exchange with well defined syntax
comparable in functionality with XML
BER (iso 8825)


4
Basic Encoding Rules
TLV (Type, Length, Value) encoding
© 1999 BMC SOFTWARE, INC. 3/17/99
Management Operations
 Get,

Get Next, Set
for SNMPv1
 Get
Bulk (for SNMPv2)
 Unsolicited Traps from Agent (v1)
 Informs (v3 and v3)
5
© 1999 BMC SOFTWARE, INC. 3/17/99
Get Request handling
 Agent gets request from mgr
 listens on specific port : typically 161
 receives PDU : request ID + OID
 Lookup of OID in memory
 Agent sends get response
 request ID
 OID
 error status + index
 value
 Similar for get-next operation
 returns next OID in tree
6
© 1999 BMC SOFTWARE, INC. 3/17/99
Trap sending
SNMP Agent determines when
 7 predefined Generic trap types (0-6)

6=enterpriseSpecfic
 Send
via to port 162 on trap receiving machine
 Trap destinations has to be configured

7
Patrol : /snmp/piV1m_list
© 1999 BMC SOFTWARE, INC. 3/17/99
Listening for traps
Only one process can listen on a port
That means only one trap listener per system !
Solution :
 PATROL : trap demultiplexer (Dietmar Hildebrand)
 No PATROL : (DIY= write your own)
8
© 1999 BMC SOFTWARE, INC. 3/17/99
MIB (Management Information Base)
 The


textual description of MIB layout
Written in SMI : Structure of Managment Information
 SMI


9
MIB file
(the MIB definition language)
Support for multiple datatypes
Support for data definitions : indexed tables, structures,
values,...
© 1999 BMC SOFTWARE, INC. 3/17/99
NAMING in MIB
1 iso
Naming hierarchy
unique identifier, down to the 3 org
instance of any object
6 dod
1.3.6.1.4.1.1031 is the OID of
1 internet
the BMC Software subtree
2
mgmt
4 private
1 enterprises
enterpriseID
442
peer 1031 Company X
BMC
Whatever you like
10
© 1999 BMC SOFTWARE, INC. 3/17/99
The SNMP Manager
What is an SNMP manager ?
Components :



11
present MIB info (display MIB files)
send requests
listen for traps
© 1999 BMC SOFTWARE, INC. 3/17/99
The SNMP Agent
What is an SNMP agent ?
 Components :



12
MIB (the MIB in memory)
request handling
trap sending
© 1999 BMC SOFTWARE, INC. 3/17/99
Multiple SNMP Agents on 1 system
Conflict : only 1 process can listen on a port
Solutions :



SMUX (SNMP Multiplexer)
AgentX - Agent Extensibility (rfc 2741)
Emanate (proprietary SNMP Research)
Sub agent
Master
Agent
Sub agent
161
Sub agent
13
© 1999 BMC SOFTWARE, INC. 3/17/99
SNMPv3
 New
standardization effort for v2 with enhanced
Security

14
User Based security model (rfc 2574)
© 1999 BMC SOFTWARE, INC. 3/17/99
SNMP References
SNMP v1 RFCs
 1155
SMI
 1157
protocol
 1212
Concise MIB
 1213
MIB2
 1215
traps
SNMP v2 RFCs
 historical
See also : The Simple Web
http://snmp.cs.utwente.nl/
15
© 1999 BMC SOFTWARE, INC. 3/17/99
SNMP v2C RFCs
 1902-1907
SNMP v3 RFCs
 1905-1907
 2571-2575
 2578-2580
http://www.ietf.org
www.bmc.com
PATROL & SNMP
16
© 1999 BMC SOFTWARE, INC.
3/17/99
PATROL SNMP – Windows NT
PATROL Console
Management Station
Port 161
SNMP Agent (Master)
Windows Service
Port 8161
Applications
Applications
Uses Windows
SNMP API
Applications
Uses Windows
SNMP API
Applications
Uses Windows
SNMP API
Uses Windows SNMP API
17
PATROL SNMP Master Agent
Snmpget()
© 1999 BMC SOFTWARE, INC. 3/17/99
SMUX
Port 191
PATROL Agent
With
SNMP Sub Agent
Access
Method
SNMP
Runtime
Application
Encapsulator
process
PATROL SNMP – UNIX
PATROL Console
Management Station
Port 161
SNMP Agent (Master)
Port 8161
Snmpget()
PATROL SNMP Master Agent
SMUX
Port 191
Applications
Applications
Uses Windows
SNMP API
Applications
Uses Windows
SNMP API
Applications
Uses Windows
SNMP API
Dynamically loaded into
Agent space
18
© 1999 BMC SOFTWARE, INC. 3/17/99
PATROL Agent
With
SNMP Sub Agent
Access
Method
SNMP
Runtime
Application
Encapsulator
process
Master agent confusion
Only needed when accessing PATROL MIB
data !!
Not needed for :
 receiving traps
 sending traps
 get/set/walk/... operations
19
© 1999 BMC SOFTWARE, INC. 3/17/99
PATROL Agent as SNMP Manager
 Receiving
traps
 Getting information from other SNMP agents
 No Master Agent is needed for this !
20
© 1999 BMC SOFTWARE, INC. 3/17/99
Configuring PATROL for SNMP
Set the port number and community name for the PATROL SNMP
Master Agent
 The PATROL SNMP Master Agent/Sub-Agent model is based on an
industry standard known as SMUX that allows one or more SNMP SubAgents to connect to a single SNMP Master Agent using a TCP SMUX
port (TCP port 199 by default).
Turn on the SNMP support variable.
 agent configuration variable /snmp/agent_auto_start is set to yes,
the PATROL Agent starts the SNMP Sub-Agent when the PATROL
Agent is started
Add the SNMP manager to the list of interested SNMPV1 managers.
 The SNMP management console needs to know how to recognize PATROL
traps, and what to do about them. On some consoles it involves
configuration of internal rules and tables. In others it may involve
configuring the "trapd.conf" configuration file.
Configure events to send SNMP traps.
21
© 1999 BMC SOFTWARE, INC. 3/17/99
SNMP support variable(s)
The SNMPStart parameter is defined within each <platform>.km. The “out of box” default setting for this parameter
is the active state. If active, SNMPStart launches the PATROL SNMP Master Agent (snmpmagt) if it is not
started already. SNMPStart then starts the SNMP Sub-Agent.
The configuration of the PATROL SNMP Sub Agent is controlled by the values contained in the PATROL
configuration file.
On UNIX, it is $PATROL_HOME/lib/config.default
On Windows NT, it is %PATROL_HOME%\lib\ config.default
The important variables are:
"/snmp/support" = { REPLACE="yes" },
"/snmp/agent_auto_start" = { REPLACE="yes" },
"/snmp/default_port"
= { REPLACE="161" },
"/snmp/master_agent_port" = { REPLACE="1161" },
"/snmp/trap_port" = { REPLACE="162" },
"/snmp/sysName" = { REPLACE = "unknown" },
"/snmp/sysContact" = { REPLACE = "http://www.bmc.com" },
"/snmp/sysLocation" = { REPLACE = "BMC Software Inc." },
"/snmp/piV1m_list" = { REPLACE="" },
22
© 1999 BMC SOFTWARE, INC. 3/17/99
Master agent configuration
 See


file ./lib/snmpmagt.cfg
UNIX : default port 1161, community public
NT : default port 1161, community public
 No
need for BMC master agent if SMUX master
agent available (eg. AIX)
 What about HP ?


23
They use emanate master agent = proprietary
Run 2 master agents, one on 161 (default) and one on 1161
(Patrol)
© 1999 BMC SOFTWARE, INC. 3/17/99
PATROL SNMP Master Agent
The configuration of the PATROL SNMP Master Agent is controlled by the values contained in the
PATROL SNMP Master Agent configuration file.
On UNIX, it is $PATROL_HOME/lib/snmpmagt.cfg.
On Windows NT, it is %PATROL_HOME%\lib\snmpmagt.cfg.
•# GRAMMAR:
•#
•#
•#
•#
•#
•#
•#
•#
•#
•#
•#
•#
•#
•#
•#
•#
•#
MANAGER
manager
[SEND [ALL | NO ] TRAPS
[TO PORT <#>]
[WITH COMMUNITY <name>]]
COMMUNITY
<name>
ALLOW op [,op]* [OPERATIONS]
[USE encrypt ENCRYPTION]
[MEMBERS
<manager> [,<manager>]* ]
manager ::=
<hostname> | ipaddr
where: hostname is defined in /etc/hosts
ipaddr ::=
op ::=
encrypt ::=
<a.b.c.d>
ALL | GET | SET | TRAP
NO
COMMUNITY public
ALLOW ALL OPERATIONS
USE NO ENCRYPTION
TRANSPORT ordinary SNMP
OVER UDP SOCKET
AT PORT 1161
24
© 1999 BMC SOFTWARE, INC. 3/17/99
PATROL Agent as SNMP sub agent
 Ability
to send traps
 Has an accessible MIB
 To access MIB, the master agent must be set up
correctly
25
© 1999 BMC SOFTWARE, INC. 3/17/99
Sending traps
 Automatically



From event catalogs
Trap destinations : piV1m_List ( + /snmp/trapMibTable=yes)
Filter possibility (see config.default for filter options)
 From


26
:
PSL
snmp_trap_send : full control
snmp_trap_raise_std_trap : uses piV1m_List
© 1999 BMC SOFTWARE, INC. 3/17/99
www.bmc.com
The PATROL MIB
27
© 1999 BMC SOFTWARE, INC.
3/17/99
MIB Object Groups
iso (1)
org (3)
dod (6)
internet (1)
mgmt (2)
Mib-2 (1)
system (1)
private (4)
enterprises (1)
bmc (1031)
28
© 1999 BMC SOFTWARE, INC. 3/17/99
MIB Tables – Indexing a Table
OS>%PSL print(snmp_walk("sess47", "1.3.6.1.4.1.1031.1.1.1.6.1.1")."\n");
Table
Column Index
Row Index
29
OID
1.3.6.1.4.1.1031.1.1.1.6.1.1.0
1.3.6.1.4.1.1031.1.1.1.6.1.1.1
1.3.6.1.4.1.1031.1.1.1.6.1.1.2
1.3.6.1.4.1.1031.1.1.1.6.1.1.3
1.3.6.1.4.1.1031.1.1.1.6.1.1.4
1.3.6.1.4.1.1031.1.1.1.6.1.1.5
1.3.6.1.4.1.1031.1.1.1.6.1.1.6
1.3.6.1.4.1.1031.1.1.1.6.1.1.7
1.3.6.1.4.1.1031.1.1.1.6.1.1.8
1.3.6.1.4.1.1031.1.1.1.6.1.1.9
1.3.6.1.4.1.1031.1.1.1.6.1.1.10
1.3.6.1.4.1.1031.1.1.1.6.1.1.11
1.3.6.1.4.1.1031.1.1.1.6.1.1.12
1.3.6.1.4.1.1031.1.1.1.6.1.1.13
1.3.6.1.4.1.1031.1.1.1.6.1.1.14
1.3.6.1.4.1.1031.1.1.1.6.1.1.15
1.3.6.1.4.1.1031.1.1.1.6.1.1.16
1.3.6.1.4.1.1031.1.1.1.6.1.1.17
1.3.6.1.4.1.1031.1.1.1.6.1.1.18
© 1999 BMC SOFTWARE, INC. 3/17/99
StrLen
2
11
9
10
3
4
10
6
6
7
3
6
7
7
8
3
4
5
3
Type
string
string
string
string
string
string
string
string
string
string
string
string
string
string
string
string
string
string
string
applicationName
HP
PATROLAGENT
SNMP_Test
COLLECTORS
CPU
DISK
FILESYSTEM
KERNEL
MEMORY
NETWORK
NFS
PATROL
PRINTER
PROCESS
SECURITY
SMP
SWAP
USERS
LOG
Objects Table
bmc (1031)
patrolMIB (1)
patrolAgent (1)
patrolObjects (1)
objectsMask (1) r/w
patrolTraps (2)
objectsCwd (2) r/w
agentExecuteCommand (3)
objectsTable (3) na
patrolConsole (2)
objectsEntry (1) na
variablesTable (5)
objectName (1) r
applicationsTable (6)
objectDescr (3) r
applInstTable (7)
objectRowStatus (4) r/w
parametersTable (8)
30
© 1999 BMC SOFTWARE, INC. 3/17/99
Browsing PATROL namespace - 1
 Set objectCwd to the tree you want to inspect
 for example “/”
 Go to the desired “node”
 get the “objectsTable”, you see NT_CPU
 set objectCwd to “/CPU” … pick inst from objectsTable
 set objectCwd to “/CPU/CPU”… pick param from objectsTable
 set objectCwd to “/CPU/CPU/CPUCpuUtil”
 Read the wanted values
 get the “variablesTable” to find all the attributes
 Problem : No way to enforce a “session”, your set of
objectCwd might have been overwritten !
31
© 1999 BMC SOFTWARE, INC. 3/17/99
Execute PSL through SNMP
 Set
variable “agentExecuteCommand”
 Agent will execute immediately
 Fail/Success from return value of snmp_set()
32
© 1999 BMC SOFTWARE, INC. 3/17/99
Variables Table
bmc (1031)
patrolMIB (1)
patrolAgent (1)
patrolObjects (1)
objectsMask (1)
objectsCwd (2)
objectsTable (3)
variablesTable(5) na
patrolTraps (2)
VariablesEntry (1) na
variableName (2) r
agentExecuteCommand(3)
patrolConsole (2)
variableType (3) r
variableValue (4) r/w
variableDesr (5) r/w
variableRowStatus (6) r/w
33
© 1999 BMC SOFTWARE, INC. 3/17/99
Direct namespace access – Variables Table
 “Hooked”
on OID of :
.variablesTable.variableEntry.variableValue
 Need conversion of namespace variable


<length> = length of namespace variable
<conv> = ascii to value conversion of namespace variable
for example : /CPU = 47.67.80.85
 Simply
get : bmc.1.1.1.5.1.4.<len>.<conv>
 Result :



34
Fastest Namespace access
not useful for namespace “discovery”
Not “walk-able”
© 1999 BMC SOFTWARE, INC. 3/17/99
Applications Table
bmc (1031)
patrolMIB (1)
patrolAgent (1)
patrolObjects (1)
variablesTable(5)
applicationsTable(6) na
applicationsEntry(1) na
applicationName(1) r
patrolTraps (2)
applicationState (2) r
applWorstInst (3) r
agentExecuteCommand(3)
applMasterVersion(4) r
applMinorRevision (5) r
patrolConsole (2)
applicationRowStatus (6) r
applicationOid (7) na
35
© 1999 BMC SOFTWARE, INC. 3/17/99
Browsing PATROL namespace - 2
 Look
for the application in “applicationTable”
 Use that index to get the instances from the
application in “applInstTable”
 Use both indexes to get the parameters from the
“parametersTable”
 Get the required attribute from your parameter
 This method is “safe” but requires some
processing
36
© 1999 BMC SOFTWARE, INC. 3/17/99
Applications Example
applicationsTable
applicationsEntry (index)
applicationName
OS>%PSL print(snmp_walk("sess47", "1.3.6.1.4.1.1031.1.1.1.6.1.1")."\n");
0
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.1
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.2
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.3
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.4
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.5
2
11
9
10
3
4
20000207121727
20000207121727
20000207121727
20000207121727
20000207121727
20000207121727
1.3.6.1.4.1.1031.1.1.1.6.1.1.6
1.3.6.1.4.1.1031.1.1.1.6.1.1.7
1.3.6.1.4.1.1031.1.1.1.6.1.1.8
1.3.6.1.4.1.1031.1.1.1.6.1.1.9
1.3.6.1.4.1.1031.1.1.1.6.1.1.10
1.3.6.1.4.1.1031.1.1.1.6.1.1.11
10
6
6
7
3
6
20000207121727
20000207121727
20000207121727
20000207121727
20000207121727
20000207121727
20000207121727
1.3.6.1.4.1.1031.1.1.1.6.1.1.12
1.3.6.1.4.1.1031.1.1.1.6.1.1.13
1.3.6.1.4.1.1031.1.1.1.6.1.1.14
1.3.6.1.4.1.1031.1.1.1.6.1.1.15
1.3.6.1.4.1.1031.1.1.1.6.1.1.16
1.3.6.1.4.1.1031.1.1.1.6.1.1.17
1.3.6.1.4.1.1031.1.1.1.6.1.1.18
7
7
8
3
4
5
3
Application ID
String Length
Type
Application Name
37
© 1999 BMC SOFTWARE, INC. 3/17/99
string
string
string
HP
PATROLAGENT
SNMP_Test
string
string
string
COLLECTORS
CPU
DISK
string
string
string
string
string
string
string
string
string
string
string
string
string
FILESYSTEM
KERNEL
MEMORY
NETWORK
NFS
PATROL
PRINTER
PROCESS
SECURITY
SMP
SWAP
USERS
LOG
Instances Table
patrolObjects (1)
variablesTable(5)
applicationsTable(6)
applInstTable(7) na
applInstEntry (1) na
applInstName (1) r
applInstRuleState (2) r
applInstStatus (3) r
applInstWorstParam (4) r
applInstCreateIcon (5) r
applInstRowStatus (6) r
applInstOid (7) na
applInstPApplOid (8) r
applInstPInstOid (9) r
38
© 1999 BMC SOFTWARE, INC. 3/17/99
Instances Example
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.9
7
string
NETWORK
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.10
3
string
NFS
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.11
6
string
PATROL
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.12
7
string
PRINTER
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.13
7
string
PROCESS
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.14
8
string
SECURITY
applInstTable
applInstEntry (index)
applInstName
OS>%PSL print(snmp_walk("sess47", "1.3.6.1.4.1.1031.1.1.1.7.1.1.12")."\n");
20000207121828 1.3.6.1.4.1.1031.1.1.1.7.1.1.12.
816
1.3.6.1.4.1.1031.1.1.1.7.1.1.12.836
5
string
lj4mv
20000207121828
220000207121828 1.3.6.1.4.1.1031.1.1.1.7.1.1.12.844
20000207121828 1.3.6.1.4.1.1031.1.1.1.7.1.1.12.860
3
8
14
string
string
string
lp
sweetlip
Nutria_HPLaser
Application ID
Application Instance ID
Application Name
39
© 1999 BMC SOFTWARE, INC. 3/17/99
Parameters Table
parametersTable(8) na
parametersEntry (1) na
parameterName (1) r
parameterAutoScale (8) r
parameterState (2) r
parameterYaxisMin (9) r
parameterCurrentTime (3) r
parameterYaxisMax (10) r
parameterCurrentValue (4) r
parameterRowStatus (11) r/w
parameterPollingInt (5) r
parameterObjId (12) na
parameterRetries (6) r
parameterIntValue (13) r
parameterOutputMode (7) r
parameterActiveStat (14) r/w
parameterRunningStat (15) r/w
40
© 1999 BMC SOFTWARE, INC. 3/17/99
Parameters Example
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.11
6
string
PATROL
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.12
7
string
PRINTER
20000207121727 1.3.6.1.4.1.1031.1.1.1.6.1.1.13
7
string
PROCESS
OS>%PSL print(snmp_walk("sess47", "1.3.6.1.4.1.1031.1.1.1.7.1.1.12")."\n");
20000207121828 1.3.6.1.4.1.1031.1.1.1.7.1.1.12.816
5
string
20000207121828 1.3.6.1.4.1.1031.1.1.1.7.1.1.12.836
3
string
220000207121828 1.3.6.1.4.1.1031.1.1.1.7.1.1.12.844
8
string
20000207121828 1.3.6.1.4.1.1031.1.1.1.7.1.1.12.860
14
string
lj4mv
lp
sweetlip
Nutria_HPLaser
parametersTable
parametersEntry (index)
parameterName
applicationName
applInstName
OS>%PSL print(snmp_walk("sess47", "1.3.6.1.4.1.1031.1.1.1.8.1.1.12.816")."\n");
20000207121938 1.3.6.1.4.1.1031.1.1.1.8.1.1.
12.816.818
Application ID
Application Instance ID
Parameter ID
10
string
parameterIntValue
>%PSL print(snmp_walk("sess47", "1.3.6.1.4.1.1031.1.1.1.8.1.13.12.816")."\n");
20000207122103 1.3.6.1.4.1.1031.1.1.1.8.1.13.12.816.818
integer
0
41
© 1999 BMC SOFTWARE, INC. 3/17/99
PRNQLengthOS
Value
Trap Table
bmc (1031)
patrolMIB (1)
patrolAgent (1)
patrolObjects (1)
patrolTraps (2)
patrolTrapText (1) r
patrolTrapOrigin (2) r
patrolTrapExtra (3) r
piV1mTable (10) na
piV1mIp (10) na
piV1mPort (10) na
piV1mCommunity (10) na
piV1mRowStatus (10) r/w
agentExecuteCommand(3)
patrolConsole (2)
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© 1999 BMC SOFTWARE, INC. 3/17/99
Enterprise Traps
Standard Traps
patrolTraps (2)
patrolTrapWarmStart (1)
patrolTrapText (1)
patrolTrapOrigin (2)
patrolTrapExtra (3)
piV1mTable (10)
piV1mIp (10)
piV1mPort (10)
piV1mCommunity (10)
piV1mRowStatus (10)
Enterprise Traps (6) [1031.1.1.2]
patrolInformation (1)
VARIABLES {patrolTrapText, patrolTrapOrigin, patrolTrapExtra}
A patrolInformation trap is sent when a corresponding
event which may cause to that trap occurred.
patrolChangeStatus (2)
VARIABLES {patrolTrapText,patrolTrapOrigin,patrolTrapExtra}
A patrolChangeStatus is sent when a corresponding
event which may cause to that trap occurred.
patrolError (3)
VARIABLES {patrolTrapText,patrolTrapOrigin,patrolTrapExtra}
A patrolError is sent when a corresponding event
which may cause to that trap occurred.
patrolWarning (4)
VARIABLES {patrolTrapText,patrolTrapOrigin, patrolTrapExtra}
A patrolWarning is sent when a corresponding
event which may cause to that trap occurred.
patrolAlarm (5)
VARIABLES {patrolTrapText,patrolTrapOrigin, patrolTrapExtra}
A patrolAlarm is sent when a corresponding event
which may cause to that trap occurred.
patrolTrapV1Raised (10)
OBJECTS{patrolTrapText}
A patrolTrapV2Raised trap is sent when one of the PSL scripts
calls snmp_trap()function.
Traps are sent to SNMP V1
entity according to
piV1mTable.
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© 1999 BMC SOFTWARE, INC. 3/17/99
patrolTrapV1StateChanged (11)
OBJECTS{patrolTrapText}
A patrolTrapV1StateChanged is sent when Patrol Agent changes
state of one of the discovered application instances.
Trap Example
patrolAlarm (5)
========== SNMP Trap Received =============
From: 172.19.204.16 (1.3.6.1.4.1.1031.1.1.2) Enterprise Specific (5) Uptime: 0 day(s) 23:34:55 (8489554)
1.3.6.1.4.1.1031.1.1.2.1.0
84
string
Alarm #2 of global parameter 'NFSSNull' triggered on
'NFS.NFS'. 50 <= 100.00 <= 100
patrolTrapText
1.3.6.1.4.1.1031.1.1.2.2.0
17
string
/NFS/NFS/NFSSNull
1.3.6.1.4.1.1031.1.1.2.3.0
0
string
patrolTrapOrigin
========== End SNMP Trap Received =============
patrolTrapExtra
Source IP address
Enterprise Traps (6) [1031.1.1.2]
patrolChangeStatus (2)
========== SNMP Trap Received =============
From: 172.19.204.16 (1.3.6.1.4.1.1031.1.1.2) Enterprise Specific (2) Uptime: 0 day(s) 23:37:56 (8507631)
1.3.6.1.4.1.1031.1.1.2.1.0
99
string
Alert on 'NFS.NFS.NFSSNull' from global parameter
'NFSSNull' cancelled; exception no longer exists.
1.3.6.1.4.1.1031.1.1.2.2.0
17
string
/NFS/NFS/NFSSNull
1.3.6.1.4.1.1031.1.1.2.3.0
0
string
========== End SNMP Trap Received =============
patrolWarning (4)
========== SNMP Trap Received =============
From: 172.19.204.16 (1.3.6.1.4.1.1031.1.1.2) Enterprise Specific (4) Uptime: 0 day(s) 23:40:56 (8525616)
1.3.6.1.4.1.1031.1.1.2.1.0
85
string
Alarm #1 of global parameter 'NFSSReadDir' triggered on
'NFS.NFS'. 18 <= 19.19 <= 30
1.3.6.1.4.1.1031.1.1.2.2.0
20
string
/NFS/NFS/NFSSReadDir
1.3.6.1.4.1.1031.1.1.2.3.0
0
string
========== End SNMP Trap Received =============
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© 1999 BMC SOFTWARE, INC. 3/17/99
www.bmc.com
PSL SNMP Functions
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© 1999 BMC SOFTWARE, INC.
3/17/99
1st step : Starting SNMP subsystem
PATROL SNMP functionality can be stopped
 snmp_agent_start()

starts SNMP support
 snmp_agent_stop()

stops SNMP support
 snmp_agent_config()

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tells if SNMP support is active
© 1999 BMC SOFTWARE, INC. 3/17/99
PSL functions for SNMP managers
“All” SNMPv1 functions



snmp_(h_)get
snmp_(h_)get_next
snmp_(h_)set
 Plus
 snmp_walk
(just loop around get_next)
 No support for v2(c), v3 !!

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security, bulk get, new datatypes
© 1999 BMC SOFTWARE, INC. 3/17/99
Return format of snmp_functions
If type is
 String and first character printable

OID <tab> [strlen] <tab> “string” <tab> [actual string]
 String

OID <tab> [strlen] <tab> “string” <tab> [series of hex]
 gauge,

and first character non-printable
timeticks
OID <tab> [type] <tab> [value] <tab> “(“[hex-value]”)”
 integer,

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oid, ipAddress
OID <tab> [type] <tab> [value]
© 1999 BMC SOFTWARE, INC. 3/17/99
Receiving traps
 PSL functions



:
snmp_trap_ignore : close all listeners (close socket)
snmp_trap_listen : start listening for traps (open socket)
starts accumulating traps
snmp_trap_receive : process incoming traps (block/poll based)
only 1 per agent
 Functionality
is based on a “gentlemen's agreement”
Only one receiver for multiple KM’s
 Need for a “trap dispatcher” in PATROL ?
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© 1999 BMC SOFTWARE, INC. 3/17/99
Getting info from other SNMP Agents
What is an SNMP session in PATROL ?



snmp_open() : opens an SNMP session
snmp_close() : closes an SNMP session
snmp_config() : lists the SNMP sessions
 No
real session (like TCP session) because
SNMP = connectionless / stateless
 just a memory structure, so ...



50
Easier for the developer … open session once, reuse the
session with the session attributes !
Allows you to set timeouts/retries/port
Faster
© 1999 BMC SOFTWARE, INC. 3/17/99