The chapter Running the application describes how the application is configured and started. The topics include:
Refer also to the chapter(s)
The following two directories must exist in the system to run the agent:
the configuration directory stores all
configuration files used by the agent (refer to the chapter
The following directory must exist in the system to run the manager:
the configuration directory stores all
configuration files used by the manager (refer to the chapter
the database directory stores the internal database files.
The agent and manager uses (application) configuration parameters to find out where these directories are located. The parameters should be defined in an Erlang system configuration file. The following configuration parameters are defined for the SNMP application:
agent_options() = [agent_option()] agent_option() = {restart_type, restart_type()} | {agent_type, agent_type()} | {agent_verbosity, verbosity()} | {versions, versions()} | {discovery, agent_discovery()} | {priority, priority()} | {multi_threaded, multi_threaded()} | {db_dir, db_dir()} | {db_init_error, db_init_error()} | {local_db, local_db()} | {net_if, agent_net_if()} | {mibs, mibs()} | {mib_storage, mib_storage()} | {mib_server, mib_server()} | {audit_trail_log, audit_trail_log()} | {error_report_mod, error_report_mod()} | {note_store, note_store()} | {symbolic_store, symbolic_store()} | {target_cache, target_cache()} | {config, agent_config()} manager_options() = [manager_option()] manager_option() = {restart_type, restart_type()} | {net_if, manager_net_if()} | {server, server()} | {note_store, note_store()} | {config, manager_config()} | {inform_request_behaviour, manager_irb()} | {mibs, manager_mibs()} | {priority, priority()} | {audit_trail_log, audit_trail_log()} | {versions, versions()} | {def_user_mod, def_user_module() | {def_user_data, def_user_data()}
Agent specific config options and types:
If
Default is
The
The
For defaults see the options in
These are options effecting discovery
The default values for the
These are options effecting discovery
The default values for the
If
Default is
Defines where the SNMP agent internal db files are stored.
Defines options specific for the SNMP agent local database.
For defaults see the options in
When starting snmpa_local_db it always tries to open an
existing database. If
Default is
The auto save interval. The table is flushed to disk whenever not accessed for this amount of time.
Default is
Defines options specific for the SNMP agent network interface entity.
For defaults see the options in
Module which handles the network interface part for the
SNMP agent. Must implement the
Default is
These options are actually specific to the used module.
The ones shown here are applicable to the default
For defaults see the options in
These options are actually specific to the used module.
The ones shown here are applicable to the default
For defaults see the options in
Module which handles the network interface filter part for the
SNMP agent. Must implement the
Default is
Max number of simultaneous requests handled by the agent.
Default is
Specifies a list of MIBs (including path) that defines which MIBs are initially loaded into the SNMP master agent.
Note that the following will always be loaded:
Default is
Specifies how info retrieved from the mibs will be stored.
If
If
If
Default is
Defines options specific for the SNMP agent mib server.
For defaults see the options in
If this value is false, then when loading a mib each mib- entry is checked prior to installation of the mib. The purpose of the check is to prevent that the same symbolic mibentry name is used for different oid's.
Default is
If this value is false, then when loading a mib each trap is checked prior to installation of the mib. The purpose of the check is to prevent that the same symbolic trap name is used for different trap's.
Default is
Shall the agent utilize the mib server lookup cache or not.
Default is
Defines options specific for the SNMP agent mib server cache.
For defaults see the options in
Defines if the mib server shall perform cache gc automatically or
leave it to the user (see
Default is
Defines how old the entries in the cache will be allowed before they are GC'ed (assuming GC is performed). Each entry in the cache is "touched" whenever it is accessed.
The age is defined in milliseconds.
Default is
When performing a GC, this is the max number of cache entries that will be deleted from the cache.
The reason for having this limit is that if the cache is large, the GC can potentially take a long time, during which the agent is locked.
Default is
Defines an error report module, implementing the
Default is
Defines options specific for the SNMP agent symbolic store.
For defaults see the options in
Defines options specific for the SNMP agent target cache.
For defaults see the options in
Defines specific config related options for the SNMP agent.
For defaults see the options in
Defines where the SNMP agent configuration files are stored.
If
Default is
Manager specific config options and types:
Specifies the options for the manager server process.
Default is
Asynchroneous request cleanup time. For every requests,
some info is stored internally, in order to be able to
deliver the reply (when it arrives) to the proper destination.
If the reply arrives, this info will be deleted. But if
there is no reply (in time), the info has to be deleted
after the best before time has been passed.
This cleanup will be performed at regular intervals, defined
by the
Time in milli-seconds.
Default is
Defines specific config related options for the SNMP manager.
For defaults see the options in
Defines where the SNMP manager configuration files are stored.
Defines where the SNMP manager store persistent data.
Defines the repair option for the persistent database (if and how the table is repaired when opened).
Default is
The auto save interval. The table is flushed to disk whenever not accessed for this amount of time.
Default is
This option defines how the manager will handle the sending of response (acknowledgment) to received inform-requests.
See
Default is
Specifies a list of MIBs (including path) and defines which MIBs are initially loaded into the SNMP manager.
Default is
Defines options specific for the SNMP manager network interface entity.
For defaults see the options in
These options are actually specific to the used module.
The ones shown here are applicable to the default
For defaults see the options in
Module which handles the network interface part for the
SNMP manager. Must implement the
Default is
These options are actually specific to the used module.
The ones shown here are applicable to the default
For defaults see the options in
Module which handles the network interface filter part for the
SNMP manager. Must implement the
Default is
The module implementing the default user. See the
Default is
Data for the default user. Passed to the user when calling the callback functions.
Default is
Common config types:
See
Default is
Defines what to do if the agent is unable to open an
existing database file.
Default is
Defines the Erlang priority for all SNMP processes.
Default is
Which SNMP versions shall be accepted/used.
Default is
Verbosity for a SNMP process. This specifies now much debug info is printed.
Default is
If
Default is
If
Default is
Receive buffer size.
Default value is defined by
Send buffer size.
Default value is defined by
Specifies the options for the SNMP note store.
For defaults see the options in
Note cleanup time. When storing a note in the note store,
each note is given lifetime. Every
Default is
If present, this option specifies the options for the
audit trail logging. The
If not present, audit trail logging is not used.
Specifies what type of an audit trail log should be used. The effect of the type is actually different for the the agent and the manager.
For the agent:
For the manager:
Default is
Specifies where the audit trail log should be stored.
If
Specifies the size of the audit
trail log. This parameter is sent to
If
Specifies if and how the audit trail log shall be repaired
when opened. Unless this parameter has the value
Default is
Specifies if the audit trail log entries will be (sequence) numbered or not. The range of the sequence numbers are according to RFC 5424, i.e. 1 through 2147483647.
Default is
To to start the application (agent and/or manager), the configuration files must be modified and there are two ways of doing this. Either edit the files manually, or run the configuration tool as follows.
If authentication or encryption is used (SNMPv3 only), start
the
1> snmp:config(). Simple SNMP configuration tool (version 4.0) ------------------------------------------------ Note: Non-trivial configurations still has to be done manually. IP addresses may be entered as dront.ericsson.se (UNIX only) or 123.12.13.23 ------------------------------------------------ Configure an agent (y/n)? [y] Agent system config: -------------------- 1. Agent process priority (low/normal/high) [normal] 2. What SNMP version(s) should be used (1,2,3,1&2,1&2&3,2&3)? [3] 1&2&3 3. Configuration directory (absolute path)? [/ldisk/snmp] /ldisk/snmp/agent/conf 4. Config verbosity (silence/info/log/debug/trace)? [silence] 5. Database directory (absolute path)? [/ldisk/snmp] /ldisk/snmp/agent/db 6. Mib storage type (ets/dets/mnesia)? [ets] 7. Target cache verbosity (silence/info/log/debug/trace)? [silence] 8. Symbolic store verbosity (silence/info/log/debug/trace)? [silence] 9. Local DB verbosity (silence/info/log/debug/trace)? [silence] 10. Local DB repair (true/false/force)? [true] 11. Local DB auto save (infinity/milli seconds)? [5000] 12. Error report module? [snmpa_error_logger] 13. Agent type (master/sub)? [master] 14. Master-agent verbosity (silence/info/log/debug/trace)? [silence] log 15. Shall the agent re-read the configuration files during startup (and ignore the configuration database) (true/false)? [true] 16. Multi threaded agent (true/false)? [false] true 17. Check for duplicate mib entries when installing a mib (true/false)? [false] 18. Check for duplicate trap names when installing a mib (true/false)? [false] 19. Mib server verbosity (silence/info/log/debug/trace)? [silence] 20. Mib server cache (true/false)? [true] 21. Note store verbosity (silence/info/log/debug/trace)? [silence] 22. Note store GC timeout? [30000] 23. Shall the agent use an audit trail log (y/n)? [n] y 23b. Audit trail log type (write/read_write)? [read_write] 23c. Where to store the audit trail log? [/ldisk/snmp] /ldisk/snmp/agent/log 23d. Max number of files? [10] 23e. Max size (in bytes) of each file? [10240] 23f. Audit trail log repair (true/false/truncate)? [true] 24. Which network interface module shall be used? [snmpa_net_if] 25. Network interface verbosity (silence/info/log/debug/trace)? [silence] log 25a. Bind the agent IP address (true/false)? [false] 25b. Shall the agents IP address and port be not reusable (true/false)? [false] 25c. Agent request limit (used for flow control) (infinity/pos integer)? [infinity] 32 25d. Receive buffer size of the agent (in bytes) (default/pos integer)? [default] 25e. Send buffer size of the agent (in bytes) (default/pos integer)? [default] 25f. Do you wish to specify a network interface filter module (or use default) [default] Agent snmp config: ------------------ 1. System name (sysName standard variable) [bmk's agent] 2. Engine ID (snmpEngineID standard variable) [bmk's engine] 3. Max message size? [484] 4. The UDP port the agent listens to. (standard 161) [4000] 5. IP address for the agent (only used as id when sending traps) [127.0.0.1] 6. IP address for the manager (only this manager will have access to the agent, traps are sent to this one) [127.0.0.1] 7. To what UDP port at the manager should traps be sent (standard 162)? [5000] 8. Do you want a none- minimum- or semi-secure configuration? Note that if you chose v1 or v2, you won't get any security for these requests (none, minimum, semi_des, semi_aes) [minimum] making sure crypto server is started... 8b. Give a password of at least length 8. It is used to generate private keys for the configuration: kalle-anka 9. Current configuration files will now be overwritten. Ok (y/n)? [y] - - - - - - - - - - - - - Info: 1. SecurityName "initial" has noAuthNoPriv read access and authenticated write access to the "restricted" subtree. 2. SecurityName "all-rights" has noAuthNoPriv read/write access to the "internet" subtree. 3. Standard traps are sent to the manager. 4. Community "public" is mapped to security name "initial". 5. Community "all-rights" is mapped to security name "all-rights". The following agent files were written: agent.conf, community.conf, standard.conf, target_addr.conf, target_params.conf, notify.conf, vacm.conf and usm.conf - - - - - - - - - - - - - Configure a manager (y/n)? [y] Manager system config: ---------------------- 1. Manager process priority (low/normal/high) [normal] 2. What SNMP version(s) should be used (1,2,3,1&2,1&2&3,2&3)? [3] 1&2&3 3. Configuration directory (absolute path)? [/ldisk/snmp] /ldisk/snmp/manager/conf 4. Config verbosity (silence/info/log/debug/trace)? [silence] log 5. Database directory (absolute path)? [/ldisk/snmp] /ldisk/snmp/manager/db 6. Database repair (true/false/force)? [true] 7. Database auto save (infinity/milli seconds)? [5000] 8. Inform request behaviour (auto/user)? [auto] 9. Server verbosity (silence/info/log/debug/trace)? [silence] log 10. Server GC timeout? [30000] 11. Note store verbosity (silence/info/log/debug/trace)? [silence] 12. Note store GC timeout? [30000] 13. Which network interface module shall be used? [snmpm_net_if] 14. Network interface verbosity (silence/info/log/debug/trace)? [silence] log 15. Bind the manager IP address (true/false)? [false] 16. Shall the manager IP address and port be not reusable (true/false)? [false] 17. Receive buffer size of the manager (in bytes) (default/pos integer)? [default] 18. Send buffer size of the manager (in bytes) (default/pos integer)? [default] 19. Shall the manager use an audit trail log (y/n)? [n] y 19b. Where to store the audit trail log? [/ldisk/snmp] /ldisk/snmp/manager/log 19c. Max number of files? [10] 19d. Max size (in bytes) of each file? [10240] 19e. Audit trail log repair (true/false/truncate)? [true] 20. Do you wish to assign a default user [yes] or use the default settings [no] (y/n)? [n] Manager snmp config: -------------------- 1. Engine ID (snmpEngineID standard variable) [bmk's engine] 2. Max message size? [484] 3. IP address for the manager (only used as id when sending requests) [127.0.0.1] 4. Port number (standard 162)? [5000] 5. Configure a user of this manager (y/n)? [y] 5b. User id? kalle 5c. User callback module? snmpm_user_default 5d. User (callback) data? [undefined] 5. Configure a user of this manager (y/n)? [y] n 6. Configure an agent handled by this manager (y/n)? [y] 6b. User id? kalle 6c. Target name? [bmk's agent] 6d. Version (1/2/3)? [1] 3 6e. Community string ? [public] 6f. Engine ID (snmpEngineID standard variable) [bmk's engine] 6g. IP address for the agent [127.0.0.1] 6h. The UDP port the agent listens to. (standard 161) [4000] 6i. Retransmission timeout (infinity/pos integer)? [infinity] 6j. Max message size? [484] 6k. Security model (any/v1/v2c/usm)? [any] usm 6l. Security name? ["initial"] 6m. Security level (noAuthNoPriv/authNoPriv/authPriv)? [noAuthNoPriv] authPriv 6. Configure an agent handled by this manager (y/n)? [y] n 7. Configure an usm user handled by this manager (y/n)? [y] 7a. Engine ID [bmk's engine] 7b. User name? hobbes 7c. Security name? [hobbes] 7d. Authentication protocol (no/sha/md5)? [no] sha 7e Authentication [sha] key (length 0 or 20)? [""] [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20] 7d. Priv protocol (no/des/aes)? [no] des 7f Priv [des] key (length 0 or 16)? [""] 10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25 7. Configure an usm user handled by this manager (y/n)? [y] n 8. Current configuration files will now be overwritten. Ok (y/n)? [y] - - - - - - - - - - - - - The following manager files were written: manager.conf, agents.conf , users.conf and usm.conf - - - - - - - - - - - - - -------------------- Configuration directory for system file (absolute path)? [/ldisk/snmp] ok
Start Erlang with the command:
erl -config /tmp/snmp/sys
If authentication or encryption is used (SNMPv3 only), start
the
1> application:start(crypto). ok
2> application:start(snmp). ok
It is possible to debug every (non-supervisor) process of the
application (both agent and manager), possibly with the exception
of the net_if module(s), which could be supplied by a user of the
application). This is done by calling the
3> snmpa:verbosity(master_agent, log). ok 5> snmpa:verbosity(net_if, log). ok 6> %% Example of output from the agent when a get-next-request arrives: ** SNMP NET-IF LOG: got packet from {147,12,12,12}:5000 ** SNMP NET-IF MPD LOG: v1, community: all-rights ** SNMP NET-IF LOG: got pdu from {147,12,12,12}:5000 {pdu, 'get-next-request', 62612569,noError,0, [{varbind,[1,1],'NULL','NULL',1}]} ** SNMP MASTER-AGENT LOG: apply: snmp_generic,variable_func,[get,{sysDescr,persistent}] ** SNMP MASTER-AGENT LOG: returned: {value,"Erlang SNMP agent"} ** SNMP NET-IF LOG: reply pdu: {pdu,'get-response',62612569,noError,0, [{varbind,[1,3,6,1,2,1,1,1,0], 'OCTET STRING', "Erlang SNMP agent",1}]} ** SNMP NET-IF INFO: time in agent: 19711 mysec
Other useful function(s) for debugging the agent are:
For example, this function can show the counters
Another usefull way to debug the agent is to pretty-print the content of some of the (MIB-) tables handled directly by the agent. This can be done for the following tables: