The SNMP class

(PHP 5 >= 5.4.0, PHP 7, PHP 8)

Introduction

Represents SNMP session.

Class synopsis

class SNMP {

/* Constants */

public const int VERSION_1;

public const int VERSION_2c;

public const int VERSION_2C;

public const int VERSION_3;

public const int ERRNO_NOERROR;

public const int ERRNO_ANY;

public const int ERRNO_GENERIC;

public const int ERRNO_TIMEOUT;

public const int ERRNO_ERROR_IN_REPLY;

public const int ERRNO_OID_NOT_INCREASING;

public const int ERRNO_OID_PARSING_ERROR;

public const int ERRNO_MULTIPLE_SET_QUERIES;

/* Properties */

public readonly array $info;

public ?int $max_oids;

public int $valueretrieval;

public bool $quick_print;

public bool $enum_print;

public int $oid_output_format;

public bool $oid_increasing_check;

public int $exceptions_enabled;

/* Methods */

public function __construct(
    int $version,
    string $hostname,
    string $community,
    int $timeout = -1,
    int $retries = -1
)

public function close(): bool

public function get(array|string $objectId, bool $preserveKeys = false): mixed

public function getErrno(): int

public function getError(): string

public function getnext(array|string $objectId): mixed

public function set(array|string $objectId, array|string $type, array|string $value): bool

public function setSecurity(
    string $securityLevel,
    string $authProtocol = "",
    string $authPassphrase = "",
    string $privacyProtocol = "",
    string $privacyPassphrase = "",
    string $contextName = "",
    string $contextEngineId = ""
): bool

public function walk(
    array|string $objectId,
    bool $suffixAsKey = false,
    int $maxRepetitions = -1,
    int $nonRepeaters = -1
): array|false

}

Properties

max_oids

Maximum OID per GET/SET/GETBULK request

valueretrieval

Controls the method how the SNMP values will be returned

`SNMP_VALUE_LIBRARY`	The return values will be as returned by the Net-SNMP library.
`SNMP_VALUE_PLAIN`	The return values will be the plain value without the SNMP type information.
`SNMP_VALUE_OBJECT`	The return values will be objects with the properties "value" and "type", where the latter is one of the SNMP_OCTET_STR, SNMP_COUNTER etc. constants. The way "value" is returned is based on which one of `SNMP_VALUE_LIBRARY`, `SNMP_VALUE_PLAIN` is set

quick_print

Value of quick_print within the NET-SNMP library

Sets the value of quick_print within the NET-SNMP library. When this is set (1), the SNMP library will return 'quick printed' values. This means that just the value will be printed. When quick_print is not enabled (default) the NET-SNMP library prints extra information including the type of the value (i.e. IpAddress or OID). Additionally, if quick_print is not enabled, the library prints additional hex values for all strings of three characters or less.

enum_print

Controls the way enum values are printed

Parameter toggles if walk/get etc. should automatically lookup enum values in the MIB and return them together with their human readable string.

oid_output_format

Controls OID output format

**OID .1.3.6.1.2.1.1.3.0 representation for various `oid_output_format` values**
`SNMP_OID_OUTPUT_FULL`	.iso.org.dod.internet.mgmt.mib-2.system.sysUpTime.sysUpTimeInstance
`SNMP_OID_OUTPUT_NUMERIC`	.1.3.6.1.2.1.1.3.0
`SNMP_OID_OUTPUT_MODULE`	DISMAN-EVENT-MIB::sysUpTimeInstance
`SNMP_OID_OUTPUT_SUFFIX`	sysUpTimeInstance
`SNMP_OID_OUTPUT_UCD`	system.sysUpTime.sysUpTimeInstance
`SNMP_OID_OUTPUT_NONE`	Undefined

oid_increasing_check

Controls disabling check for increasing OID while walking OID tree

Some SNMP agents are known for returning OIDs out of order but can complete the walk anyway. Other agents return OIDs that are out of order and can cause SNMP::walk() to loop indefinitely until memory limit will be reached. PHP SNMP library by default performs OID increasing check and stops walking on OID tree when it detects possible loop with issuing warning about non-increasing OID faced. Set oid_increasing_check to false to disable this check.

exceptions_enabled

Controls which failures will raise SNMPException instead of warning. Use bitwise OR'ed SNMP::ERRNO_* constants. By default all SNMP exceptions are disabled.

info

Read-only property with remote agent configuration: hostname, port, default timeout, default retries count

Predefined Constants

SNMP Error Types

SNMP::ERRNO_NOERROR: No SNMP-specific error occurred.
SNMP::ERRNO_GENERIC: A generic SNMP error occurred.
SNMP::ERRNO_TIMEOUT: Request to SNMP agent timed out.
SNMP::ERRNO_ERROR_IN_REPLY: SNMP agent returned an error in reply.
SNMP::ERRNO_OID_NOT_INCREASING: SNMP agent faced OID cycling reporning non-increasing OID while executing (BULK)WALK command. This indicates bogus remote SNMP agent.
SNMP::ERRNO_OID_PARSING_ERROR: Library failed while parsing OID (and/or type for SET command). No queries has been made.
SNMP::ERRNO_MULTIPLE_SET_QUERIES: Library will use multiple queries for SET operation requested. That means that operation will be performed in a non-transaction manner and second or subsequent chunks may fail if a type or value failure will be faced.
SNMP::ERRNO_ANY: All SNMP::ERRNO_* codes bitwise OR'ed.

SNMP Protocol Versions

SNMP::VERSION_1
SNMP::VERSION_2C, SNMP::VERSION_2c
SNMP::VERSION_3

SNMP::close — Close SNMP session
SNMP::__construct — Creates SNMP instance representing session to remote SNMP agent
SNMP::get — Fetch an SNMP object
SNMP::getErrno — Get last error code
SNMP::getError — Get last error message
SNMP::getnext — Fetch an SNMP object which follows the given object id
SNMP::set — Set the value of an SNMP object
SNMP::setSecurity — Configures security-related SNMPv3 session parameters
SNMP::walk — Fetch SNMP object subtree