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 __construct(
    int $version,
    string $hostname,
    string $community,
    int $timeout = -1,
    int $retries = -1
)
public close(): bool
public get(array|string $objectId, bool $preserveKeys = false): mixed
public getErrno(): int
public getError(): string
public getnext(array|string $objectId): mixed
public set(array|string $objectId, array|string $type, array|string $value): bool
public setSecurity(
    string $securityLevel,
    string $authProtocol = "",
    string $authPassphrase = "",
    string $privacyProtocol = "",
    string $privacyPassphrase = "",
    string $contextName = "",
    string $contextEngineId = ""
): bool
public 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_LIBRARYThe return values will be as returned by the Net-SNMP library.
SNMP_VALUE_PLAINThe 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_MODULEDISMAN-EVENT-MIB::sysUpTimeInstance
SNMP_OID_OUTPUT_SUFFIXsysUpTimeInstance
SNMP_OID_OUTPUT_UCDsystem.sysUpTime.sysUpTimeInstance
SNMP_OID_OUTPUT_NONEUndefined
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.

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