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    snmpwalk

    (PHP 4, PHP 5, PHP 7, PHP 8)

    snmpwalk — Fetch all the SNMP objects from an agent

    Description

    snmpwalk(
        string $hostname,
        string $community,
        array|string $object_id,
        int $timeout = -1,
        int $retries = -1
    ): array|false

    snmpwalk() function is used to read all the values from an SNMP agent specified by the hostname.

    Parameters

    hostname

    The SNMP agent (server).

    community

    The read community.

    object_id

    If null, object_id is taken as the root of the SNMP objects tree and all objects under that tree are returned as an array.

    If object_id is specified, all the SNMP objects below that object_id are returned.

    timeout

    The number of microseconds until the first timeout.

    retries

    The number of times to retry if timeouts occur.

    Return Values

    Returns an array of SNMP object values starting from the object_id as root or false on error.

    Examples

    Example #1 snmpwalk() Example

    <?php
    $a     = snmpwalk("127.0.0.1", "public", "");

    foreach (    $a as $val) {
    echo     "$val\n";
    }

    ?>

    Above function call would return all the SNMP objects from the SNMP agent running on localhost. One can step through the values with a loop

    See Also

    • snmprealwalk() - Return all objects including their respective object ID within the specified one

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    User Contributed Notes 9 notes

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    3
    Lars Troen
    21 years ago
    Note that there's different behaviuor in php snmpwalk and ucd snmpwalk. If you try to walk an oid that has one value not under a subkey of the walked oid, ucd snmpwalk will return the value while php's snmpwalk will not.
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    1
    anders at ei dot nu
    21 years ago
    It would be nice to be able to specify what snmp version to use ( 1,2c,3 )

    For now, I'ts hardcoded in ext/snmp/snmp.c

    change session.version from 1 to 2c or 3 if you need for now..

    i.e

    session.version = SNMP_VERSION_1;

    to:
    session.version = SNMP_VERSION_2c;
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    0
    http://mike.eire.ca
    19 years ago
    I found on Windows (PHP 5) an empty string did not return anything, it just timed out.  I had to use null instead:

    <?php
    $a     = snmpwalk("127.0.0.1", "public", null);
    ?>
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    0
    steve at ourabode dot org
    22 years ago
    Timeout is in MICRO seconds.
    1,000,000 &micros = 1 s
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    0
    layer2 at www dot com
    23 years ago
    Something to care about in dealing with snmpwalk:<BR>
    While walking the MIB, snmpwalk puts info that gets into an array, and that is correct.<BR>
    The trouble happened when snmpwalk needs to collect information from instances that contains subinstances (i.e. walking .1.2.3.4.5 and having instances like 1.1, 1.2, 1.3): in this case it gets info and passes into an array, but when walking the array, each value is preceeded by 'Counter32: '.<BR>
    I've tested this in many ways and it always happened the same way.
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    0
    john at antefacto dot com
    23 years ago
    Ah. That's why all of our SNMP stuff was timing out anytime there was any load on the system. Sigh. A waste of two weeks trying to debug snmp....

    Even the snmpcmd manpage doesn't give a
    unit for timeout.
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    0
    billf at freebsd dot org
    23 years ago
    for the poster wondering what the
    timeout field was measured in:

    from the ucd-snmp header file snmp_api.h:

        long    timeout;
        /* Number of uS until first timeout
        then exponential backoff */
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    0
    jmartinson(AT_nospam)info234.com
    23 years ago
    A quick router device view:

    <?
    include "header.html";

    $host = "auscr1";
    $community = "tellme";
                        
    $sysDescr = snmpget("$host","$community","system.sysDescr.0");
    $ifDescr = snmpwalk("$host","$community","interfaces.ifTable.ifEntry.ifDescr");
    $ifIndex = snmpwalk("$host","$community","interfaces.ifTable.ifEntry.ifIndex");
    $ifAdminStatus = snmpwalk("$host","$community","interfaces.ifTable.ifEntry.ifAdminStatus");
    $ifOperStatus = snmpwalk("$host","$community","interfaces.ifTable.ifEntry.ifOperStatus");
    $ifLastChange = snmpwalk("$host","$community","interfaces.ifTable.ifEntry.ifLastChange");
                                             
    print     "<table border=1 bgcolor=#ffffff><tr><td>$host</td></tr></table><br>";
    print     "<table border=1 bgcolor=#ffffff><tr><td>$sysDescr</td></tr></table><br>";
    print     "<table border=1 bgcolor=#ffffff>";
    print     "<tr>
            <td>ifIndex</td>
            <td>ifDescr</td>
            <td>ifAdminStatus</td>
            <td>ifOperStatus</td>
            <td>ifLastChange</td>
            </tr>"    ;
                
    for (    $i=0; $i<count($ifIndex); $i++) {
            print     "<tr>";
            print     "<td>$ifIndex[$i]</td>";
            print     "<td>$ifDescr[$i]</td>";
            print     "<td>$ifAdminStatus[$i]</td>";
            print     "<td>$ifOperStatus[$i]</td>";
            print     "<td>$ifLastChange[$i]</td>";
            print     "</tr>";
    }           
    print     "</table>";

    ?>
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    -1
    bobby [dot] clark [at] eku [dot] edu
    21 years ago
    I had to use an object_id like these.
    'SNMPv2-MIB::system.sysDescr.0'
    'IF-MIB::interfaces.ifTable.ifEntry.ifAdminStatus'

    <?php
    $host     = '192.168.1.1';
    $community = 'public';
    $object_id = 'IF-MIB::interfaces.ifTables.ifEntry.ifAdminStatus';

    $sysdesc = snmpwalk($host, $community', $object_id);
    print_r($sysdesc);
    ?>
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