(PHP 4, PHP 5, PHP 7)

snmpwalkFetch all the SNMP objects from an agent


array snmpwalk ( string $hostname , string $community , string $object_id [, int $timeout = 1000000 [, int $retries = 5 ]] )

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

Список параметров


The SNMP agent (server).


The read community.


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.


The number of microseconds until the first timeout.


The number of times to retry if timeouts occur.

Возвращаемые значения

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


Пример #1 snmpwalk() Example


foreach (
$a as $val) {


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

Смотрите также

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

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User Contributed Notes 9 notes

steve at ourabode dot org
16 years ago
Timeout is in MICRO seconds.
1,000,000 &micros = 1 s
Lars Troen
15 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.
anders at ei dot nu
15 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..


session.version = SNMP_VERSION_1;

session.version = SNMP_VERSION_2c;
layer2 at www dot com
16 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 . 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.
john at antefacto dot com
16 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.
billf at freebsd dot org
16 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 */
17 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>$sysDescr</td></tr></table><br>";
print "<table border=1 bgcolor=#ffffff>";
print "<tr>
for ($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>";

bobby [dot] clark [at] eku [dot] edu
14 years ago
I had to use an object_id like these.

= '';
$community = 'public';
$object_id = 'IF-MIB::interfaces.ifTables.ifEntry.ifAdminStatus';

$sysdesc = snmpwalk($host, $community', $object_id);
13 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:

= snmpwalk("", "public", null);
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