snmpwalk

(PHP 4, PHP 5)

snmpwalk — 从代理返回所有的 SNMP 对象

说明

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

返回由 object_id 作为根的 SNMP 对象值所组成的数组，错误则返回 FALSE 。

snmpwalk() 函数是用来读取所有由 hostname 指定的 SNMP 代理的值。Community 指定该代理中具有读权限的域。一个为 NULL 的 object_id 将被看作 SNMP 对象树的根，而在此树下的所有对象将作为一个数组被返回。如果指定了 object_id，则返回所有在 object_id 下的 SNMP 对象。

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

上边的函数调用将从运行于本机的 SNMP 代理那里返回所有的 SNMP 对象。可使用循环遍历这些值。

  <?php
 foreach ( $a  as  $val ) {
    echo  " $val \n" ;
}
 ?>

用户评论:

[#1] http://mike.eire.ca [2005-03-23 10:54:45]

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); ?>

[#2] bobby [dot] clark [at] eku [dot] edu [2003-09-17 14:29:02]

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); ?>

[#3] Lars Troen [2003-03-14 03:18:46]

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.

[#4] anders at ei dot nu [2003-01-29 10:11:47]

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;

[#5] steve at ourabode dot org [2002-03-26 03:54:30]

Timeout is in MICRO seconds.
1,000,000 &micros = 1 s

[#6] layer2 at www dot com [2001-08-29 08:52:21]

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.

[#7] john at antefacto dot com [2001-08-17 08:21:05]

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.

[#8] billf at freebsd dot org [2001-08-01 02:22:21]

for the poster wondering what the
timeout field was measured in:

from the ucd-snmp header file snmp_api.h:

long timeout;

[#9] jmartinson(AT_nospam)info234.com [2001-06-20 07:41:26]

A quick router device view:

<?php 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>"; ?>