snmpwalk

描述

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
for ($i=0; $i < count($a); $i++) {
    echo $a[$i];
}
?>

add a note User Contributed Notes

http://mike.eire.ca
24-Mar-2005 02:54


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);

?>

bobby [dot] clark [at] eku [dot] edu
18-Sep-2003 05:29


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);

?>

Lars Troen
14-Mar-2003 07:18


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
30-Jan-2003 02:11


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;

steve at ourabode dot org
26-Mar-2002 07:54


Timeout is in MICRO seconds.

1,000,000 &micros = 1 s

layer2 at www dot com
29-Aug-2001 11:52


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.

john at antefacto dot com
17-Aug-2001 11:21


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
01-Aug-2001 05:22


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 */

jmartinson(AT_nospam)info234.com
20-Jun-2001 10:41


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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