snmpget

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

snmpget — 获取一个 SNMP 对象

说明

snmpget ( string $hostname , string $community , string $object_id , int $timeout = ? , int $retries = ? ) : string

成功则返回 SNMP 的对象值，失败则返回 false。

函数 snmpget() 用于读取由 object_id 指定的 SNMP 对象值。hostname 指定 SNMP 代理，而 community 参数指定具有读权限的域的名字。


<?php
$syscontact = snmpget("127.0.0.1", "public", "system.SysContact.0");
?>

User Contributed Notes

maxie_ro at do dot not dot spam dot yahoo dot com 25-Jun-2009 06:23


This function can be used to identify devices on a network, by getting their sysObjectID and sysDescr. On short, this is what I did:

<?php

   $sysid = @snmpget($ip, 'public', '.1.3.6.1.2.1.1.2.0', 300);

   if($sysid) {

      $sysdescr = @snmpget($ip, 'public', '.1.3.6.1.2.1.1.1.0', 300);

   }

?>



What I get for equipments, for example:

<?php

   $sysid = 'OID: .iso.3.6.1.4.1.5003.8.1.1.57';// => AudioCodes MP114;

   //.iso.3.6.1.4.1. is a "prefix" for the OID domain

   //5003 is the IANA number for AudioCodes

   //8.1.1.57 identifies the equipment type (MP-114)

   $sysdescr = '"Product: MP-114 FXS;SW Version: 5.00A.024"';

?>

Unfortunately, not all of them report correct objectID, for example they report only the vendor and stop there etc.



In case you are wondering why I used the code '.1.3.6.1.2.1.1.2.0' in the function call instead of "sysObjectID.0", it's because only numeric codes seem to work on Windows. For more codes, google "cisco SNMP Object Navigator".

Have fun.

d dot shereck at gmail dot com 19-Nov-2008 03:24


For those wishing to use v2 or 3



you can consult the php_snmp.h header

here is the list of functions



PHP_FUNCTION(snmpget);

PHP_FUNCTION(snmpgetnext);

PHP_FUNCTION(snmpwalk);

PHP_FUNCTION(snmprealwalk);

PHP_FUNCTION(snmp_get_quick_print);

PHP_FUNCTION(snmp_set_quick_print);

PHP_FUNCTION(snmp_set_enum_print);

PHP_FUNCTION(snmp_set_oid_output_format);

PHP_FUNCTION(snmpset);



PHP_FUNCTION(snmp2_get);

PHP_FUNCTION(snmp2_getnext);

PHP_FUNCTION(snmp2_walk);

PHP_FUNCTION(snmp2_real_walk);

PHP_FUNCTION(snmp2_set);



PHP_FUNCTION(snmp3_get);

PHP_FUNCTION(snmp3_getnext);

PHP_FUNCTION(snmp3_walk);

PHP_FUNCTION(snmp3_real_walk);

PHP_FUNCTION(snmp3_set);



PHP_FUNCTION(snmp_set_valueretrieval);

PHP_FUNCTION(snmp_get_valueretrieval);

ac221 at sussex dot ac dot uk 24-Nov-2007 01:49


Some SNMP agents return mac addresses as hex encoded ascii.



e.g. '30:30:3a:31:37:3a:66:32:3a:39:62:3a:34:36:3a:30:65'



Each octet represents 4 bits of the mac address.

Some vendors may also encode the separators into the string.



Heres a function to convert these strings back into plain hex.



<?php

$hexStr = '30:30:3a:31:37:3a:66:32:3a:39:62:3a:34:36:3a:30:65';



echo(str_replace(':','',hexStr2Ascii($hexStr)));



function hexStr2Ascii($hexStr,$separator = ':'){

    $hexStrArr = explode($separator,$hexStr);

    $asciiOut = null;

    foreach($hexStrArr as $octet){

        $asciiOut .= chr(hexdec($octet));

    }

    return $asciiOut;

}

?>



Outputs: '0017f29b460e'

brunoseys at telenet dot be 02-Oct-2007 04:22


According the SNMPv2-MIB DEFINITIONS the right syntax should be "system.sysContact.0" and NOT "system.SysContact.0" as used in the above example 2251. 



SNMPv2-MIB DEFINITIONS 

... 

sysContact OBJECT-TYPE 

SYNTAX DisplayString (SIZE (0..255)) 

MAX-ACCESS read-write 

STATUS current 

DESCRIPTION 

"The textual identification of the contact person for this 

managed node, together with information on how to contact 

this person. If no contact information is known, the 

value 

is the zero-length string." 

::= { system 4 }

Malaka Udawatta (malaka13 at gmail dot com) 19-Sep-2007 05:17


When I try to get a 64 bit counter variable (e.g. ifHCInOctets) using snmpget function, following error message was appeared.



Error in packet: (noSuchName) There is no such variable name in this MIB



The solution for this is to use snmp2_get(); function. The prameters are same as snmpget();

Eduardo 12-Apr-2007 12:30


The online documentation says that the function returns "FALSE" on error but, actually, it returns NULL on error.

tridman 21-Nov-2006 02:48


The timeout is in micro seconds. Thus 1.000.000 means 1 Second.

michael dot mauch at gmx dot de 10-Nov-2006 09:07


I have no idea what the timeout value is, but 1 second is really really 1 000 000 000 nano seconds (cf. http://en.wikipedia.org/wiki/SI_prefix).

fbleau 11-Jul-2006 11:15


The default value of Timeout is 1000000  nanoseconde (1 sec) and the retrie is 5 thsi value is set by Net-SNMP library.



#!/usr/local/bin/php

<?php

 $time_start = microtime(true);

 $reponse = snmpget('10.5.1.1', 'public', "1.3.6.1.2.1.1.3.0",1000000,5);

 $time_end = microtime(true);

 $time = $time_end - $time_start;



 echo "Delay in $time secondes\n";

?>

Jim 14-May-2006 07:52


Unfortunately, It appears that you can not put multiple objects into the snmpget function, ie: sysUpTime.0 ifInOctets.1 ifOutOctets.1.  For what it's worth, the time argument is in nano-seconds as previously mentioned.  There is a lot of conflicting information out there about this.

dstjohn-NO-SPAM at mediacast1 dot com 11-Sep-2005 02:16


2 year tidbit update :)



<?php

// author: dstjohn at mediacast1.com

// updated: 09-11-2005

// set some vars

$snmpcommunity = 'PUBLIC'; //snmp community name

$ips = 'test1.com,test2.com'; //ips or dns to get snmp data from

$system_number = '1';

//end da vars



//start da loop d loop

for ($i = 0; $i <= $system_number; $i++) {

$sysip = explode(",",$ips);



//get system name

$sysname[0] = snmpget($sysip[$i], $snmpcommunity, "sysName.0");

$sysname[1] = eregi_replace("STRING:","",$sysname[0]);

echo 'System Name: '.$sysname[1].'<br>';



//system description

$sysdesc[0] = snmpget($sysip[$i], $snmpcommunity, "sysDescr.0");

$sysdesc[1] = eregi_replace("STRING:","",$sysdesc[0]);

echo 'System Description: '.$sysdesc[1].'<br>';



//system location

$sysloc[0] = snmpget($sysip[$i], $snmpcommunity, "sysLocation.0");

$sysloc[1] = eregi_replace("STRING:","",$sysloc[0]);

echo 'System Location: '.$sysloc[1].'<br>';



//current tcp connections

$tcpcons[0] = snmpget($sysip[$i], $snmpcommunity, "tcpCurrEstab.0");

$tcpcons[1] = eregi_replace("Gauge32:","",$tcpcons[0]);

echo 'Open TCP/IP Connections: '.$tcpcons[1].'<br>';



//get system uptime

$sysuptime[0] = snmpget($sysip[$i], $snmpcommunity, "system.sysUpTime.0");

$sysuptime[1] = eregi_replace("Timeticks:","",$sysuptime[0]);

echo 'System Uptime: Timeticks -'.$sysuptime[1].'<br>';



//windows only

//installed memory

if(eregi('Windows',$sysdesc[1])){

$mem[0] = snmpget($sysip[$i], $snmpcommunity, "HOST-RESOURCES-MIB::hrMemorySize.0");

$mem[1] = eregi_replace("INTEGER:","",$mem[0]);

$mem[2] = eregi_replace("KBytes","",$mem[1]);

echo 'Insalled Memory: '.$mem[2].' KiloBytes<br>';

}



echo '<br><br>';

}//end loop



?>

Johann Glaser 22-Feb-2004 12:39


It seems that for each snmpget() its own socket() will be opened. This is not closed after snmpget() finishes. Neither existing sockets are reused by subsequent snmpget() calls.



When querying a few switches with lots of ports the maximum file descriptor count of Apache is exhausted. Thus no more snmpget() are possible. Additionaly no more files can be read by this particular Apache process. Neither the PHP file, any include files nor any other files (like a .css file, ...).



This probably explains the observation of tkjode at phalnet dot com. Different to his case is that I'm using Linux.

dstjohn-NO-SPAM at mediacast1 dot com 22-Sep-2003 07:53


Little tidbit for snmpget function



<?php

//snmpget system stats

$host = 'localhost';

$community = 'public';



//get system name

$sysname = snmpget($host, $community, "system.sysName.0");



//get system uptime

$sysup = snmpget($host, $community, "system.sysUpTime.0");

$sysupre = eregi_replace("([0-9]{3})","",$sysup);

$sysupre2 = eregi_replace("Timeticks:","",$sysupre);

$sysupre3 = eregi_replace("[()]","",$sysupre2);



//get tcp connections

$tcpcon = snmpget($host, $community,"tcp.tcpCurrEstab.0");

$tcpconre = eregi_replace("Gauge32:","",$tcpcon);



echo '

System Name: '.$sysname.'<br>

System Uptime: '.$sysupre3.'<br>

Current Tcp Connections: '.$tcpconre.'<br>';



?>

javierb at gmx dot net 04-Jun-2003 08:08


pooling a cisco.



$ip = '1.1.1.1';

$community ='publico';

$a = snmpget($ip,$community, "IF-MIB::ifLastChange.1")

$b = snmpget($ip,$community, "IF-MIB::ifAlias.1");

print("a = ".$a."\n"."b = ".$b."\n");



a = Timeticks: (929969969) 107 days, 15:14:59.69

b = Timeticks: (929969969) 107 days, 15:14:59.69



when the interface has not description.

tkjode at phalnet dot com 12-Feb-2002 11:49


It has been observed on NT/2000 systems that flooding devices with SNMP requests will cause NT's SNMP service to stop working.



For example, I polled 183 switches on our network just fine.  I then attempted to simulate heavy traffic to that page by refreshing and breaking connections (as any real world system would have to go through).  SNMP stopped working throughout the entire machine, including non-PHP/Webserver processes.

grice at berbee dot com 24-Aug-2000 04:05


It looks like you can use a non-standard port for SNMP


with something like this:





$foo = snmpwalk('foo.bar.com:1161', 'foofoo', '.1.3.6');





This is on PHP 3.16; I haven't managed to get PHP 4.02 to compile successfully on Solaris 2.6 yet.


--Michael