snmprealwalk

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

snmprealwalk — Return all objects including their respective object ID within the specified one

Description

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

The snmprealwalk() function is used to traverse over a number of SNMP objects starting from object_id and return not only their values but also their object ids.

Parameters

hostname: The hostname of the SNMP agent (server).
community: The read community.
object_id: The SNMP object id which precedes the wanted one.
timeout: The number of microseconds until the first timeout.
retries: The number of times to retry if timeouts occur.

Return Values

Returns an associative array of the SNMP object ids and their values on success or false on error. In case of an error, an E_WARNING message is shown.

Examples

Example #1 Using snmprealwalk()

<?php
 print_r(snmprealwalk("localhost", "public", "IF-MIB::ifName"));
?>

The above will output something like:

Array
      (
      [IF-MIB::ifName.1] => STRING: lo
      [IF-MIB::ifName.2] => STRING: eth0
      [IF-MIB::ifName.3] => STRING: eth2
      [IF-MIB::ifName.4] => STRING: sit0
      [IF-MIB::ifName.5] => STRING: sixxs
    )

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User Contributed Notes 7 notes

down

scot at indievisible dot org ¶

18 years ago

Since PHP doesn't have a nice snmptable-like function... here is a quick-and-dirty hack that works for me. Works on complete and sparse tables. The example oids are for the route (complete) and interface (often sparse) tables.

<?php
    $a = snmptable("10.1.1.1", "public", ".1.3.6.1.2.1.4.21") or die("error");
    print_r($a);
    $a = snmptable("10.1.1.1", "public", ".1.3.6.1.2.1.2.2") or die("error");
    print_r($a);

function snmptable($host, $community, $oid) {
    // TODO: get original state and restore at bottom
    snmp_set_oid_numeric_print(TRUE);
    snmp_set_quick_print(TRUE);
    snmp_set_enum_print(TRUE); 

    $retval = array();
    $raw = snmprealwalk($host, $community, $oid) or die("snmptable: unable to walk OID $oid");

    $prefix_length = 0; 

    foreach ($raw as $key => $value) {
        if ($prefix_length == 0) {
            // don't just use $oid's length since it may be non-numeric
            $prefix_elements = count(explode('.',$oid));
            $tmp = '.' . strtok($key, '.');
            while ($prefix_elements > 1) {
                $tmp .= '.' . strtok('.');
                $prefix_elements--;
            }
            $tmp .= '.';
            $prefix_length = strlen($tmp);
        }
        $key = substr($key, $prefix_length);
        $index = explode('.', $key, 2);
        isset($retval[$index[1]]) or $retval[$index[1]] = array();
        isset($firstrow) or $firstrow = $index[1];
        $retval[$index[1]][$index[0]] = $value;
    }

    // check for holes in the table and fill them in
    foreach ($retval[$firstrow] as $key => $tmp) {
        foreach($retval as $check => $tmp2) {
            if (! isset($retval[$check][$key])) {
                $retval[$check][$key] = '';
            }
        }
    }

    return($retval);
}
?>

down

Anonymous ¶

16 years ago

To check if there were any results found you have to use the empty() function.  The count() function always returns a number 1 or larger.

     $walk_result = snmprealwalk($machine_ip, $community, $snmpcodes['interface_names']);

    if (empty($walk_result)) {
        print "No network interfaces found.<br>\n";
        exit(0);
    }

down

Stephen Cope ¶

20 years ago

Here's a way to find the uptime and number of users on a machine. (Note that uptime is the uptime of the snmpd daemon, which should be fairly close to the uptime for the host.)

<?php
        $state = snmprealwalk($host, "public", ".1.3.6.1.2.1.25.1", 50, 1);
        $uptime = ereg_replace("^.*\) ([0-9]+ .*):[0-9][0-9]\.[0-9]{2}.*$", "\\1", $state['host.hrSystem.hrSystemUptime.0']);
        $users  = (int)ereg_replace("Gauge32: ", "", $state['host.hrSystem.hrSystemNumUsers.0']);
        printf('<div class="machine"><dt>%s</dt><dd>%s</dd>', $host, $desc);
        printf('<dd>up %s</dd>', $uptime);
        if ( $users ) printf('<dd>%d user%s</dd>', $users, ($users > 1) ? 's' : '');
        printf('</div>');
?>

down

Lars Troen ¶

21 years ago

snmprealwalk indexes the values using the oid instead of an integer. This is useful when you need data that is contained in the oid as well as the value. 

Here's an example for retrieving and printing vlan info:
//
// I have collected the vlan identifiers earlier from the 3com mib and they are stored in the $vlan table.
// 
  for($n=0;$n<count($vlan);$n++){
    print $vlan[$n][id]."  ".$vlan[$n][name]."<br>\n";
    $ifStackStatusTable=@snmprealwalk($switch, $community, ".1.3.6.1.2.1.31.1.2.1.3.".$vlan[$n][id]); // ifMIB.ifMIBObjects.ifStackTable.ifStackEntry.ifStackStatus
    for(reset($ifStackStatusTable);  $port = key($ifStackStatusTable);  next($ifStackStatusTable)){
      print "$port=$ifStackStatusTable[$port]<br>";
      }

down

-1

aleksander dot sztramski at kpsi dot pl ¶

15 years ago

If you wish to use version 2c or 3, use the following functions:

snmp v2c functions:

snmp2_get (string host, string community, string object_id [, int timeout [, int retries]])
snmp2_getnext (string host, string community, string object_id [, int timeout [, int retries]])
snmp2_walk (string host, string community, string object_id [, int timeout [, int retries]])
snmp2_real_walk (string host, string community, string object_id [, int timeout [, int retries]])
snmp2_set (string host, string community, string object_id, string type, mixed value [, int timeout [, int retries]])

snmp v3 functions:

snmp3_get (string host, string sec_name, string sec_level, string auth_protocol, string auth_passphrase, string priv_pr)
snmp3_getnext (string host, string sec_name, string sec_level, string auth_protocol, string auth_passphrase, string pri)
snmp3_walk (string host, string sec_name, string sec_level, string auth_protocol, string auth_passphrase, string priv_p)
snmp3_real_walk (string host, string sec_name, string sec_level, string auth_protocol, string auth_passphrase, string p)
snmp3_set (string host, string sec_name, string sec_level, string auth_protocol, string auth_passphrase, string priv_pr)

down

-1

railson at amixsi dot com dot br ¶

18 years ago

Attention: timeout is in microseconds (multiply by 1,000,000 for seconds)

down

-2

scot at indievisible dot org ¶

18 years ago

Some improvements based on testing a lot of OIDs on a lot of devices.

<?php
function snmptable($host, $community, $oid) {
    // TODO: get original state and restore at bottom
    snmp_set_oid_numeric_print(TRUE);
    snmp_set_quick_print(TRUE);
    snmp_set_enum_print(TRUE); 

    $retval = array();
    $raw = snmprealwalk($host, $community, $oid);
    if (count($raw) == 0) return ($retval); // no data
    
    $prefix_length = 0; 
    $largest = 0;
    foreach ($raw as $key => $value) {
        if ($prefix_length == 0) {
            // don't just use $oid's length since it may be non-numeric
            $prefix_elements = count(explode('.',$oid));
            $tmp = '.' . strtok($key, '.');
            while ($prefix_elements > 1) {
                $tmp .= '.' . strtok('.');
                $prefix_elements--;
            }
            $tmp .= '.';
            $prefix_length = strlen($tmp);
        }
        $key = substr($key, $prefix_length);
        $index = explode('.', $key, 2);
        isset($retval[$index[1]]) or $retval[$index[1]] = array();
        if ($largest < $index[0]) $largest = $index[0];
        $retval[$index[1]][$index[0]] = $value;
    }

    if (count($retval) == 0) return ($retval); // no data

    // fill in holes and blanks the agent may "give" you
    foreach($retval as $k => $x) {
        for ($i = 1; $i <= $largest; $i++) {
        if (! isset($retval[$k][$i])) {
                $retval[$k][$i] = '';
            }
        }
        ksort($retval[$k]);
    }
    return($retval);
}
 ?>

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snmprealwalk

Description

Parameters

Return Values

Examples

See Also

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User Contributed Notes 7 notes