Merge pull request #1577 from f0o/snmp-scan

Added SNMP-Scanner + Docs
2026-07-28 00:24:21 +02:00 · 2015-08-01 20:29:52 +10:00
parent 429f32d7f4 531caf2823
commit bd48536189
2 changed files with 150 additions and 1 deletions
@@ -162,4 +162,24 @@ DB Updates

 RRD Updates

-SNMP Response
+SNMP Response
+
+### SNMP Scan
+
+Apart from before mentioned Auto-Discovery options LibreNMS is also able to proactively scan a network for SNMP-enabled devices using the configured version/credentials.
+
+Using the SNMP-Scanner may take long time to finish depending on the size of your network. Tests have shown that a sparsely populated /24 is scanned within 2 Minutes whereas a sparsely populated /16 will take about 11 Hours.
+
+If possible, devide your network into smaller subnet segments and scan these subnets instead. You can use an utility like the GNU Screen or tmux to avoid aborting the scan when logging out of your Shell. You can run several instances of the SNMP-Scanner simultaneously.
+
+To run the SNMP-Scanner you need to execute the `snmp-scan.php` from within your LibreNMS installation directory.
+
+Here the script's help-page as reference:
+```text
+Usage: ./snmp-scan.php -r <CIDR_Range> [-d] [-l] [-h]
+  -r CIDR_Range     CIDR noted IP-Range to scan
+                    Example: 192.168.0.0/24
+  -d                Enable Debug
+  -l                Show Legend
+  -h                Print this text                            
+```
@@ -0,0 +1,129 @@
+#!/usr/bin/env php
+<?php
+/*
+ * Copyright (C) 2015 Daniel Preussker <f0o@librenms.org>
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * SNMP Scan
+ * @author f0o <f0o@librenms.org>
+ * @copyright 2015 f0o, LibreNMS
+ * @license GPL
+ * @package LibreNMS
+ * @subpackage Discovery
+ */
+
+$ts = microtime(true);
+
+chdir(dirname($argv[0]));
+
+require 'includes/defaults.inc.php';
+require 'config.php';
+require 'includes/definitions.inc.php';
+
+if ($config['autodiscovery']['snmpscan'] == false) {
+    echo 'SNMP-Scan disabled.'.PHP_EOL;
+    exit(2);
+}
+
+require 'includes/functions.php';
+require 'includes/discovery/functions.inc.php';
+
+function perform_snmp_scan($net) {
+    global $stats, $config, $quiet;
+    echo 'Range: '.$net->network.'/'.$net->bitmask.PHP_EOL;
+    $config['snmp']['timeout'] = 1;
+    $config['snmp']['retries'] = 0;
+    $config['fping_options']['retries']  = 0;
+    $start = ip2long($net->network);
+    $end   = ip2long($net->broadcast)-1;
+    while ($start++ < $end) {
+        $stats['count']++;
+        $device_id = false;
+        $host      = long2ip($start);
+        $test      = isPingable($host);
+        if ($test['result'] === false) {
+            echo '.';
+            continue;
+        }
+        if (ip_exists($host)) {
+            $stats['known']++;
+            echo '*';
+            continue;
+        }
+        foreach (array('udp','tcp') as $transport) {
+            if ($device_id !== false && $device_id > 0) {
+                $stats['added']++;
+                echo '+';
+            } else if ($device_id === 0) {
+                $stats['failed']++;
+                echo '-';
+                break;
+            }
+            $device_id = addHost(gethostbyaddr($host), '', $config['snmp']['port'], $transport, $quiet, $config['distributed_poller_group'], 0);
+        }
+    }
+    echo PHP_EOL;
+}
+
+$opts  = getopt('r:d::l::h::');
+$stats = array('count'=> 0, 'known'=>0, 'added'=>0, 'failed'=>0);
+$start = false;
+$debug = false;
+$quiet = 1;
+$net   = false;
+
+if (isset($opts['h']) || (empty($opts) && (!isset($config['nets']) || empty($config['nets'])))) {
+    echo 'Usage: '.$argv[0].' -r <CIDR_Range> [-d] [-l] [-h]'.PHP_EOL;
+    echo '  -r CIDR_Range     CIDR noted IP-Range to scan'.PHP_EOL;
+    echo '                    This argument is only requied if $config[\'nets\'] is not set'.PHP_EOL;
+    echo '                    Example: 192.168.0.0/24'.PHP_EOL;
+    echo '  -d                Enable Debug'.PHP_EOL;
+    echo '  -l                Show Legend'.PHP_EOL;
+    echo '  -h                Print this text'.PHP_EOL;
+    exit(0);
+}
+if (isset($opts['d'])) {
+    $debug = true;
+    $quiet = 0;
+}
+if (isset($opts['l'])) {
+    echo '   * = Known Device;   . = Unpingable Device;   + = Added Device;   - = Failed To Add Device;'.PHP_EOL;
+}
+if (isset($opts['r'])) {
+    $net = Net_IPv4::parseAddress($opts['r']);
+    if (ip2long($net->network) !== false) {
+        perform_snmp_scan($net);
+        echo 'Scanned '.$stats['count'].' IPs, Already know '.$stats['known'].' Devices, Added '.$stats['added'].' Devices, Failed to add '.$stats['failed'].' Devices.'.PHP_EOL;
+        echo 'Runtime: '.(microtime(true)-$ts).' secs'.PHP_EOL;
+    } else {
+        echo 'Could not interpret supplied CIDR noted IP-Range: '.$opts['r'].PHP_EOL;
+        exit(2);
+    }
+} elseif (isset($config['nets']) && !empty($config['nets'])) {
+    if (!is_array($config['nets'])) {
+        $config['nets'] = array( $config['nets'] );
+    }
+    foreach( $config['nets'] as $subnet ) {
+        $net = Net_IPv4::parseAddress($subnet);
+        perform_snmp_scan($net);
+    }
+    echo 'Scanned '.$stats['count'].' IPs, Already know '.$stats['known'].' Devices, Added '.$stats['added'].' Devices, Failed to add '.$stats['failed'].' Devices.'.PHP_EOL;
+    echo 'Runtime: '.(microtime(true)-$ts).' secs'.PHP_EOL;
+} else {
+    echo 'Please either add a range argument with \'-r <CIDR_RANGE>\' or define $config[\'nets\'] in your config.php'.PHP_EOL;
+    exit(2);
+}
+