SNMP Test for mib

[Anonymous Monk]

has any one use the SNMP_Session or SNMP_util package to do a snmpwalk to test if a device supports a specific mib. I know I could do a run the snmpwalk command and return the result in variable. But I was looking for a perl solution

[leighsharpe]

You could try using Net::SNMP
If you do a get_request on an OID which is not supported by the device, it returns and error, and the error_status() is set to 2 (noSuchName). For example:

#! /usr/local/bin/perl
use strict;
use Net::SNMP;
my ($session, $error) = Net::SNMP->session(
  -hostname  => shift || '192.168.5.242',
  -community => shift || 'public',
  -port      => shift || 161 
);
if (!defined($session)) {
  printf("ERROR: %s.\n", $error);
  exit 1;
}
my $sysUpTime = '1.3.6.1.2.1.1.3.0.1';
my $result = $session->get_request(
  -varbindlist => [$sysUpTime]
);
if (!defined($result)) {
  printf("ERROR: %s.\n", $session->error);
  my $error_status=$session->error_status;
  printf("Error Status: %s \n", $error_status);
  $session->close;
  if ($error_status == 2) {
    print "This device does not support the MIB requested.\n";
  }
    
  exit 1;
}
printf("sysUpTime for host '%s' is %s\n",
  $session->hostname, $result->{$sysUpTime} 
);
$session->close;
exit 0;

What's wrong with this OID is that I have added '.1' to the end of a normal sysUptime OID.

[gman]

Hello

Here is an solution I use to walk a particular tree

This includes RRD code also, but you can look beyond that

#!/usr/bin/perl

use strict;
use Net::SNMP qw(:snmp);
use Data::Dumper;
use lib qw( /usr/local/rrdtool-1.2.13/lib/perl );
use RRDs;
use File::Copy;

my $hostname = shift || "xxx.xxx.xxx.xxx";
my $community = shift || "xxx";
my $rrdname = $hostname;
$rrdname =~ s/\.//g;
my $rrd = "/<rrdpath>.$rrdname";
my $localaddr = "xxx.xxx.xxx.xxx";
my $version = "snmpv2c";
my $port = 161;
my $debug = 1;

my $ifTable = "1.3.6.1.4.1.9148.3.2.1.1"; #APSYSMGMT-MIB::apSys";

my %statHash = (
1=>'apCPUUtil',
2=>'apMemoryUtil',
3=>'apHealthScore',
4=>'apRedundancy',
5=>'apGlobalConSess',
6=>'apGlobalCPS',
7=>'apNATCapacity',
8=>'apARPCapacity',
9=>'apState',
10=>'apLicenseCapacity',
11=>'apSipStatsActiveLocalContacts',
12=>'apMgcpGWEndpoints',
13=>'apH323Registration',
);

my %names = ();
my %fullstat = ();

my ($session, $error) = Net::SNMP->session(
      -version     => $version,
      -nonblocking => 1,
      -hostname    => $hostname,
      -community   => $community,
      -port        => $port,
      -debug       => 1,
   );

if (!defined($session)) {
      printf("ERROR: %s.\n", $error);
      exit 1;
  }

my $result = $session->get_bulk_request(
      -callback       => [\&table_cb, {}],
      -maxrepetitions => 10,
      -varbindlist    => [$ifTable]
   );

   if (!defined($result)) {
      printf("ERROR: %s.\n", $session->error);
      $session->close;
      exit 1;
   }
#print Dumper($result);

snmp_dispatcher();

   $session->close;
#print Dumper(%fullstat);
foreach my $stat_index (sort keys %fullstat) {
        print "$stat_index\n";
        my $rrd = $rrd . ".$stat_index.rrd";

        foreach my $realm_name (sort keys %{$fullstat{$stat_index}}) {
            print "*\t$realm_name => $fullstat{$stat_index}{$realm_nam
+e}\n";
        }
    if(! -e $rrd) {
            my $startTime = time()-3600;
            my $meas_hashRef = \%{$fullstat{$stat_index}};
            my $step = 3*60;  #300 seconds = 5min
            print "Calling createRRD ($startTime,$rrd,$step,$meas_hash
+Ref)\n";
            createRRD($startTime,$rrd,$step,$meas_hashRef);
         } else {  #update
                updateRRD($rrd,\%{$fullstat{$stat_index}});
                #my $return = copy("$rrd","/var/www/voipdata/$rrd");
                #if( ! $return) { die "Could not rename file $return $
+!"; };
        }

}

exit 0;
sub table_cb
   {
      my ($session, $table) = @_;

      if (!defined($session->var_bind_list)) {

         printf("ERROR: %s\n", $session->error);

      } else {
# print Dumper($session->var_bind_list);

         # Loop through each of the OIDs in the response and assign
         # the key/value pairs to the anonymous hash that is passed
         # to the callback.  Make sure that we are still in the table
         # before assigning the key/values.

         my $next;

         foreach my $oid (oid_lex_sort(keys(%{$session->var_bind_list}
+))) {

            if (!oid_base_match($ifTable, $oid)) {
               $next = undef;
               last;
            }
            $next = $oid;
            $table->{$oid} = $session->var_bind_list->{$oid};
         }

         # If $next is defined we need to send another request
         # to get more of the table.

         if (defined($next)) {

            $result = $session->get_bulk_request(
               -callback       => [\&table_cb, $table],
               -maxrepetitions => 10,
               -varbindlist    => [$next]
            );

            if (!defined($result)) {
               printf("ERROR: %s\n", $session->error);
            }

         } else {

            # We are no longer in the table, so print the results.
            foreach my $oid (oid_lex_sort(keys(%{$table}))) {
               printf("*** %s => %s\n", $oid, $table->{$oid});
                my ($stat,$index) = (split(/\./,$oid))[-2,-1];
                # build names hash
                 #if($oid =~ /$ifTable\.2\.\d+$/) { #this is the apSig
+RealmStatsRealmName
                        $names{$index} = $table->{$oid};
                #}
                printf("Index: %s, %s, %s\n",$names{$index},$statHash{
+$stat},$table->{$oid});
                $fullstat{$statHash{$stat}}{$statHash{$stat}} = $table
+->{$oid};
            }
         }
      }
   }
sub createRRD {
        my ($starttime,$rrd,$step,$meas_hashRef) = @_;
        print "In createRRD: ($starttime,$rrd,$step,$meas_hashRef)\n";
        my $DS_string = "$rrd --start $starttime --step $step ";
        foreach(sort keys %$meas_hashRef) {
                my $key = $_;
                $key =~ s/\./-/g;
                $DS_string = $DS_string . "DS:$key:GAUGE:$step:U:U ";
                print "$DS_string\n";
        }
        $DS_string = $DS_string .
                "RRA:AVERAGE:0.5:1:3000 " .
                "RRA:MIN:.5:1:3000 " .
                "RRA:MAX:.5:1:3000 " .
                "RRA:LAST:.5:1:3000 ";
print "$DS_string\n";
        my $return = `/usr/voip/bin/rrdtool create $DS_string`;
        print $return;

        my $ERROR = RRDs::error;
        die "$0: unable to create $rrd : $ERROR" if $ERROR;

}
sub updateRRD {
        my ($rrd,$hashRef) = @_;
        my $epoc = time();
        #my %hash = %$hashRef;
        print "********* Start Of OID ******************\n($rrd,$hashR
+ef)\n";
        my $data_string = '';
        print "DEBUG: building updateRRD data string\n";
        #print Dumper($hashRef);
foreach my $item (sort keys %$hashRef) {
        my $value = $hashRef->{$item};
        if($value =~ /\./) { $value =100; };
        print "$item => $value\n";
        $data_string = $data_string . "$value:";
}
        $data_string =~ s/:$//g;
        print "rrdtool update $rrd $epoc:$data_string\n";
        RRDs::updatev $rrd, $epoc .":" . $data_string;
                if (my $ERROR = RRDs::error) {
                        warn "$0: unable to update $rrd : $ERROR";
                }
} #end sub