tertullian01 has asked for the wisdom of the Perl Monks concerning the following question:

I am currently working on script that will use the Net::SNMP module to check a service on a remote machine and if it isn't running then it will send a trap to an event manager. I can check the service successfully and I can send an empty trap successfully, however I have not been able to send a trap with any information actually in it. Here is a snippet of code I am using.
I have already successfully made the SNMP connection: 
my $svSvcName = '1.3.6.1.4.1.77.1.2.3.1.1';
my $message = "THIS IS AN SNMP TEST";
my @oids = ($svSvcName, OCTET_STRING, $message);
#my @oids;

my $result = $session->trap(
                            -agentaddr    => '172.16.4.32',
                            -varbindlist  => \@oids
                            #-varbindlist  => [$svSvcName, OCTET_STRIN
+G, "$message"]
);

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

[download]
This is the error I get using this code: ERROR: Unknown ASN.1 type [OCTET_STRING].

Replies are listed 'Best First'.
Re: Send SNMP trap
by LazerRed (Pilgrim) on Sep 23, 2003 at 20:49 UTC
    I've a couple quick thoughts/questions on this...

    Check where your building your Net::SNMP session, and verify what version of SNMP you are using. The docs for Net::SNMP, at the end of the traps section, states:

    NOTE: This method can only be used when the version of the object is set to SNMPv1.

    One other thing that poped into my head, is networks. I hope that your two machines are on the same subnet as your manager... Most routers drop snmp by default, just a thought. Should have read your comment more carefully, Doah!

    Update:Have you tried changing:
    my @oids = ($svSvcName, OCTET_STRING, $message);

    To:
    my @oids = ($svSvcName, 0x01, $message);

    A longshot, but I'm rather inexperienced with sending traps.

    LR

    Whip me, Beat me, Make me use Y-ModemG.
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      The session is using SNMPv1. I tried changing OCTET_STRING to 0x01 and it ended in the same result. 
      Unknown ASN.1 type [0x01]

      [download]
      I am including the full code so anyone can take a look at what is going on: 
      use strict;
use Net::SNMP qw(:snmp);
my ($session, $error) = Net::SNMP->session(
                                           -hostname    => shift || '$
+host',
                                           -community   => 'public',
                                           -version     => 'snmpv1',
                                           -port        => shift || 16
+2
);

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

my $svSvcName = '1.3.6.1.4.1.77.1.2.3.1.1';
my $message = "THIS IS AN SNMP TEST";
my @oids = ($svSvcName, "OCTET_STRING", $message);
#my @oids;

my $result = $session->trap(
                            -agentaddr    => '$monitor',
                            -varbindlist  => \@oids
                            #-varbindlist  => [$svSvcName, OCTET_STRIN
+G, "$message"]
);

if (!defined($result)) {

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

    $session->close;

    exit 1;

}

$session->close;

      [download]
      Also I don't know if this is of importance but the script is running on a Windows 2000 machine with perl 5.8
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use Net::SNMP qw(:asn1);

# missing $monitor?
my $monitor = '192.168.254.1';

# remove quotes from OCTET_STRING, it's a constant.
my @oids = ($svSvcName, OCTET_STRING, $message);

        [download]

        the above changes make it work for me.

        # snmptrapd -f -P
2003-09-23 15:20:06 NET-SNMP version 5.0.6 Started.
2003-09-23 15:20:25 192.168.254.1(via 192.168.254.1) TRAP, SNMP v1, co
+mmunity public
        SNMPv2-SMI::enterprises Enterprise Specific Trap (0) Uptime: 0
+:00:01.00
        SNMPv2-SMI::enterprises.77.1.2.3.1.1 = STRING: "THIS IS AN SNM
+P TEST"
2003-09-23 15:20:48 192.168.254.1(via 192.168.254.1) TRAP, SNMP v1, co
+mmunity public
        SNMPv2-SMI::enterprises Enterprise Specific Trap (0) Uptime: 0
+:00:01.00
        SNMPv2-SMI::enterprises.77.1.2.3.1.1 = STRING: "THIS IS AN SNM
+P TEST"
2003-09-23 15:21:08 192.168.254.1(via 192.168.254.1) TRAP, SNMP v1, co
+mmunity public
        SNMPv2-SMI::enterprises Enterprise Specific Trap (0) Uptime: 0
+:00:00.00
        SNMPv2-SMI::enterprises.77.1.2.3.1.1 = STRING: "THIS IS AN SNM
+P TEST"

        [download]
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