cjones@monster:~/snmpscripts$ cat testcase01.pl 
#!/usr/bin/perl

use Net::SNMP;

use strict;

use warnings;


my $community           = "eX0gyN37";
my $inputfilename 	= "/home/cjones/snmpscripts/hostipaddresses.txt";
my $outputfilename 	= "/home/cjones/snmpscripts/vlan1.csv";

my $IFINDEX             = "1.3.6.1.2.1.2.2.1.1";
my $IFTYPE              = "1.3.6.1.2.1.2.2.1.3";
my $IFNAME              = "1.3.6.1.2.1.31.1.1.1.1";
my $IFALIAS             = "1.3.6.1.2.1.31.1.1.1.18";
my $IFOPERSTATUS        = "1.3.6.1.2.1.2.2.1.8";
my $VMVLAN              = "1.3.6.1.4.1.9.9.68.1.2.2.1.2";
my $HOSTNAME_OID        = "1.3.6.1.4.1.9.2.1.3.0";
my $IFNUMBER            = "1.3.6.1.2.1.2.1.0";

open my $input, '<', $inputfilename or die "$0: $inputfilename: $!\n";
open my $output, '>', $outputfilename or die "$0: $outputfilename: $!\n";

while (my $ip = <$input>) {

	$ip =~ s/\n//;
        $ip =~ s/\r//;

	print "IP: $ip\n";
	
	my ($snmp,$snmperror)   = Net::SNMP->session(
                -hostname       => $ip,
                -community      => $community
        	) or die "SNMP Session ERROR: $!";

	my $response 		= $snmp->get_request(
		$IFNUMBER,
		$HOSTNAME_OID
		) or die "SNMP get ERROR: $!";;

	my $getNumInterfaces	= $response->{"$IFNUMBER"};
	my $hostname		= $response->{"$HOSTNAME_OID"};

	die "Number of Interfaces isnt being defined for some reason\n" unless defined $getNumInterfaces;
	die "Hostname isnt being defined for some reason\n" unless defined $hostname;
	die "IP address isnt being defined for some reason\n" unless defined $ip;

	#print "$ip - $hostname: ";

}
cjones@monster:~/snmpscripts$ perl testcase01.pl 
IP: 192.168.0.254
SNMP get ERROR:  at testcase01.pl line 38, <$input> line 1.
cjones@monster:~/snmpscripts$