Here's how I do it with threads. One thread runs the sever; 10 do the smp walking; the main thread populates the database.

(No clean up code because it wasn't clear from your code what caused things to stop? Compiles clean; but untested.)

#! perl -slw
use strict;
use threads;
use Thread::Queue;

our $T //= 10;  ## 10 walkers; adjust to suit.

sub listener {
    my( $Qout ) = @_;
    require 'IO::Socket::INET::Daemon';   ## Requiring here means othe
+r threads don't carry the redundant weight

    my $host = new IO::Socket::INET::Daemon(
        host => '172.24.3.208', port => 7777, timeout => 20,
        callback => { data =>
            sub {
                my ($io, $host) = @_;
                chomp( my $line = <$io> );
                return 0 unless $line;
                $Qout->enqueue( $line );    ## send work to listener
                return !0;
            }
        },
    );
    $host->run;
    return;
}

sub walker {
    my( $Qin, $Qout ) = @_;
    while( $Qin->dequeue ) { ## receive work from listener

        my( $type, $ip, $mac, $bsid, $datecode ) = split( ',', $_ );
        $mac =~ tr[-][]d;

        my $output = qx( snmpwalk -v2c -t1 -c public $ip .1.3.6.1.4.1.
+9885.9885.1.2.0 2>&1 );
        my( $rssi, $error ) = 0;

        if( $output eq "Timeout: No Response from $ip" ) {
            $error = 'SNMP not responding. Upgrade firmware';
        }
        else {
            my @result = split( /:/, $output );
            $rssi   = $result[ 3 ];
            $rssi   =~ tr[ \n][]d;
            if( $rssi < -100 ) {
                $rssi = $rssi / 100;
            }
            $rssi = int( $rssi );
        }
        $Qout->enqueue( join $;, $mac, $ip, $bsid, $rssi );           
+      ## Send data items to DBI as one scalar
    }
}

use enum qw[ IN DBI ];

my @Qs = map Thread::Queue->new(), 1 .. 2;                            
+      ## set up two Qs

## start the listener thread
my $tListener = threads->create( \&listener, $Qs[ IN ] );             
+       ## One for the listener to send work to the walkers

## start 10 walkers
my @walkers = map{ threads->create( \&walker, @Qs[ IN, DBI ] ) } 1 .. 
+$T;   ## And one for the walkers to forward data for adding to the db

require DBI; ## Avoid loading DBI into threads

my $dbh = DBI->connect( "DBI:mysql:database=cpe_info;host=172.24.3.207
+;port=3306","account_process","neting.!" );
my $sth = $dbh->prepare( "INSERT INTO  cpe_info(mac,ip,bsid,rssi) VALU
+ES( ?, ?, ?, ? ) ON DUPLICATE KEY UPDATE ip = ?, bsid = ?, rssi = ?" 
+);

## process data produced by walkers
while( $Qs[DBI]->dequeue ) {
    my( $mac, $ip, $bsid, $rssi ) = split $;;                         
+      ## Retrieve individual data
    $sth->execute( $mac, $ip, $bsid, $rssi, $ip, $bsid, $rssi );      
+      ## bind and execute
}
$dbh->disconnect();

__END__
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