Are you sharing this variable with other modules? If not, replace our with my. Does this: perl MSys::Hostname -E 'say hostname();' return consistently?

...and this looks odd...

print $fd $daemon_log_timestamp.' '.our $host.' mrtg[]:['.$log_entry_c
+ategory.']: '.$log_entry.'.'."\n";
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Why are you using our $host here? That doesn't make any sense that I can see ;) Another thing, is that in double-quotes, Perl variables "interpolate":

print $fd "$daemon_log_timestamp $host mrtg[]:[$log_entry_category]: $
+log_entry\n";
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That line of code is within a subroutine that writes to the daemon log. I'm also fairly new to Perl. I have experience with other languages, but Perl is... different :)

# Get our hostname for logging and notifications
our $host = hostname();

# Subroutine to append a new MRTG entry to the daemon log
sub write_mrtg_log{
  my( $arg1, $arg2 ) = @_;
  my $log_entry = defined $arg1 ? $arg1 : 'Empty Log Entry';
  my $log_entry_category = defined $arg2 ? $arg2 : 'SCHEDULER';
  my $daemon_log_timestamp = localtime()->strftime('%b %d %H:%M:%S');
  open(my $fd, ">>/var/log/daemon");
  print $fd $daemon_log_timestamp.' '.our $host.' mrtg[]: ['.$log_entr
+y_category.']: '.$log_entry.'.'."\n";
  close $fd;
}
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I'm still trying to understand our, my, and local. I honestly don't understand why I need to put 'our' in front of a variable just because it is within an IF/ELSE block. I can understand isolating a subroutine or referenced module, but having it also for IF/ELSE, WHILE, etc. is confusing me. At this point it seems like 'our' creates a global? Or is it preferred to just pass everything as arguments to subroutines?

Yes, the command you gave me (it needed a hyphen?) is returning the hostname consistently. The daemon log entries also use the value and they have it filled in most of the time. The exceptions are during network outages, which I've no idea how they're related yet.

Thanks for the suggestions on cleaning up the syntax. I'm still learning how to write Perl well, and I appreciate any advice.

sub get_local_ip {
   my $sock = IO::Socket::INET->new(
    PeerAddr=> $mrtgc2,
    PeerPort=> 5432,
    Proto   => "tcp");

  return $sock->sockhost;
}

my $localip = get_local_ip();
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sub get_local_ip {
  my $host = shift;
  my $port = shift;

   my $sock = IO::Socket::INET->new(
    PeerAddr=> $host,
    PeerPort=> $port,
    Proto   => "tcp");

  return $sock->sockhost;
}

my $localip = get_local_ip($mrtgc2, 5432);
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I also find your usage of 'our' to be quite strange.

I'm new to Perl, so I'm sure some of it is going to look "strange" :)

Thank you for the rewrite. I'm still having difficulty understanding our, my, and local. If I change it from 'our' to 'my', how do I properly "access" $localip from within nested IF/ELSE and WHILE? That in a nutshell is my biggest challenge with Perl currently, is watching the warnings and errors complain about my syntax for using variables.

Verifying whether this has worked or not will take some time. This script is running out in the field, and I would need to wait for another network event to see what happens. Under normal conditions I have no warnings or errors returned from running the script. It also runs on many other systems and returns no errors or warnings at all. Since it's all logged I can verify what occurs on the other systems and that the script is working.

long answer: Variable Scoping in Perl: the basics

short answer:
• forget about 'our' and 'local' (for now)
• identify the relevant blocks (= something enclosed in '{ }')
• if you need the variable outside of the block, define it outside

minimalistic example to set a value inside a conditional / loop / block:
(I intentionally used the variable '$value' inside the block to demonstrate 'my'. It is not mandatory, you can also assign directly.)

my $variable;

if (1 == 1) {
  my $value = 'a';
  $variable = $value;
}
else {
  my $value = 'b';
  $variable = $value;
}

# => '$variable' now contains 'a'
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