I (still ...) strongly suspect that you are seeing the error-message because of print $@;.   Therefore, I specifically suggest that you should modify the if/else structure in more or less this way:

if ($@) {
   print STDERR "An exception was caught!\n";
   # (set the default IP-address here, etc ...)
} else {
   print STDERR "An exception did not occur.\n"
   # ( grab the real address here)
}
print STDERR "... so the IP-address is $ipaddr\n"; 
# (etc. etc ...)
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In other words, cause the code to explicitly log what it’s doing, one way or the other, to remove all doubt as to what it is doing.