warning about switches with same mac, take first one

diff --git a/neighbours.pl b/neighbours.pl
index b99a352..8e42b9c 100755 (executable)
--- a/neighbours.pl
+++ b/neighbours.pl
@@ -19,7 +19,13 @@ while(<$f>) {
        #my ( $ip, $name, $mac ) = split(/ /,$_);
        my ( $name, $mac ) = split(/ /,$_);
        $mac = lc($mac);
-       $mac2name->{$mac} = $name;
+       if ( defined $mac2name->{$mac} ) {
+               if ( $mac2name->{$mac} ne $name ) {
+                       warn "ERROR: GOT $mac with $mac2name->{$mac} and now trying to overwrite it with $name\n";
+               }
+       } else {
+               $mac2name->{$mac} = $name;
+       }
 }
 
 sub mac2name {