if(preg_match('/((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])\.){3}(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])/',$_SERVER['REMOTE_ADDR']))// we do not support ipv6 on our backend server
array_push($errors,'<remoteIp>: FlockLab does not support IPv6 addresses ('.$_SERVER['REMOTE_ADDR'].'). To use the <a href="https://www.flocklab.ethz.ch/wiki/wiki/Public/Man/Tutorials/Tutorial2#notes">Serial socket feature</a>, please provide an IPv4 address.');
array_push($errors,'remoteIp: FlockLab does not support IPv6 addresses ('.$_SERVER['REMOTE_ADDR'].'). To use the <a href="https://www.flocklab.ethz.ch/wiki/wiki/Public/Man/Tutorials/Tutorial2#notes">Serial socket feature</a>, please provide an IPv4 address.');