Download the new RouterOS 6.12 release over the torrent network: http://www.mikrotik.com/download/routeros-ALL-6.12.torrent

Otherwise please visit http://www.mikrotik.com/download to pick exact version!

6.12 changelog:

*) l2tp - fixed "no buffer space available" problem;

*) ipsec - support IPv4 over IPv6 and vice versa;

*) pppoe - report correctly number of active links;

*) updated timezone information;

*) many fixes for CRS managed switch functionality - particularly improved VLAN support, port isolation, defaults;

*) added trunk support for CRS switches;

*) added policing support for CRS switches;

*) www - added support for HTTP byte ranges;

*) lte - provide signal strength using snmp and make 'info once' work in console;

Source