Earlier quoted context omitted.
As others have mentioned: $ sudo apt-get update && sudo apt-get upgrade In this particular case, from 7.1 to 7.3, "dist-upgrade" is not needed (you aren't upgrading from one distribution to another (e.g. from 6 to 7)).
This is not Ubuntu. Better use 'aptitude': sudo aptitude update && aptitude full-upgrade
I've been using debian for years and always just used apt-get.