The Columbus Blue Jackets and Ottawa Senators have given up an average of almost four goals per game so far this season.
The Anaheim Ducks are averaging less than two goals per game.
These are just some things that those teams will need to address at some point this season, whether it's internally (calling players up, etc) or externally (trade).
Many teams' problems will need to be addressed externally and probably will be addressed sometime this season.
Here is one thing each team will look to address via trade at some point before the trade deadline.