Yeah, Lag sucks, none of us want it and we have a few things for you to try.
#1 Try connecting to your modem/router directly rather than over WiFi. You'd be amazed how often this solves it.
#2: You're playing a game! So shut down any programs that might be taking up bandwidth, such as video streaming, multiple-tab Internet browsing and other online games. This step is really important if you don't have a great internet connection to begin with. Remember DD II is an online game - all that action is happening on a server not on your machine at home!
So you've tried the above and you're still experiencing lag? Help us troubleshoot by do the following:
While in the game, press ` (~ key) to bring up the console.
Type "lcc stat netinfo" and press enter.
A bunch of stats will be displayed on the left side of the screen. Please capture video of the lag occuring while the stats are visible using a utility like Fraps or ShadowPlay (nvidia only).
Submit your video by sending us a bug report, with any information on what steps were taken before the lag began and details on your connection type (DSL, dial-up, etc.), connection speed and location.
Once you've submitted your bug report, our development team will be reviewing your case with an eye for improving the product as a whole. We appreciate the help!