Beware, you can fiddle with your network settings hours and easily ending in a situation worst than when you started. My recommendation is that u find an application that will handle your network settings for u. Those apps can analyze your traffic and network settings and optimize them. They can also diagnose any problem and correct it. Finally, they let you rollback any changes made thru them.
I was always skeptical about this kind of software until i got one for "free" bundled with my mobo. The app is named "asus ROG Gamefirst II", and it shapes your network traffic by prioritize games connections over apps. For weeks, i decided to not install the software, thinking that it just another useless "bloatware" as thousand others packaged with mobos. At some point, I decided to giving it a try mostly because i was not satisfied by the fact that, even if my FPS was near perfect in FH2, the hit detection wasn't working as it should (and as i experienced on my friend rig with much lower specs). The game was also "rubberbanding" and i got a strange feeling of lag like hanging in game static models. The result is that since it's installed and running in background, i can kill someone with SMG even when i'm connected to european servers (i'm canadian), what was nearly impossible before. I can also jump thru windows on first attempt.
Now the bad news, Gamefirst app is not free and cannot be bough retail. Fortunately, it's only a rebranding for a tier party application called "cFosSpeed" that u can find at this address
http://www.cfos.de/en/cfosspeed/cfosspeed.htm?__ntrack_pv=1. The app is not cheap (around 15$) but you can probably find a free software alternative. I can't assure you that it will fix your particular issue, but for me it worked far beyond my expectations, and that's why i took some of my time to share my experience. Hope it can help you (or someone else). BTW, I'm not linked with CfosSoftware or Asus.