It could be a faulty cable, or a mismatch between data rates. Check this: http://forum.mikrotik.com/viewtopic.php?t=81923 If that doesn't help post your Tools -> Profile And take a look at interface statistics to see if you are maybe having a broadcast storm (A lot of packets). here is a screen sho...

i noticed that the management shows a high usage when the router CPU gets peaked to a 100%

i am having a issue with router CPU usage peaking to 100% randomly, i have attached a log screenshot which i noticed. looking for some advice as i am very new to this technology.