Honestly, its not a network problem. CraftBukkit++ is having a spasm attack. The current build of CB++ Justin put on is VERY buggy. We went from version 198 to version 248.
Well Aikar isn't stalking Justin's CraftBukkit updates. Actually we were in a older version of CraftBukkit++, version 189 if i remember correctly. We are now at 248, the update was in effect when the rate of mobs decreased.
Sorry for my misinformation, a few months ago both SMP1 and 2 went down, I talked to Justin and he said it was a network problem. My bad.