The lag spikes occur everywhere at some point or another (by that I mean the whole shard of LS), although, In fel dungeons it happens far more frequently.
head down into despise or any
Fel dungeon if you're there for about an hour, you WILL get at least one of these 2-6 second spikes, people that are not in
A Fel Dungeon at that particular time will NOT experience this type of lag.
As stated in this thread, it's not a specific person lagging for these spikes it's Everyone players & NPC's alike, The whole sub-server freezes for 2-6 seconds it's not unusual (lately) to see it happen several times an hour. People that are NOT on the same sub-server will not experience these spikes. fel dungeons freeze up for 2-6 seconds, another client (from the same PC) sitting in luna is able to move, when the lag spike ends, everyone there picks up where the lag-spike started (nothing happens from ANYONE during the spike).