last命令顯示已經登出的用戶的問題

環境 AIX 5200-04

問題 在使用telnet登錄的用戶登出後，last，who等命令仍然會顯示該用戶在連接中：
#last
root pts/5 node1 Oct 26 09:19 still logged in.
root pts/3 node2 Oct 26 08:54 still logged in.
root pts/2 node3 Oct 26 08:52 still logged in.
root pts/1 node4 Oct 26 08:37 still logged in.
#who
root pts/1 Oct 26 08:37 (node4)
root pts/2 Oct 26 08:52 (node3)
root pts/3 Oct 26 08:54 (node2)
root pts/5 Oct 26 09:19 (node1)