my http frequently down ,what is wrong from the log ?

my message server is iplanet message server 5.2 for solaris9 ,and the mail express usually down ,and the time span maybe 10 day or 1 day ,from the http log i can not see the useful log .and when the express can not access the pop and smtp service is ok .and the use is not very large. when i see the http log ,i have some doubt ?

1. what is the unauthenticated?

2. why i can not see the open session only the close session ?

3. why has the 127.0.0.1 access ,and i have not access the express via127.0.0.1 ?

4. how to config the http log then it will prompt more detail log ?

thanks for you !

[25/Oct/2006:14:34:20 +0800] v880 httpd[8324]: General Information: Log created (1161758060)

[25/Oct/2006:14:34:20 +0800] v880 httpd[8324]: Account Notice: close [40.15.22.27] [unauthenticated] 2006/10/25 14:32:59 0:01:21 735 80679 0

[25/Oct/2006:14:34:26 +0800] v880 httpd[8324]: Account Notice: close [222.189.61.178] [unauthenticated] 2006/10/25 14:33:04 0:01:22 2980 23573 0

[25/Oct/2006:14:34:36 +0800] v880 httpd[8324]: Account Notice: close [127.0.0.1] [unauthenticated] 2006/10/25 14:34:36 0:00:00 0 0 0

[25/Oct/2006:14:35:43 +0800] v880 httpd[8324]: Account Notice: close 40.15.44.34 chuyj 2006/10/25 14:05:06 0:30:37 0 0 1

[25/Oct/2006:14:44:09 +0800] v880 httpd[8324]: General Notice: hanjj[40.40.40.35] created message <27085066.50662708@jnpc.com.cn>

[25/Oct/2006:14:44:36 +0800] v880 httpd[8324]: Account Notice: close [127.0.0.1] [unauthenticated] 2006/10/25 14:44:36 0:00:00 0 0 0

[25/Oct/2006:14:44:43 +0800] v880 httpd[8324]: Account Notice: close 40.15.43.12 zhoun 2006/10/25 14:13:25 0:31:18 0 0 1

[1699 byte] By [robote] at [2007-11-26 11:05:08]