nmap-3.81扫描本地网络特别慢的问题

zxr1018

nmap-3.81扫描本地网络特别慢，具体请看下面！

C:\Program Files\nmap-3.81>;nmap -sP 192.168.110.1-254

Starting nmap 3.81 ( http://www.insecure.org/nmap ) at 2005-08-03 17:39 中国标准时间
RTTVAR has grown to over 2.3 seconds, decreasing to 2.0
RTTVAR has grown to over 2.3 seconds, decreasing to 2.0
RTTVAR has grown to over 2.3 seconds, decreasing to 2.0
RTTVAR has grown to over 2.3 seconds, decreasing to 2.0
Host 192.168.110.1 appears to be up.
MAC Address: 00:C0:26:2F:EE:0A (Lans Technology CO.)
Host 192.168.110.6 appears to be up.
MAC Address: 00:A1:B0:01:AE:64 (Unknown)
Host 192.168.110.7 appears to be up.
MAC Address: 00:05:5D:6D:41:9D (D-Link Systems)
Host 192.168.110.10 appears to be up.
MAC Address: 00:05:5D:0A:1B:02 (D-Link Systems)
Host 192.168.110.12 appears to be up.
MAC Address: 00:0A:EB:09:58:A7 (Shenzhen Tp-link Technology Co
Host 192.168.110.39 appears to be up.
MAC Address: 00:A1:B0:01:BB:BE (Unknown)
Host 192.168.110.42 appears to be up.
MAC Address: 00:80:C8:E8:F4:A0 (D-link Systems)
Host 192.168.110.149 appears to be up.
MAC Address: 00:E0:4C:00:10:94 (Realtek Semiconductor)
Host 192.168.110.221 appears to be up.
MAC Address: 00:E0:4C:3C:62:38 (Realtek Semiconductor)
Host 192.168.110.224 appears to be up.
MAC Address: 00:12A:B7:C1:F4 (Unknown)
Host 192.168.110.225 appears to be up.
MAC Address: 00:A1:B0:01:0B:54 (Unknown)
Nmap finished: 254 IP addresses (11 hosts up) scanned in 1052.683 seconds

C:\Program Files\nmap-3.81>;

请问
RTTVAR has grown to over 2.3 seconds, decreasing to 2.0
是怎么回事？

nmap所在机器的ip是192.168.110.11
WinPcap 3.1 beta4

系统环境在 win2k、winxp 下试过！请大家帮忙解决下

虚怀若谷

nmap 在unix,linux下都很快的 。在ms下比较慢，应该是移植问题