127.0.0.1与localhost

rhel 5
[root@ns100 vm]# ping localhost
PING localhost.atyu.com (202.106.195.29) 56(84) bytes of data.
64 bytes from 202.106.195.29: icmp_seq=1 ttl=249 time=20.3 ms
64 bytes from 202.106.195.29: icmp_seq=2 ttl=249 time=18.1 ms
64 bytes from 202.106.195.29: icmp_seq=3 ttl=249 time=13.7 ms
64 bytes from 202.106.195.29: icmp_seq=4 ttl=249 time=14.7 ms

--- localhost.atyu.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 7121ms
rtt min/avg/max/mdev = 13.764/16.771/20.382/2.645 ms
[root@ns100 vm]# ping local
ping: unknown host local
[root@ns100 vm]# ping 127.0.0.1
PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data.
64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.028 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.026 ms

--- 127.0.0.1 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1000ms
rtt min/avg/max/mdev = 0.026/0.027/0.028/0.001 ms
[root@ns100 vm]#


[root@ns100 vm]# cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1               ns100.atyu.com




OpenBSD 4.2

# ping local                                                            
^C
# ping localhost
PING localhost.yuyizhi.org (127.0.0.1): 56 data bytes
64 bytes from 127.0.0.1: icmp_seq=0 ttl=255 time=0.495 ms
64 bytes from 127.0.0.1: icmp_seq=1 ttl=255 time=0.118 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=255 time=0.092 ms
--- localhost.yuyizhi.org ping statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/std-dev = 0.092/0.235/0.495/0.184 ms
# ping 127.0.0.1
PING 127.0.0.1 (127.0.0.1): 56 data bytes
64 bytes from 127.0.0.1: icmp_seq=0 ttl=255 time=0.189 ms
64 bytes from 127.0.0.1: icmp_seq=1 ttl=255 time=0.088 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=255 time=0.092 ms
--- 127.0.0.1 ping statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/std-dev = 0.088/0.123/0.189/0.046 ms
#


# cat /etc/hosts                                                               
#       $OpenBSD: hosts,v 1.11 2002/09/26 23:35:51 krw Exp $
#
# Host Database
#
# RFC 1918 specifies that these networks are "internal".
# 10.0.0.0      10.255.255.255
# 172.16.0.0    172.31.255.255
# 192.168.0.0   192.168.255.255
#
::1 localhost.yuyizhi.org localhost
127.0.0.1 localhost.atyu30.com localhost
::1 ns.atyu30.com ns
10.0.0.200 ns.atyu30.com ns

 

xp sp2

 

C:\>ping localhost

Pinging 00000000-365d56 [127.0.0.1] with 32 bytes of data:

Reply from 127.0.0.1: bytes=32 time=13ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128

Ping statistics for 127.0.0.1:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 0ms, Maximum = 13ms, Average = 3ms

 

C:\>ping local

Pinging local.localdomain [202.106.195.29] with 32 bytes of data:

Reply from 202.106.195.29: bytes=32 time=36ms TTL=128
Request timed out.
Reply from 202.106.195.29: bytes=32 time=23ms TTL=128
Reply from 202.106.195.29: bytes=32 time=22ms TTL=128

Ping statistics for 202.106.195.29:
    Packets: Sent = 4, Received = 3, Lost = 1 (25% loss),
Approximate round trip times in milli-seconds:
    Minimum = 22ms, Maximum = 36ms, Average = 27ms

C:\>

 

C:\>ping 127.0.0.1

Pinging 127.0.0.1 with 32 bytes of data:

Reply from 127.0.0.1: bytes=32 time=2ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128

Ping statistics for 127.0.0.1:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 0ms, Maximum = 2ms, Average = 0ms

C:\>

 

C:\WINDOWS\system32\drivers\etc\hosts

# copyright (c) 1993-1999 microsoft corp.
#
# this is a sample hosts file used by microsoft tcp/ip for windows.
#
# this file contains the mappings of ip addresses to host names. each
# entry should be kept on an individual line. the ip address should
# be placed in the first column followed by the corresponding host name.
# the ip address and the host name should be separated by at least one
# space.
#
# additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
#
# for example:
#
#      102.54.94.97     rhino.acme.com          # source server
#       38.25.63.10     x.acme.com              # x client host

127.0.0.1       localhost