ip地址后边加个/8(16,24,32)是什么意思?
是掩码的位数，A类IP地址的默认子网掩码为255.0.0.0（由于255相当于二进制的8位1，所以也缩写成“/8”，表示网络号占了8位）;B类的为255.255.0.0（/16）;C类的为255.255.255.0(/24)。/30就是255.255.255.252。32就是255.255.255.255.
本机的DNS配置信息是在：/etc/resolv.conf
time cost is(3\d{3}?ms)
Linux 防火墙
[root@CentOS3 redis]# service iptables status
Table: filter
Chain INPUT (policy ACCEPT)
num target prot opt source destination
1 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
2 ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0
3 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
4 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:22
5 REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
Chain FORWARD (policy ACCEPT)
num target prot opt source destination
1 REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
Chain OUTPUT (policy ACCEPT)
num target prot opt source destination
[root@CentOS3 redis]# service iptables stop
iptables: Setting chains to policy ACCEPT: filter [ OK ]
iptables: Flushing firewall rules: [ OK ]
iptables: Unloading modules: [ OK ]
[root@CentOS3 redis]# service ip6tables stop
ip6tables: Setting chains to policy ACCEPT: filter [ OK ]
ip6tables: Flushing firewall rules: [ OK ]
ip6tables: Unloading modules: [ OK ]
[root@CentOS3 redis]# chkconfig iptables down
chkconfig version 1.3.49.3 - Copyright (C) 1997-2000 Red Hat, Inc.
This may be freely redistributed under the terms of the GNU Public License.
usage: chkconfig [--list] [--type <type>] [name]
chkconfig --add <name>
chkconfig --del <name>
chkconfig --override <name>
chkconfig [--level <levels>] [--type <type>] <name> <on|off|reset|resetpriorities>
[root@CentOS3 redis]# chkconfig iptables off
[root@CentOS3 redis]# chkconfig ip6tables off
`service iptables status` 查看iptables状态
`service iptables restart` iptables服务重启
`service iptables stop` iptables服务禁用