示例环境：
OS: FC2
NIC: eth0
host name: fc2
ip: 192.168.0.20/24
default gateway: 192.168.0.254
- 修改ip地址
即时生效:
# ifconfig eth0 192.168.0.20 netmask 255.255.255.0
启动生效:
修改/etc/sysconfig/network-scripts/ifcfg-eth0
- 修改default gateway
即时生效:
# route add default gw 192.168.0.254
启动生效:
修改/etc/sysconfig/network-scripts/ifcfg-eth0
- 修改dns
修改/etc/resolv.conf
修改后可即时生效，启动同样有效
- 修改host name
即时生效:
# hostname fc2
启动生效:
修改/etc/sysconfig/network
深入研究:
以上各配置文件由于发行版本的差异会有不同，但可以通过分析启动脚本来取得配置文件的详细信息
由于FC2的启动脚本过于繁琐，我下面的例子中分析的是SysV风格的LFS初始化shell脚本:
# grep hostname /etc/rc.d/init.d/*复制内容到剪贴板
代码:
/etc/rc.d/init.d/localnet: echo "Setting hostname to $HOSTNAME..."
/etc/rc.d/init.d/localnet: hostname $HOSTNAME
/etc/rc.d/init.d/localnet: echo "Hostname is: $(hostname)"可以看出设置hostname使用了/etc/rc.d/init.d/localnet脚本
分析此脚本可以看出相关设置是在/etc/sysconfig/network文件中
请注意实际上相关文件不一定是/etc/rc.d/init.d/localnet和/etc/sysconfig/network，一切取决于个发型版的个性设置，但以上步骤是通用的分析方法。
/etc/rc.d/init.d/localnet:
注意其中的
. /etc/sysconfig/network复制内容到剪贴板
代码:
#!/bin/bash
# Begin $rc_base/init.d/localnet - Loopback device
# Based on localnet sysklogd script from LFS-3.1 and earlier.
# Based on localnet sysklogd script from LFS-3.1 and earlier.
# Rewritten by Gerard Beekmans - [email]gerard@linuxfromscratch.org[/email]
. /etc/sysconfig/rc
. $rc_functions
. /etc/sysconfig/network
case "$1" in
start)
echo "Bringing up the loopback interface..."
ifconfig lo 127.0.0.1
evaluate_retval
echo "Setting hostname to $HOSTNAME..."
# Based on localnet sysklogd script from LFS-3.1 and earlier.
# Rewritten by Gerard Beekmans - [email]gerard@linuxfromscratch.org[/email]
. /etc/sysconfig/rc
. $rc_functions
. /etc/sysconfig/network
case "$1" in
start)
echo "Bringing up the loopback interface..."
ifconfig lo 127.0.0.1
evaluate_retval
echo "Setting hostname to $HOSTNAME..."
hostname $HOSTNAME
evaluate_retval
;;
stop)
echo "Bringing down the loopback interface..."
ifconfig lo down
evaluate_retval
;;
restart)
$0 stop
sleep 1
$0 start
;;
status)
echo "Hostname is: $(hostname)"
ifconfig lo
;;
*)
echo "Usage: $0 {start|stop|restart|status}"
exit 1
;;
esac
# End $rc_base/init.d/localnet 
