/etc/sysconfig/network-scripts/ifcfg-eth0 设置IP网关等参数
DEVICE=eth0
HWADDR=00:0C:29:C5:43:34
TYPE=Ethernet
UUID=c3d6f295-096b-4f80-a314-0cec776d1cdf
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=static
BROADCAST=192.168.138.255
IPADDR=192.168.138.100
NETMASK=255.255.255.0
NETWORKING_IPV6=no
GATEWAY=192.168.138.2
DNS1=202.106.0.20
DOMAIN=202.106.46.151
/etc/resolv.conf 设置DNS服务器地址
nameserver 202.106.0.20
nameserver 8.8.4.4
nameserver 144.144.144.144
search 202.106.46.151
临时设置所用的参数：
ifconfig eth0 192.168.1.1 netmask 255.255.255.0 设置IP以及mask地址
route add default gw 192.168.1.1 设置网关
route del default 删除默认网关
route -n 查看网关