1.基本网络配置
将Linux主机接入到网络，需要配置网络相关设置
一般包括如下内容：
主机名
IP/netmask
路由：默认网关 DNS服务器 主DNS服务器 次DNS服务器 第三个DNS服务器
CentOS 6 之前版本网卡名称
接口命名方式：CentOS 6
以太网：eth[0,1,2,...]
ppp：ppp[0,1,2,...]
网络接口识别并命名相关的udev配置文件：
/etc/udev/rules.d/70-persistent-net.rules
查看网卡：
dmesg |grep –i eth
ethtool -i eth0
卸载网卡驱动：
modprobe -r e1000
rmmod e1000
装载网卡驱动：
modprobe e1000
临时修改网卡名称
[root@centos6 ~]#ip link set eth0 down
[root@centos6 ~]#ip link set eth0 name abc
[root@centos6 ~]#ip link set abc up
2.网络配置命令
静态指定:
ifconfig, route, netstat
ip: object {link, addr, route}, ss, tc
system-config-network-tui，setup
配置文件
动态分配：DHCP: Dynamic Host Configuration Protocol
[root@c7-137-mariadb-bak ~]# cat /etc/resolv.conf
search wangxiaochun.com #自动补全后缀
nameserver 10.0.0.2
[root@c7-137-mariadb-bak ~]# ping www
PING www.wangxiaochun.com (123.56.174.200) 56(84) bytes of data.
64 bytes from 123.56.174.200: icmp_seq=1 ttl=128 time=45.2 ms
64 bytes from 123.56.174.200: icmp_seq=2 ttl=128 time=45.1 ms
64 bytes from 123.56.174.200: icmp_seq=3 ttl=128 time=45.2 ms
^C
判断是否是自动获取的IP
[root@c7-147 ~]# ss -ntlu
Netid State Recv-Q Send-Q Local Address:Port Peer Address:Port
udp UNCONN 0 0 *:670 *:*
udp UNCONN 0 0 127.0.0.1:914 *:*
udp UNCONN 0 0 *:111 *:*
udp UNCONN 0 0 *:34187 *:*
udp UNCONN 0 0 :::670 :::*
udp UNCONN 0 0 :::58121 :::*
udp UNCONN 0 0 :::111 :::*
tcp LISTEN 0 128 *:111 *:*
tcp LISTEN 0 128 *:22 *:*
tcp LISTEN 0 100 127.0.0.1:25 *:*
tcp LISTEN 0 128 *:54429 *:*
tcp LISTEN 0 128 :::111 :::*
tcp LISTEN 0 128 :::22 :::*
tcp LISTEN 0 100 ::1:25 :::*
tcp LISTEN 0 128 :::42277 :::*
[root@c7-147 ~]# ss -ntlu |grep 68 #是否有68号开启
3.ifconfig命令
来自于net-tools包，建议使用 ip 代替
[root@c7-147 ~]# rpm -qi net-tools
Name : net-tools
Version : 2.0
Release : 0.25.20131004git.el7
Architecture: x86_64
Install Date: Wed 08 Sep 2021 08:43:13 PM CST
Group : System Environment/Base
Size : 938978
License : GPLv2+
Signature : RSA/SHA256, Fri 23 Aug 2019 05:36:04 AM CST, Key ID 24c6a8a7f4a80eb5
Source RPM : net-tools-2.0-0.25.20131004git.el7.src.rpm
Build Date : Fri 09 Aug 2019 09:10:26 AM CST
Build Host : x86-02.bsys.centos.org
Relocations : (not relocatable)
Packager : CentOS BuildSystem <http://bugs.centos.org>
Vendor : CentOS
URL : http://sourceforge.net/projects/net-tools/
Summary : Basic networking tools
Description :
The net-tools package contains basic networking tools,
including ifconfig, netstat, route, and others.
Most of them are obsolete. For replacement check iproute package.
ifconfig [interface]
ifconfig -a
ifconfig IFACE [up|down]
ifconfig interface [aftype] options | address ...
ifconfig IFACE IP/netmask [up]
ifconfig IFACE IP netmask NETMASK
[root@centos8 ~]#ifconfig eth0 10.0.0.68 netmask 255.255.0.0
[root@centos8 ~]#ifconfig eth0 0.0.0.0/0
[root@centos8 ~]#ifconfig eth0 down
[root@centos8 ~]#ifconfig eth0 up
[root@centos8 ~]#ifconfig eth0:1 172.16.0.8/24
[root@centos8 ~]#ifconfig eth0:1 down
ifconfig -s 统计当前网卡的流量
[root@c7-147 ~]# ifconfig -s
Iface MTU RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg
eth0 1500 92 0 0 0 70 0 0 0 BMRU
eth1 1500 0 0 0 0 0 0 0 0 BMU
lo 65536 2 0 0 0 2 0
[root@c7-137-mariadb-bak ~]# ifconfig -s eth0
Iface MTU RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg
eth0 1500 97595 0 0 0 98686 0 0 0 BMRU
[root@c7-147 ~]# watch -n1 ifconfig -s
[root@c7-137-mariadb-bak ~]# ping -f 10.0.0.147 -s 65507
PING 10.0.0.147 (10.0.0.147) 65507(65535) bytes of data.
..^C
--- 10.0.0.147 ping statistics ---
2142 packets transmitted, 2140 received, 0% packet loss, time 8713ms
4.route
路由表管理命令
路由表主要构成:
Destination: 目标网络ID,表示可以到达的目标网络ID,0.0.0.0/0 表示所有未知网络,又称为默认路由,优先级最低
Genmask:目标网络对应的netmask
Iface: 到达对应网络,应该从当前主机哪个网卡发送出来
Gateway: 到达非直连的网络,将数据发送到临近(下一个)路由器的临近本主机的接口的IP地址,如果
是直连网络,gateway是0.0.0.0
Metric: 开销cost,值越小,路由记录的优先级最高
#任何网络设备都路由表
[root@c7-147 ~]# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 10.0.0.2 0.0.0.0 UG 100 0 0 eth0
10.0.0.0 0.0.0.0 255.255.255.0 U 100 0 0 eth0
添加：route add
route add [-net|-host|default] target [netmask Nm] [gw GW] [[dev] If]
删除：route del
route del [-net|-host] target [gw Gw] [netmask Nm] [[dev] If]
route add -host 192.168.1.3 gw 172.16.0.1 dev eth0
route add -net 192.168.0.0 netmask 255.255.255.0 gw 172.16.0.1 dev eth0
route add -net 192.168.0.0/24 gw 172.16.0.1 dev eth0
route add -net 192.168.8.0/24 dev eth1 metric 200
route add -net 0.0.0.0 netmask 0.0.0.0 gw 172.16.0.1
route add -net 0.0.0.0/0 gw 172.16.0.1 route add default gw 172.16.0.1
route del -host 192.168.1.3
route del -net 192.168.0.0 netmask 255.255.255.0
