Linux网络配置

PlayerL 2020-06-03

一、网络地址计算:

二进制转换;

查看是否为同一个网段,需要根据ip地址和掩码一起决定。  二进制转换这里不做说明

根据ip和掩码来区分,如10.0.7.10/20和10.0.14.11/20是同一个网段,但是10.0.7.10/21和10.0.14.11/21就是不同网段

二、管理以太网连接

网络接口有序的命令为:eth0,eth1,等

  。可以给一个设备作为别名配置多个地址

  。别名以eth0:1,eth0:2,等命令.

  。别名可以看成子接口

使用ifcofnig [ethX]查看接口配置 ;lo逻辑接口,只在自己电脑有效。

使用ifup ethX启动接口

使用ifdown ethX禁用接口

网络配置文件其他全局网络设置

  全局设置/etc/sysconfig/network

    。很多参数可以由DHCP提供

    。GATEWAY可以被ifcfg配置文件取代

      

NETWORKING=yes
HOSTNAME=service1.example.com
GATEWAY=192.168.2.254

虚拟机1:

[ ~]# ip route show    //查看本机ip列表
192.168.6.0/24 dev eth0  proto kernel  scope link  src 192.168.6.128 
169.254.0.0/16 dev eth0  scope link  metric 1002 
default via 192.168.6.2 dev eth0 
[ ~]# ip addr add 10.0.7.10/10 dev eth0:testing  添加ip地址到网卡
[ ~]# ip route show    //查看ip列表
192.168.6.0/24 dev eth0  proto kernel  scope link  src 192.168.6.128 
169.254.0.0/16 dev eth0  scope link  metric 1002 
10.0.0.0/10 dev eth0  proto kernel  scope link  src 10.0.7.10 
default via 192.168.6.2 dev eth0

虚拟机2:

[ ~]# ip route show
192.168.6.0/24 dev eth0  proto kernel  scope link  src 192.168.6.129 
169.254.0.0/16 dev eth0  scope link  metric 1002 
default via 192.168.6.2 dev eth0 
[ ~]# ip addr del 10.0.0.128/24 dev eth0    //删除网卡
RTNETLINK answers: Cannot assign requested address
[ ~]# ip addr add 10.0.14.11/20 dev eth0:testing    //添加网卡
[ ~]# ping 10.0.14.11 -c2    //ping两次包
PING 10.0.14.11 (10.0.14.11) 56(84) bytes of data.
64 bytes from 10.0.14.11: icmp_seq=1 ttl=64 time=0.030 ms
64 bytes from 10.0.14.11: icmp_seq=2 ttl=64 time=0.036 ms

--- 10.0.14.11 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1000ms
rtt min/avg/max/mdev = 0.030/0.033/0.036/0.003 ms
[ ~]# ping 10.0.7.10 -c2
PING 10.0.7.10 (10.0.7.10) 56(84) bytes of data.
64 bytes from 10.0.7.10: icmp_seq=1 ttl=64 time=0.781 ms
64 bytes from 10.0.7.10: icmp_seq=2 ttl=64 time=0.456 ms

--- 10.0.7.10 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1000ms
rtt min/avg/max/mdev = 0.456/0.618/0.781/0.164 ms
[ ~]# ip addr del 10.0.14.11/20 dev eth0:testing
[ ~]# ip addr add 10.0.14.11/21 dev eth0:testing
[ ~]# ip route
192.168.6.0/24 dev eth0  proto kernel  scope link  src 192.168.6.129 
10.0.8.0/21 dev eth0  proto kernel  scope link  src 10.0.14.11 
169.254.0.0/16 dev eth0  scope link  metric 1002 
default via 192.168.6.2 dev eth0 
[ ~]# ping 10.0.0.7 -c2
PING 10.0.0.7 (10.0.0.7) 56(84) bytes of data.
^C
--- 10.0.0.7 ping statistics ---
2 packets transmitted, 0 received, 100% packet loss, time 2008ms
使用别名的方式配置网络:[ ~]# ifconfig eth0:tech 10.0.0.128/24
[ ~]# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:0C:29:20:00:C1  
          inet addr:192.168.6.128  Bcast:192.168.6.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe20:c1/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:48162 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1750 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:2954753 (2.8 MiB)  TX bytes:124210 (121.2 KiB)

eth0:tech Link encap:Ethernet  HWaddr 00:0C:29:20:00:C1  
          inet addr:10.0.0.128  Bcast:10.0.0.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

使用ip link排查网络

#ip link help

#ip link show查看端口是否插入网线:

[ ~]# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:20:00:c1 brd ff:ff:ff:ff:ff:ff

#ip addr help

#ip add show  

[ ~]# ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:20:00:c1 brd ff:ff:ff:ff:ff:ff
    inet 192.168.6.128/24 brd 192.168.6.255 scope global eth0
    inet 10.0.7.10/10 scope global eth0
    inet 10.0.0.128/24 brd 10.0.0.255 scope global eth0:tech
    inet6 fe80::20c:29ff:fe20:c1/64 scope link 
       valid_lft forever preferred_lft forever
[ ~]# ip addr del 10.0.7.10/10 dev eth0
[ ~]# ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:20:00:c1 brd ff:ff:ff:ff:ff:ff
    inet 192.168.6.128/24 brd 192.168.6.255 scope global eth0
    inet 10.0.0.128/24 brd 10.0.0.255 scope global eth0:tech
    inet6 fe80::20c:29ff:fe20:c1/64 scope link 
       valid_lft forever preferred_lft forever
[ ~]# ip del 10.0.0.128/24 dev eth0
Object "del" is unknown, try "ip help".
[ ~]# ip addr  del 10.0.0.128/24 dev eth0

 选择别名的方式通过ifconfig是看不了ip addr配置网络信息的。

ifconfig配置的方式可以通过ifconfig命令看到

以上配置方式均为临时配置方式。如果需要永久生效可以通过【图形网络配置system-config-network】配置

系统->管理->网络

  。激活/禁用接口

  。设置IP地址/DHCP

  。修改DNS配置

  。修改网关地址

网络配置文件以太网设备

设备配置以文本文件保存/etc/sysconfig/network-scripts/ifcfg-ethX

所有的选项列在/usr/share/doc/initscripts-*/sysconfig.txt

Linux网络配置

 BOOTPROTO是DHCP的引导协议 

重启网络:

[ ~]# /etc/init.d/network restart
正在关闭接口 eth0:                                        [确定]
关闭环回接口:                                             [确定]
弹出环回接口:                                             [确定]
弹出界面 eth0:                                            [确定]  

网络配置文件其他全局网络设置

全局设置/etc/sysconfig/network配置网关

  。很多参数可以由DHCP提供

  。GATEWAY可以被ifcfg配置文件取代

    NETWORKING=yes

    HOSTNAME=server1.example.com

    GATEWAY=192.168.2.254

网关:

[ ~]# ip route get 192.14.21.1  //使用ip route get ip地址查找当前服务器配置的缺省网关地址为192.168.6.2
192.14.21.1 via 192.168.6.2 dev eth0  src 192.168.6.128 
    cache  mtu 1500 advmss 1460 hoplimit 64
[ ~]# ip route get 192.14.48.5
192.14.48.5 via 192.168.6.2 dev eth0  src 192.168.6.128 
    cache  mtu 1500 advmss 1460 hoplimit 64

临时改动网关,也就是服务器下一跳地址:

[ ~]# ip route show
192.168.6.0/24 dev eth0  proto kernel  scope link  src 192.168.6.128 
169.254.0.0/16 dev eth0  scope link  metric 1002 
default via 192.168.6.2 dev eth0 
[ ~]# ip route replace default via 192.168.6.254    //替换下一跳网关或者路由
[ ~]# ip route show
192.168.6.0/24 dev eth0  proto kernel  scope link  src 192.168.6.128 
169.254.0.0/16 dev eth0  scope link  metric 1002 
default via 192.168.6.254 dev eth0

[ ~]# ip route del default     //删除默认路由
[ ~]# ip route show
192.168.6.0/24 dev eth0 proto kernel scope link src 192.168.6.128
169.254.0.0/16 dev eth0 scope link metric 1002

[ ~]# ip route add 0.0.0.0/0 via 192.168.6.2    //添加默认路由
[ ~]# ip route show
192.168.6.0/24 dev eth0 proto kernel scope link src 192.168.6.128
169.254.0.0/16 dev eth0 scope link metric 1002
default via 192.168.6.2 dev eth0

网关只有一个。所以不要在ifcfg-ethX中配置GATEWAY,不然不好找到对应的GATEWAY。尽量在全局配置GATEWAY

DNS网络配置文件

。域名服务提供了主机名到网络地址的转换

。服务器地址可以通过DHCP或者/etc/resolv.conf指定

search example.com cracker.org

nameserver 192.168.6.254

nameserver 192.168.6.254  

[ ~]# nslookup example.com       //解析域名看看对应的IP
Server:		192.168.6.2
Address:	192.168.6.2#53

Non-authoritative answer:
Name:	example.com
Address: 93.184.216.34

[ ~]# cat /etc/resolv.conf

[ ~]# cat /etc/services | grep domain
domain 53/tcp # name-domain server
domain 53/udp
domaintime 9909/tcp # domaintime
domaintime 9909/udp # domaintime

DNS查询命令:

host ip方向解析域名

host 域名解析ip

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