一 网络相关文件
[root@serv01 data]# vim/etc/sysconfig/network-scripts/ifcfg-eth0
[root@serv01 data]# cd/etc/sysconfig/network-scripts/
[root@serv01 network-scripts]# ifconfig
#其他的Linux：不一定是eth0，名字不重要，可以修改
[root@serv01 network-scripts]# ls ifcfg-*
ifcfg-eth0 ifcfg-lo
[root@serv01 network-scripts]# catifcfg-eth0
#设备名
DEVICE="eth0"
#MAC地址，全局唯一。一个局域网里两个相同的MAC地址：ARP欺骗
#00:0C:29：厂家ID
#07:DD:3B：厂家定义
HWADDR="00:0C:29:07:DD:3B"
NM_CONTROLLED="yes"
#是否启动生效
ONBOOT="yes"
#IP地址
IPADDR=192.168.1.11
#子网掩码：和IP地址一起计算得到网络号，判断是否属于一个网络段
NETMASK=255.255.255.0
#网关：跨网段传输数据
GATEWAY=192.168.1.11
#网关可以配置到该文件下：network。多张网卡都可以走这个网关。全局配置
#主机名 网关配置
[root@serv01 network-scripts]# vim/etc/sysconfig/network
#IP地址和主机名的对应关系
[root@serv01 network-scripts]# ls/etc/hosts
/etc/hosts
[root@larrywen ~]# vim /etc/hosts
[root@serv01 network-scripts]# tail -n2/etc/hosts
192.168.0.29 up01.host.com
192.168.0.185 up02.host.com
#ping域名，也可以ping通
[root@larrywen ~]# ping up01.host.com
[root@larrywen ~]# ping up02.host.com
#DNS配置
[root@serv01 network-scripts]# vim/etc/resolv.conf
[root@serv01 network-scripts]# cat/etc/resolv.conf
nameserver 8.8.8.8
二 基本网络命令
1.ping命令
#默认一直ping下去，按Ctrl+C结束
[root@larrywen ~]# ping 192.168.1.11
#ping三次
[root@larrywen ~]# ping -c 3 192.168.1.1
#ping三次，并每隔三秒ping一次
[root@serv01 ~]# ping -c 3 -i 3192.168.1.11
#-s：表示可以跟包的大小
[root@serv01 ~]# ping 192.168.1.1 -s 1024
PING 192.168.1.1 (192.168.1.1) 1024(1052)bytes of data.
1032 bytes from 192.168.1.1: icmp_seq=1ttl=64 time=0.130 ms
[root@serv01 ~]# ping --help
#I：指定从哪个设备出去
[root@serv01 ~]# ping -I eth0 192.168.1.11
#
[root@serv01 ~]# ping -I eth1 192.168.1.11
[root@serv02 ~]# ifconfig eth1 172.xxxnetmask=255.255.255.0
2. netstat命令
[root@serv01 ~]# netstat -lanput
#服务的配置文件：端口和服务相对应
[root@serv01 ~]# vim /etc/services
#修改IP地址和子网掩码
[root@serv01 ~]# ifconfig eth1 172.6.13.11netmask 255.255.255.0
#手动修改MAC地址
[root@serv01 ~]# ifconfig eth1 hw ether00:0C:29:07:DD:3C
[root@serv01 ~]# ifconfig eth0
#手动修改MTU
[root@serv01 ~]# ifconfig eth1 mtu 2000
#修改IP地址和子网掩码并取别名，临时有效
[root@serv01 ~]# ifconfig eth1:zk172.6.13.131 netmask 255.255.255.0
[root@serv01 network-scripts]# cpifcfg-eth0 ifcfg-eth1
[root@serv01 network-scripts]# vimifcfg-eth1
[root@serv01 network-scripts]# cpifcfg-eth1 ifcfg-eth1:zk
[root@serv01 network-scripts]# vimifcfg-eth1:zk
#删除
[root@serv01 ~]# ifconfig eth1:zk del172.6.13.131
3.route命令
#路由
[root@serv01 ~]# route -n
#删除route
[root@serv02 ~]# route del -net 169.254.0.0netmask 255.255.0.0 dev eth0
[root@serv02 ~]# route del -net 169.254.0.0netmask 255.255.0.0 dev eth1
[root@serv02 ~]# service iptables stop
[root@serv02 ~]# setenforce 0
4.ip命令
#命令强大，不通用
[root@serv02~]# ip address
#这些简写都可以
[root@serv02~]# ip addr
[root@serv02~]# ip add
[root@serv02~]# ip ad
[root@serv02 ~]# ip a
#link：修改网卡的基本信息
[root@serv02 ~]# ip link set eth1 mtu 2000
[root@serv02 ~]# ip link
[root@serv02 ~]# ip link show
[root@serv02 ~]# ip link list
[root@serv02 ~]# ip link set eth1 qlen 1500
[root@serv02 ~]# ip link
#ifconfig 无法改网卡名字
[root@serv02 ~]# ip link set eth1 namezhink
[root@serv02 ~]# ip link help
#开启网络
[root@serv02 ~]# ip link set eth1 up
#关闭网络
[root@serv02 ~]# ip link set eth1 down
[root@serv02 ~]# ip address add172.16.1.12/255.255.255.0 broadcast 172.16.1.255 dev eth1
[root@serv02 ~]# ip address add172.16.1.12/255.255.255.0 brd 172.16.1.255 dev eth1
#设置IP
[root@serv03 ~]# ip address add172.16.1.13/255.255.255.0 brd 172.16.1.255 dev eth1
[root@serv03 ~]# ip link
[root@serv03 ~]# ip link set eth1 up
[root@serv03 ~]# ip link
#删除IP 地址
[root@serv03 ~]# ip addr del 172.16.1.15/24dev eth1
#查看路由
[root@serv03 ~]# ip route
172.16.1.0/24 dev eth0 proto kernel scope link src 172.16.1.13
172.16.1.0/24 dev eth1 proto kernel scope link src 172.16.1.14
#添加默认路由
[root@serv02 ~]# ip route add default via192.168.1.12 dev eth0
[root@serv02 ~]# ip route
[root@serv02 ~]# route -n
#删除默认路由
[root@serv02 ~]# ip route del default via192.168.1.12 dev eth0
[root@serv02 ~]# ip route
192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.12
172.16.1.0/24 dev eth1 proto kernel scope link src 172.16.1.12
169.254.0.0/16 dev eth0 scope link metric 1003
[root@serv02 ~]# ip route help
三 实验一（route命令实现）
3.1小实验
3.2目标
client01（192.168.1.11）可以ping通client2（10.10.1.14）
[root@client01 ~]# ping 10.10.1.14
connect: Network is unreachable
3.3 准备工作
3.3.1.关闭防火墙和SELINUX
[root@client01 ~]# service iptables stop
[root@client01 ~]# setenforce 0
3.3.2.虚拟机配置
Client01：使用Vmnet1
Serv02：使用Vmnet1、Vmnet2
Serv03：使用Vmnet2、Vmnet3
Client02：使用Vmnet3
3.3.3.配置IP，并测试相邻机器的IP地址是否能ping通
#第一台机器
[root@client01 ~]# ifconfig eth0192.168.1.11 netmask 255.255.255.0
[root@client01 ~]# ping 192.168.1.12
[root@client01 ~]# ping 192.168.1.1
#第二台机器
[root@serv02 ~]# ifconfig eth0 192.168.1.12netmask 255.255.255.0
[root@serv02 ~]# ifconfig eth1 172.16.1.12netmask 255.255.255.0
[root@serv02 ~]# ping 192.168.1.11
[root@serv02 ~]# ping 192.168.1.1
#第三台机器
[root@serv03 ~]# ifconfig eth0 172.16.1.13netmask 255.255.255.0
[root@serv03 ~]# ifconfig eth1 10.10.1.13netmask 255.255.255.0
[root@serv03 ~]# ping 172.16.1.12
[root@serv03 ~]# ping 172.16.1.1
#第四台机器
[root@client02 ~]# ifconfig eth0 10.10.1.14netmask 255.255.255.0
[root@client02 ~]# ping 10.10.1.14
[root@client02 ~]# ping 10.10.1.1
3.4.解决
#第一台机器
#添加默认网关
[root@client01 ~]# route add default gw192.168.1.12
#修改sysctl.conf文件，net.ipv4.ip_forward改为1，然后执行sysctl-p让修改生效
[root@serv02 ~]# vi /etc/sysctl.conf
[root@serv02 ~]# sysctl -p
[root@client01 ~]# sed "7p"/etc/sysctl.conf -n
net.ipv4.ip_forward = 1
#第二台机器
#添加路由，指定10.10.1.0网段的IP从172.16.1.13出去
[root@serv02 ~]# route add -net 10.10.1.0netmask 255.255.255.0 gw 172.16.1.13
#修改sysctl.conf文件，net.ipv4.ip_forward改为1，然后执行sysctl-p让修改生效
[root@serv02 ~]# vi /etc/sysctl.conf
[root@serv02 ~]# sysctl -p
[root@serv02 ~]# sed "7p"/etc/sysctl.conf -n
net.ipv4.ip_forward = 1
#第三台机器
#添加路由，指定192.168.1.0网段的IP从172.16.1.12出去
[root@serv03 /]# route add -net 192.168.1.0netmask 255.255.255.0 gw 172.16.1.12
#修改sysctl.conf文件，net.ipv4.ip_forward改为1，然后执行sysctl-p让修改生效
[root@serv02 ~]# vi /etc/sysctl.conf
[root@serv02 ~]# sysctl -p
[root@serv03 /]# sed "7p"/etc/sysctl.conf -n
net.ipv4.ip_forward = 1
#第四台机器
[root@client02 ~]# route add default gw10.10.1.13
#修改sysctl.conf文件，net.ipv4.ip_forward改为1，然后执行sysctl-p让修改生效
[root@serv02 ~]# vi /etc/sysctl.conf
[root@serv02 ~]# sysctl -p
[root@client02 ~]# sed "7p"/etc/sysctl.conf -n
net.ipv4.ip_forward = 1
3.5效果
#客户机1ping客户机2
[root@client01 ~]# ping 10.10.1.14
PING 10.10.1.14 (10.10.1.14) 56(84) bytesof data.
64 bytes from 10.10.1.14: icmp_seq=1 ttl=62time=1.84 ms
64 bytes from 10.10.1.14: icmp_seq=2 ttl=62time=0.856 ms
64 bytes from 10.10.1.14: icmp_seq=3 ttl=62time=1.13 ms
64 bytes from 10.10.1.14: icmp_seq=4 ttl=62time=0.805 ms
64 bytes from 10.10.1.14: icmp_seq=5 ttl=62time=0.866 ms
64 bytes from 10.10.1.14: icmp_seq=6 ttl=62time=0.730 ms
64 bytes from 10.10.1.14: icmp_seq=7 ttl=62time=0.596 ms
64 bytes from 10.10.1.14: icmp_seq=8 ttl=62time=0.788 ms
64 bytes from 10.10.1.14: icmp_seq=9 ttl=62time=0.741 m
#路由器1抓取来自客户机1的包
[root@serv02 ~]# tcpdump -i eth0 host192.168.1.11
tcpdump: verbose output suppressed, use -vor -vv for full protocol decode
listening on eth0, link-type EN10MB(Ethernet), capture size 65535 bytes
01:10:02.177598 IP 192.168.1.11 >10.10.1.14: ICMP echo request, id 26629, seq 65, length 64
01:10:02.178496 IP 10.10.1.14 >192.168.1.11: ICMP echo reply, id 26629, seq 65, length 64
01:10:02.179861 IP 192.168.1.1.51524 >192.168.1.11.ssh: Flags [.], ack 1140604063, win 472, options [nop,nop,TS val30797133 ecr 5038478], length 0
01:10:02.179882 IP 192.168.1.11.ssh > 192.168.1.1.51524:Flags [P.], seq 4294967201:1, ack 0, win 429, options [nop,nop,TS val 5038478ecr 30796131], length 96
#路由器2抓取来自客户机1的包
[root@serv03 /]# tcpdump -i eth0 host 192.168.1.11
tcpdump: verbose output suppressed, use -vor -vv for full protocol decode
listening on eth0, link-type EN10MB(Ethernet), capture size 65535 bytes
01:10:18.038232 IP 192.168.1.11 >10.10.1.14: ICMP echo request, id 26629, seq 81, length 64
01:10:18.038655 IP 10.10.1.14 >192.168.1.11: ICMP echo reply, id 26629, seq 81, length 64
01:10:19.039708 IP 192.168.1.11 >10.10.1.14: ICMP echo request, id 26629, seq 82, length 64
01:10:19.040050 IP 10.10.1.14 >192.168.1.11: ICMP echo reply, id 26629, seq 82, length 64
#客户机2抓取来自客户机1的包
[root@client02 ~]# tcpdump -i eth0 host192.168.1.11
tcpdump: verbose output suppressed, use -vor -vv for full protocol decode
listening on eth0, link-type EN10MB(Ethernet), capture size 65535 bytes
01:10:31.341271 IP 192.168.1.11 >10.10.1.14: ICMP echo request, id 26629, seq 94, length 64
01:10:31.341298 IP 10.10.1.14 >192.168.1.11: ICMP echo reply, id 26629, seq 94, length 64
01:10:32.341282 IP 192.168.1.11 >10.10.1.14: ICMP echo request, id 26629, seq 95, length 64
01:10:32.341310 IP 10.10.1.14 >192.168.1.11: ICMP echo reply, id 26629, seq 95, length 64
#客户机2ping客户机1
[root@client02 ~]# ping 192.168.1.11
PING 192.168.1.11 (192.168.1.11) 56(84)bytes of data.
64 bytes from 192.168.1.11: icmp_seq=1ttl=62 time=0.752 ms
64 bytes from 192.168.1.11: icmp_seq=2ttl=62 time=0.951 ms
64 bytes from 192.168.1.11: icmp_seq=3ttl=62 time=0.604 ms
64 bytes from 192.168.1.11: icmp_seq=4ttl=62 time=1.02 ms
#路由器1抓取来自客户机2的包
[root@serv02 ~]# tcpdump -i eth0 host10.10.1.14
tcpdump: verbose output suppressed, use -vor -vv for full protocol decode
listening on eth0, link-type EN10MB(Ethernet), capture size 65535 bytes
01:11:36.589348 IP 10.10.1.14 >192.168.1.11: ICMP echo request, id 51205, seq 44, length 64
01:11:36.589971 IP 192.168.1.11 >10.10.1.14: ICMP echo reply, id 51205, seq 44, length 64
01:11:37.590849 IP 10.10.1.14 >192.168.1.11: ICMP echo request, id 51205, seq 45, length 64
01:11:37.591093 IP 192.168.1.11 >10.10.1.14: ICMP echo reply, id 51205, seq 45, length 64
#路由器2抓取来自客户机2的包
[root@serv03 /]# tcpdump -i eth0 host 10.10.1.14
tcpdump: verbose output suppressed, use -vor -vv for full protocol decode
listening on eth0, link-type EN10MB(Ethernet), capture size 65535 bytes
01:11:20.425712 IP 10.10.1.14 >192.168.1.11: ICMP echo request, id 51205, seq 28, length 64
01:11:20.426316 IP 192.168.1.11 >10.10.1.14: ICMP echo reply, id 51205, seq 28, length 64
01:11:21.426282 IP 10.10.1.14 >192.168.1.11: ICMP echo request, id 51205, seq 29, length 64
01:11:21.426769 IP 192.168.1.11 >10.10.1.14: ICMP echo reply, id 51205, seq 29, length 64
01:11:22.426792 IP 10.10.1.14 >192.168.1.11: ICMP echo request, id 51205, seq 30, length 64
01:11:22.427346 IP 192.168.1.11 >10.10.1.14: ICMP echo reply, id 51205, seq 30, length 64
#客户机1抓取来自客户机2的包
[root@client01 ~]# tcpdump -i eth0 host10.10.1.14
tcpdump: verbose output suppressed, use -vor -vv for full protocol decode
listening on eth0, link-type EN10MB(Ethernet), capture size 65535 bytes
01:12:27.549172 IP 10.10.1.14 >192.168.1.11: ICMP echo request, id 51205, seq 95, length 64
01:12:27.549198 IP 192.168.1.11 >10.10.1.14: ICMP echo reply, id 51205, seq 95, length 64
01:12:28.549233 IP 10.10.1.14 >192.168.1.11: ICMP echo request, id 51205, seq 96, length 64
01:12:28.549259 IP 192.168.1.11 >10.10.1.14: ICMP echo reply, id 51205, seq 96, length 64
四 实验----ip命令实现
#准备条件
[root@client01 ~]# service iptables stop
[root@client01 ~]# setenforce 0
[root@client01 ~]# chkconfig iptables off
[root@client01 ~]# chkconfig ip6tables off
#第一台机器的配置
[root@client01 ~]# ip route add default via192.168.1.12 dev eth0
[root@client01 ~]# route -n
[root@client01 ~]# sysctl -wnet.ipv4.ip_forward=1
net.ipv4.ip_forward = 1
#第二台机器的配置
[root@serv02 ~]# ip route add10.10.1.0/255.255.255.0 via 172.16.1.13 dev eth1
[root@serv02 ~]# ip route
[root@serv02 ~]# sysctl -w net.ipv4.ip_forward=1
net.ipv4.ip_forward = 1
#第三台机器
[root@serv03 ~]# ip route add192.168.1.0/255.255.255.0 via 172.16.1.12 dev eth0
[root@serv03 ~]# route -n
[root@serv03 ~]# sysctl -wnet.ipv4.ip_forward=1
net.ipv4.ip_forward = 1
#第四台机器
[root@client02 ~]# sysctl -wnet.ipv4.ip_forward=1
net.ipv4.ip_forward = 1
[root@client02 ~]# cat/proc/sys/net/ipv4/ip_forward＝1
[root@client02 ~]# ip route add default via10.10.1.13 dev eth0
[root@client02 ~]# route -n
作者：justdb
