ip 网络层协议
ip地址 点分十进制分为4段，范围 0-255
ip分类
A 占据1段，最左侧一段第一位固定为0
0 000 0000 - 0 111 1111
0 - 127：其中0为网络，127 本地主机内部通信。
网络数: 2^7-2=126个
每个网络中的主机数: 2^24=16777216 (1677736)
默认子网掩码: 255.0.0.0
私网地址: 10.0.0.0/8 (8:网络段全为1，有8位)
B 占据2段，最左侧一段第一位固定为10
10 00 0000 - 10 11 1111
128 - 191
网络数:2^(6+8)=2^14=16384个
每个网络中的主机数: 2^16=65536
默认子网掩码:255.255.0.0
私网地址: 172.16.0.0/16 - 172.31.0.0/16 (网络变化位第2位)
C 占据3段，最左侧一段第一位固定为110
110 0 0000 - 110 1 1111
192 - 223
网络数:2^(5+8+8)=2^21=2097152个
每个网络中的主机数: 2^16=65536
默认子网掩码:255.255.255.0
私网地址: 192.168.0.0/24 - 192.168.255.0/24 (网络变化位第3位)
D 占据4段，最左侧一段第一位固定为1110
1110 0000 - 1110 1111
224 - 239
网络数:2^(4+8+8+8)=2^28=268435456个
E 240 - 255
子网掩码：计算ip地址所在的网络
网络相同，本地通信
网络不同，跨网络通信借助路由器(网络层、数据链路层、物理层)
例如：IP:145.239.123.0 MASK 224.239.234.123 网络？
IP地址的二进制 1001 0001 . 1110 1111 . 0111 1011 . 0000 0000
MASK的二进制 1110 0000 . 1110 1111 . 1110 1010 . 0111 1011
网络的二进制 1000 0000 . 1110 1111 . 0110 1010 . 0000 0000
网络地址: 128.239.106.0
路由配置：在未梢网络中，路由器一般指的是默认网关
主机路由:目标是主机
网络路由:目标是网络
默认网关：目标无论为主机或是网络
路由选择：选择匹配精度越高，匹配结果越少
主机路由 > 网络路由 > 默认网关
0.0.0.0
网关: 到达本地的路由信息
目标: 到达任意网络或主机的路由信息
网络接口命名
centos6 根据MAC，eth[0,1,2,...] 在重启后可能会改变
centos7 根据插口/根据PCI-E总线的槽 ，重启后不变
网络属性配置: 让CentOS主机能够接入至网络中
1、配置IP
2、配置路由ROUTE
3、配置DNS服务
配置方式
1、命令行配置: 配置在内核中的内存地址中，下次重启失效
1）ifcfg家族,ip家族
2）nmcli
2、编辑配置文件配置: 永久有效
/etc/sysconfig/network-scripts/ifcfg-NAME
/etc/sysconfig/network-scripts/route-NAME
3、图形接口配置
system-config-network-tui(setup)
nmtui
命令行配置
ifcfg家族：ifconfig,route,netstat
ip家族：ip,ss
特点
1、netstat和ss使用基本相似
1）ss响应比netstat快
2）ss选项 -m,memory。 -o 。 state TCP-STATE [EXPRESSION]
2、ip和ifcfg家族，实现的功能查看IP，设置IP，查看ROUTE,设定ROUTE.基本相似。
1）ip比ifcfg多出 同 yum 比rpm命令多出：查看时支持Glob通配字符的使用，
ip支持过滤功能 scope SCOPE_NA, label LABEL , dev NAME , to PREFIX ，primary or secondary
3、ip命令不修改网卡地址，ifconfig修改网卡地址。ip命令给网卡添加辅助地址，可有别名
1.1、命令行配置
ifcfg家庭：ifconfig,route,netstat
ifconfig命令
网络属性显示和配置
ifconfig [options...] [interface] [up|down]
-a 显示所有接口
[-]promise 启用混杂模式
metric N 到达目标的开销值
ifconfig interface address [up|down]
address: ip/mask 或 ip netmask MASK
例如 1.1.1.1/8或1.1.1.1 netmask 255.0.0.0
# ifconfig IFACE address
# ifconfig IFACE address up | down
route命令
route -n 显示内核中的路由表
Destination Gateway Genmask Flags Metric Ref Use Iface
Destination 到达的目标：主机、网络、默认，最终到达主机
Gateway 网关
Genmask 目标的掩码
Flags 标识位
Metric 开销，到达目标的开销
Iface 报文离开本主机经过的网卡
route add|del -host|-net address gw GW dev interface
添加:route add -host|-net address gw GW dev interface
添加主机路由:
route add -host ip/32 gw GW dev interface
route add -host ip netmask MASK gw GW dev interface
添加网络路由:
route add -net ip/mask gw GW dev interface
route add -net ip netmask MASK gw GW dev interface
删除: route del -host|-net address
删除主机路由
route del -host address
删除网络路由
route del -net address
默认路由: -net 0.0.0.0 mask 0.0.0.0
route add|del default gw GW dev IFACE
dig命令
dig -t A FQDN
dig -x IP
host命令
host -t A FQDN
host -t PTR IP
netstat命令
1、network connection:
netstat OPTIONS
-t tcp连接
-u udp连接
-w raw裸套接字
-n numeric不反解IP
-a all所有t,u,..
-l listen监听，等待别人访问
-p program和Pid
-e user和inode
2、routing tables:
netstat OPTIONS
-r 显示内核中的路由表
-n numeric
3、interface statistics
netstat OPTIONS
-i 显示所有接口
-I<dev> 显示指定接口
1、查看IP: ifconfig interface
1）查看激活
[root@localhost ~]# ifconfig eth0 lo
2）查看所有
[root@localhost ~]# ifconfig -a eth0 lo
3）查看指定
[root@localhost ~]# ifconfig lo lo
2、配置IP: ifconfig interface { ip/mask | ip netmask MASK }
[root@localhost ~]# ifconfig eth0 172.16.100.1/16 [root@localhost ~]# ifconfig eth0 172.16.100.1 netmask 255.255.0.0
3、查看路由: route -n
[root@localhost ~]# netstat -rn [root@localhost ~]# route -n
4、配置路由: route add -host | -net { ip/mask | ip netmask MASK} gw GW dev interface
[root@localhost ~]# route add -host 172.16.100.9/32 gw 192.168.3.1 dev eth0 [root@localhost ~]# route add -host 172.16.100.9 netmask 255.255.255.255 gw 192.168.3.1 dev eth0 [root@localhost ~]# route add -host 172.16.100.9 gw 192.168.3.1 dev eth0 [root@localhost ~]# route add -net 0.0.0.0/0 gw 192.168.3.1 dev eth0 [root@localhost ~]# route add default gw 192.168.3.1 dev eth0
5、配置DNS: /etc/resolv.conf
nameserver DNS_SERVER_IP1
nameserver DNS_SERVER_IP2
nameserver DNS_SERVER_IP3
测试DNS服务器
正解: FQDN -->IP
dig -t A FQDN
host -t A FQDN
反解: IP --> FQDN
dig -x IP
host -t PTR IP
[root@localhost ~]# vim /etc/resolv.conf nameserver 192.168.3.1 nameserver 8.8.8.8 nameserver 4.4.4.4
6、网络状态查看: netstat option , options: -t tcp,-u udp,-r raw,-n numeric,-a all,-l listen,-p program,-e extend,
# netstat -tan # netstat -uan # netstat -tnl # netstat -unl（无状态） # netstat -rnl -ran # netstat -tunlp # netstat -tunlpe
裸套接字：不经过传输层，由应用层直接调用IP实现数据传输
numeric: netstat命令默认将Ip反解为字母，-n选项关闭此特性
extend: user,inode扩展信息
program:PID和名字
7、查看内核中的路由表: route -nr
# route -rn
8、查看接口数据: netstat -i查看所有接口数据 , netstat -I<dev>查看由dev指定接口的数据
# netstat -i # netsta -Ieth0
Iface MTU RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg
eth0 1500 1837695 0 0 0 1160482 0 0 0 BMRU
lo 65536 20083 0 0 0 20083 0 0 0 LRU
RX-OK receive？接收时正确数据包
RX-ERR 错误
RX-DRP DROPPED dropped received packets (due to memory lack ?) 丢弃接收的包，由于内存不足吗？
RX-OVR packets that we were unable to receive that fast way. 不能快速接收的包
TX-OK transport?
TX-ERR
TX-DRP
TX-OVR
Flg flag?
1.2、命令行配置：
ip家庭：ip,ss
ip命令
显示ip命令由哪个程序包生成
1、rpm -qf `which --skip-alias ip`
[root@localhost ~]# rpm -qf `which --skip-alias ip` iproute-2.6.32-54.el6.i686
2、rpm -q --whatprovides /sbin/ip
[root@localhost ~]# rpm -q --whatprovides `which --skip-alias ip` iproute-2.6.32-54.el6.i686
3、yum whatprovides /sbin/ip
[root@localhost ~]# yum whatprovides `which --skip-alias ip` Failed to set locale, defaulting to C ??????fastestmirror, security Loading mirror speeds from cached hostfile * base: mirrors.btte.net * extras: mirrors.zju.edu.cn * updates: mirrors.zju.edu.cn iproute-2.6.32-54.el6.i686 : Advanced IP routing and network device configuration tools Repo : base ?????: Filename : /sbin/ip iproute-2.6.32-54.el6.i686 : Advanced IP routing and network device configuration tools Repo : installed ?????: Other : ???????/sbin/ip
4、dnf whatprovides /sbin/ip
[root@izpo45bh60h6bsz ~]# dnf whatprovides /bin/bash Using metadata from Fri Aug 18 16:46:51 2017 bash-4.2.46-20.el7_2.x86_64 : The GNU Bourne Again shell 仓库 ：@System bash-4.2.46-20.el7_2.x86_64 : The GNU Bourne Again shell 仓库 ：base
显示程序包生成的内容
rpm -q -l iproute
/sbin/bridge /sbin/cbq /sbin/ifcfg /sbin/ip /sbin/rtmon /sbin/tc /usr/lib/tc /usr/lib/tc/m_xt.so /usr/sbin/arpd /usr/sbin/lnstat /usr/sbin/nstat /usr/sbin/rtacct /usr/sbin/ss
获取命令帮助: ip OBJECT help
语法格式: ip OBJECT
OBJECT: link , addr , route
+++++++
ip link SUB_CMD 管理网络设备
SUB_CMD:
set ，设备启动或禁止
show , 显示设备的属性
获取帮助: ip link help
ip link show [ dev IFACE | up ]
显示所有接口: ip link show
显示指定接口: ip link show dev IFACE
显示处于激活状态的接口: ip link show up
接口状态描述
eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff scope global
1）网卡名: eth0
2）设备支持的功能: <BROADCAST,MULTICAST,UP,LOWER_UP>
3) 设备的特性: mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
4) 设备的地址: link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff
BROADCAST: 广播
MULTICAST: 多播
UP: 当前网卡的状态
mtu 1500: 以太网的MTU值最大为1500字节
qdisc pfifo_fast :流控算法或实现的机制
state UNKNOWN 网卡当前的状态
qlen 1000 队列长度
link/ether 00:0c:29:cf:cd:ae 当前网卡的MAC地址
brd ff:ff:ff:ff:ff:ff 当前网卡的广播地址
ip link set dev IFACE [ up | down ]
IFACE 网卡接口名
激活接口: ip link set dev IFACE up
关闭接口: ip link set dev IFACE down
使用ip link 管理设备示例
1、显示所有接口
[root@localhost ~]# ip link show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 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 UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff
2、显示指定设备
[root@localhost ~]# ip link show dev eth0 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff
3、显示启用的设备
[root@localhost ~]# ip link show up 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 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 UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff
4、禁用某个设备
[root@localhost ~]# ip link set dev lo down ##显示启用的设备 [root@localhost ~]# ip link show up 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff ##显示所有的设备 [root@localhost ~]# ip link show 1: lo: <LOOPBACK> mtu 65536 qdisc noqueue state DOWN 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 UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff
state DOWN
5、激活某个设备
[root@localhost ~]# ip link set dev lo up [root@localhost ~]# ip link show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 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 UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff
UP
+++++++
ip addr SUB_CMD 管理接口地址
SUB_CMD:
add | del 添加或删除地址
show | flush 显示或删除地址,支持显示的过滤功能
获取帮助: ip addr help
ip addr add | del address dev IFACE [ broadcast ADDRESS ] [ label LABEL ] [ scope {*global*|site|link|host} ]
默认在网卡在添加多个地址，并非修改网卡地址
broadcast ADDRESS 添加地址时设定广播地址
label LABEL 添加地址，给出别名
scope SCOPE 设定级别
address: ip/mask
ip addr show|flush [ dev IFACE ] [ scope {global|site|link|host} ] [ to PREFIX ] [ label PATTERN ] [ primary | secondary ] 显示、查询 或清空
global默认。
link 只响应ping此接口的主机 。
host 只响应当前主机Ping对此接口。
ip addr 管理接口地址使用示例
1、设定接口辅助地址
# ip addr add 172.16.100.9/16
2、以别名添加接口辅助地址
[root@localhost ~]# ip addr add 172.16.100.1/16 dev eth0 label eth0:12 [root@localhost ~]# ip addr show label eth0:12 inet 172.16.100.1/16 scope global eth0:12
3、以级别添加接口辅助地址
[root@localhost ~]# ip addr add 172.16.100.100/32 dev eth0 scope host [root@localhost ~]# ip addr show scope host 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 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 UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff inet 172.16.100.100/32 scope host eth0
4、显示接口的地址
1）、显示所有 [root@localhost ~]# ip addr show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 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 UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff inet 192.168.1.103/24 brd 192.168.1.255 scope global eth0 2）、显示单个 [root@localhost ~]# ip addr show dev eth0 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff inet 192.168.1.103/24 brd 192.168.1.255 scope global eth0
5、显示别名的地址
[root@localhost ~]# ip addr add 172.16.100.1/16 dev eth0 label eth0:12 [root@localhost ~]# ip addr show label eth0:12 inet 172.16.100.1/16 scope global eth0:12
6、显示前缀的地址
[root@localhost ~]# ip addr show to 172.16.100.1 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000 inet 172.16.100.1/16 scope global eth0:12
7、显示主地址
##显示所有地址 [root@localhost ~]# ip addr show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 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 UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff inet 172.16.100.100/32 scope host eth0 inet 192.168.1.103/24 brd 192.168.1.255 scope global eth0 inet 172.16.100.1/16 scope global eth0:12 ##显示主地址 [root@localhost ~]# ip addr show scope global 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 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 UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff inet 192.168.1.103/24 brd 192.168.1.255 scope global eth0 inet 172.16.100.1/16 scope global eth0:12 ##显示primary [root@localhost ~]# ip addr show primary 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 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 UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff inet 172.16.100.100/32 scope host eth0 inet 192.168.1.103/24 brd 192.168.1.255 scope global eth0 inet 172.16.100.1/16 scope global eth0:12 ##显示secondary [root@localhost ~]# ip addr show secondary 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 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 UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff
8、清空设备的地址
[root@localhost ~]# ip addr flush dev lo [root@localhost ~]# ip addr flush dev eth0
9、清空别名的地址
[root@localhost ~]# ip addr show label eth0:0 inet 172.16.100.1/16 scope global eth0:0 [root@localhost ~]# ip addr flush label eth0:0 [root@localhost ~]# ip addr show label eth0:0 [root@localhost ~]#
10、清空主地址
# ip addr flush primary Connection closed by foreign host. Disconnected from remote host(192.168.1.103:22) at 19:06:58. Type `help' to learn how to use Xshell prompt. [c:\~]$
11、清空所有从地址
[root@localhost ~]# ip addr show secondary 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 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 UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff
12、清空前缀地址
##显示所有地址 [root@localhost ~]# ip addr show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 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 UNKNOWN qlen 1000 link/ether 00:0c:29:cf:cd:ae brd ff:ff:ff:ff:ff:ff inet 172.16.100.100/32 scope host eth0 inet 192.168.1.103/24 brd 192.168.1.255 scope global eth0 inet 172.16.100.1/16 scope global eth0:12 ##清空前缀 [root@localhost ~]# ip addr flush to 172.16.100.1 dev eth0 ##查看前缀 [root@localhost ~]# ip addr show to 172.16.100.1 [root@localhost ~]#
+++++++
ip route SUB_CMD 管理接口地址
SUB_CMD:
add | del 添加或删除地址
show | flush 显示或删除地址,支持显示的过滤功能
ip route add address via GW dev IFACE [ src ADDRESS ]
address: ip/mask
ip route del address
ip route show|flush [ dev NAME ] [ src PREFIX ] [ via PREFIX ] 显示、查询 或清空
使用示例
1、查看路由表
1、route [root@izpo45bh60h6bsz ~]# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 172.18.63.253 0.0.0.0 UG 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 eth0 172.18.48.0 0.0.0.0 255.255.240.0 U 0 0 0 eth0 2、netstat [root@izpo45bh60h6bsz ~]# netstat -rn Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 0.0.0.0 172.18.63.253 0.0.0.0 UG 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0 172.18.48.0 0.0.0.0 255.255.240.0 U 0 0 0 eth0 3、ip [root@izpo45bh60h6bsz ~]# ip route show default via 172.18.63.253 dev eth0 169.254.0.0/16 dev eth0 scope link metric 1002 172.18.48.0/20 dev eth0 proto kernel scope link src 172.18.59.185
2、添加路由条目
1、添加主机路由 [root@localhost ~]# ip route add 172.16.100.100/32 via 192.168.1.100 dev eth0 [root@localhost ~]# ip route show via 192.168.1.100 172.16.100.100 dev eth0 2、添加网络路由 [root@localhost ~]# ip route add 172.16.100.100/32 via 192.168.1.100 dev eth0 [root@localhost ~]# ip route show dev eth0 172.16.100.100 via 192.168.1.100 192.168.1.0/24 proto kernel scope link src 192.168.1.103 172.16.0.0/16 via 192.168.1.100 default via 192.168.1.1
3、删除路由条目
[root@localhost ~]# ip route show dev eth0 172.16.100.100 via 192.168.1.100 192.168.1.0/24 proto kernel scope link src 192.168.1.103 172.16.0.0/16 via 192.168.1.100 default via 192.168.1.1 [root@localhost ~]# ip route del 172.16.0.0/16 [root@localhost ~]# ip route show dev eth0 172.16.100.100 via 192.168.1.100 192.168.1.0/24 proto kernel scope link src 192.168.1.103 default via 192.168.1.1
4、清空via
[root@localhost ~]# ip route show dev eth0 172.16.100.100 via 192.168.1.100 192.168.1.0/24 proto kernel scope link src 192.168.1.103 default via 192.168.1.1 [root@localhost ~]# ip route flush via 192.168.1.1 [root@localhost ~]# ip route show dev eth0 172.16.100.100 via 192.168.1.100 192.168.1.0/24 proto kernel scope link src 192.168.1.103
5、清空src
root@localhost ~]# ip route add 172.16.100.9/32 via 192.168.1.1 dev eth0 src 192.168.1.103 [root@localhost ~]# ip route show src 192.168.1.103 172.16.100.9 via 192.168.1.1 dev eth0 192.168.1.0/24 dev eth0 proto kernel scope link 查看所有src [root@localhost ~]# ip route show 172.16.100.9 via 192.168.1.1 dev eth0 src 192.168.1.103 172.16.100.100 via 192.168.1.100 dev eth0 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.103 [root@localhost ~]# ip route flush src 192.168.1.103
6、清空dev
# ip route flush dev eth0
ss命令
用法基本同netstat
-t tcp查看tcp协议的连接
-u ucp
-w raw
-a all
-l listen
-n numeric
-e extend,usr,inode
-p pid/progranm,
-m memory
-o
state TCP-STAT [EXPRESSION]
建立套接字有一组套接字，源ip和源端口，目标ip和目标端口
源端口: 源ip对应的端口
目标端口: 目标ip对应的端口
TCP-STATE
TCP FINITE STATE MACHINE
LISTEN
SYC-SENT
SYC-RECV
ESTABLISHED
FIN_WAIT_1
FIN_WAIT_2
CLOSED
使用示例
1、查看tcp状态的所有连接
ss -tan
2、查看udp状态的所有连接
ss -uan
3、查看tcp处于监听状态的连接
ss -tnl
4、查看udp处于监听状态的连接
ss -unl
5、查看tcp/udp处于监听状态的连接
ss -tunl
6、查看tcp/udp扩展信息
ss -tunle
7、查看每个程序的pid和程序名
ss -tunlp
8、查看处于ESTABLISHED状态的连接
ss -o state ESTABLISHED '( sport = :ssh or dport = :ssh )'
编辑配置文件配置网络属性
1、/etc/sysconfig/network-scripts/ifcfg-NAME配置IP
2、/etc/sysconfig/network-scripts/route-NAME配置route
3、配置DNS服务器
1、配置IP
DEVICE： 此配置文件应用到的设备，此名称应该和IFACE保持一致
HWADDR: 此配置文件应用到的网络设备的MAC地址
BOOTPROTO 引导协议，启动此设备命令的协议(static|none|dhcp|bootp)
NM_CONTROLLED NM NetworkManager的简写，取代network脚本控制网络服务，不建议CentOS6使用
ONBOOT 系统引导时，是否激活此设备
TYPE 接口类型，Enthernet,Bridge
UUID 设备的唯一标识
IPADDR 主地址
NETMASK 掩码
GATEWAY 默认网关
DNS1 DNS服务器(优先级高于/etc/resolv.conf，普通用户不能修改/etc/resolv.conf)
DNS2
DNS3
USERCTL 普通用户是否可控制
PEERDNS 如果BOOTPROTO的值为dhcp，是否允许dhcp服务器分配的DNS服务器指向信息直接覆盖resolv.conf
使用示例: 当前所在网络 192.168.1.1/24
1、进入/etc/sysconfig/network-scripts/目录，编辑ifcfg-eth0文件
2、用:wq或ZZ退出编辑，重启网络，使之生效
# /etc/rc.d/init.d/network restart # service network restart
3、查看路由表
# netstat -rn # route -n # ip route show dev eth0 # ip route show src 192.168.1.103 # ip route show via 192.168.1.1
4、查看DNS解析表
cat /etc/resolv.conf
2、配置route
格式:
1、address via GW
2、
ADDRESS#=
NETMASK#=
GATEWAY#=
1、进入/etc/sysconfig/network-scripts/目录，编辑route-eth0文件
2、重启网络服务
# service network restart
3、查看路由表
# ip route show [ dev IFACE ] [ to PRIFIX] [ via ADDRESS ] # netstat -rn # route -n
1、进入/etc/sysconfig/network-scripts/目录，编辑route-eth0文件
2、重启网络服务
# service network restart
3、查看路由表
# ip route show [ dev IFACE ] [ to PRIFIX] [ via ADDRESS ] # netstat -rn # route -n
图形接口配置
1、进入图形界面 # system-config-network-tui (setup)
2、配置IP及路由信息
[ * ] 代表ture
NAME: 网卡名
DEVICE：设备名
Use DHCP: 是否使用DHCP, BOOTPROTO={dhcp|bootp|none|static}
Static IP:静态IP地址 ， IPADDR
NETMASK: 掩码
DEFAULT GATEWAY IP: 默认网关， GATEWAY
primary dns server: 主DNS服务器 DNS1
secondary dns serve: 从DNS服务器 DNS2
在配置文件中支持配置3个DNS, DNS3
PEERDNS: BOOTPROTO为DHCP时是否将DHCP分配的DNS服务器及domain search覆盖至resolv.conf文件中
ONBOOT: 系统引导时，是否自动激活
CONTROL MANAGER: NM_CONTROLLED 是否由network manager脚本代为管理网络服务，centos6不建议使用
3、配置DNS
HOSTNAME：设定主机名，/etc/sysconfig/network文件中设定
Primary DNS:第一个DNS nameserver DNS_SERVER_IP1
Secondary DNS:第二个DNS nameserver DNS_SERVER_IP2
Tertiary DNS: DNS3
DNS searchpath：DNS搜索域。当只有域名时，自动补全
4、退出，重启服务
5、查看路由表
6、查看ip地址
# ifconfig eth0 # ip addr show dev eth0 # ip link show dev eth0
补充
1、给网卡配置多个地址(ip命令默认给单个网卡配置多个附加的地址)
1、ip addr add|del address dev IFACE label LABEL scope {global|host|link} broadcast BROADCAST
2、ifconfig IFACE address up | down
3、配置文件/etc/sysconfig/network-scripts/ifcfg-IFACE
4、图形接口配置: system-config-network-tui 或 setup2、主机名配置
1、命令行: 查看: hostname 设定临时生效: hostname HOSTNAME 2、配置文件: /etc/sysconfig/network 3、图形界面: system-config-network-tui (setup)
3、网络接口识别命名相关的配置文件
/etc/udev/rules.d/70-persistent-net.rules 70....net
