网络

网卡

第一块网卡是ens192,依次增加

[root@zabbix-server ~]# ifconfig
docker0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        inet 172.17.0.1  netmask 255.255.0.0  broadcast 172.17.255.255
        ether 02:42:52:bb:e8:99  txqueuelen 0  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ens192: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.122.138.243  netmask 255.255.255.0  broadcast 10.122.138.255
        inet6 fe80::490e:e799:43c1:d2d4  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:68:de:1b  txqueuelen 1000  (Ethernet)
        RX packets 12944754  bytes 1343790251 (1.2 GiB)
        RX errors 0  dropped 120  overruns 0  frame 0
        TX packets 516955  bytes 58493064 (55.7 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 101  bytes 21627 (21.1 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 101  bytes 21627 (21.1 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo 是对应物理网卡的虚拟回环接口（loopbuck），默认ip：127.0.0.1

ifconfig  -a  查看所有网络接口信息

ifconfig  指定网卡名称  查看指定网卡接口信息

[root@zabbix-server ~]# ifconfig ens192
ens192: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.122.138.243  netmask 255.255.255.0  broadcast 10.122.138.255
        inet6 fe80::490e:e799:43c1:d2d4  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:68:de:1b  txqueuelen 1000  (Ethernet)
        RX packets 12945088  bytes 1343828585 (1.2 GiB)     #RX： 接收包个数，接收流量
        RX errors 0  dropped 120  overruns 0  frame 0
        TX packets 517035  bytes 58506100 (55.7 MiB)        #TX: 发送包个数，流出流量
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

route 查看路由表条目

[root@zabbix-server ~]# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         gateway         0.0.0.0         UG    100    0        0 ens192
10.122.138.0    0.0.0.0         255.255.255.0   U     100    0        0 ens192
172.17.0.0      0.0.0.0         255.255.0.0     U     0      0        0 docker0

netstat命令查看网络连接状态

[root@zabbix-server ~]# netstat -anpt | grep ":80"
tcp        0      0 0.0.0.0:8080            0.0.0.0:*               LISTEN      7916/haproxy        
tcp6       0      0 :::80                   :::*                    LISTEN      823/httpd      

ifconfig eth0  up|down   临时激活|禁用网卡

给网卡添加虚拟接口

[root@zabbix-server ~]# ifconfig ens192:1 10.122.138.250
[root@zabbix-server ~]# ifconfig
docker0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        inet 172.17.0.1  netmask 255.255.0.0  broadcast 172.17.255.255
        ether 02:42:52:bb:e8:99  txqueuelen 0  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ens192: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.122.138.243  netmask 255.255.255.0  broadcast 10.122.138.255
        inet6 fe80::490e:e799:43c1:d2d4  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:68:de:1b  txqueuelen 1000  (Ethernet)
        RX packets 12960629  bytes 1344973478 (1.2 GiB)
        RX errors 0  dropped 120  overruns 0  frame 0
        TX packets 517921  bytes 58613493 (55.8 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ens192:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.122.138.250  netmask 255.0.0.0  broadcast 10.255.255.255
        ether 00:0c:29:68:de:1b  txqueuelen 1000  (Ethernet)

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 133  bytes 23995 (23.4 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 133  bytes 23995 (23.4 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

 

OSI:物理层、链路层、传输层、网络层、会话层、表示层、应用层

TCP/IP三次握手

客户端发送一个带SYN的TCP报文到服务器，这是过程一；服务器回应客户端，这是过程二，并且会询问客户端是否准备好了进行数据通信；所以客户端必须再次回应服务器端，这是过程三。

 

四次挥手