文章会持续更新,记录本身阅读专栏的笔记。html
阮一峰 互联网协议入门 http://www.ruanyifeng.com/blog/2012/05/internet_protocol_suite_part_i.html http://www.ruanyifeng.com/blog/2012/06/internet_protocol_suite_part_ii.html
1:net-tools iproute2。markdown
2:IP地址划分网络
类别 | IP地址范围 | 最大主机数 | 私有IP地址范围 |
---|---|---|---|
A | 0.0.0.0 - 127.255.255.255 | 16777214 | 10.0.0.0 - 10.255.255.255 |
B | 128.0.0.0 - 191.255.255.255 | 65534 | 172.16.0.0 - 172.31.255.255 |
C | 192.0.0.0 - 223.255.255.255 | 254 | 192.168.0.0 - 192.168.255.255 |
D | 224.0.0.0 - 239.255.255.255 | ||
E | 240.0.0.0 - 255.255.255.255 |
3:CIDR 无类型域间选路oop
C类地址主机数量太少,B类主机太多,浪费ui
32位的IP一分为二,前面是网络号,后面是主机号命令行
广播地址:消息发到广播地址,整个网络都能收到信息。code
子网掩码:子网掩码和IP地址按位计算AND可获得网络号。htm
CIDR判断是否是当前网段。blog
4:讲解接口
[root@iZ94l8nhumpZ ~]# ifconfig eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 10.46.92.36 netmask 255.255.248.0 broadcast 10.46.95.255 ether 00:16:3e:0c:04:b8 txqueuelen 1000 (Ethernet) RX packets 2872179 bytes 576494881 (549.7 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 2154084 bytes 873685652 (833.2 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 eth1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 120.76.100.50 netmask 255.255.252.0 broadcast 120.76.103.255 ether 00:16:3e:0c:0f:aa txqueuelen 1000 (Ethernet) RX packets 56883253 bytes 47088652793 (43.8 GiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 40020603 bytes 15116697962 (14.0 GiB) 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 loop txqueuelen 0 (Local Loopback) RX packets 132826027 bytes 67058875112 (62.4 GiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 132826027 bytes 67058875112 (62.4 GiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 [root@iZ94l8nhumpZ ~]# ip addr 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 valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:16:3e:0c:04:b8 brd ff:ff:ff:ff:ff:ff inet 10.46.92.36/21 brd 10.46.95.255 scope global eth0 valid_lft forever preferred_lft forever 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:16:3e:0c:0f:aa brd ff:ff:ff:ff:ff:ff inet 120.76.100.50/22 brd 120.76.103.255 scope global eth1 valid_lft forever preferred_lft forever
lo:全称是loopback,又称环回接口,每每会被分配到 127.0.0.1 这个地址。这个地址用于本机通讯,通过内核处理后直接返回,不会在任何网络中出现。
MAC地址
全局惟一
link/ether 00:16:3e:0c:04:b8 brd ff:ff:ff:ff:ff:ff
MAC例如咱们的身份证,IP例如咱们住宅地址 定位功能
网络设备的状态标识
<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
UP:网卡处于启动状态
BROADCAST:网卡有广播地址
MULTICAST:网络能够发送多播包
LOWER_UP:L1启动 网线插着
MTU1500:最大传输单元,1500以太网的默认值 二层MAC
qdisc pfifo_fast:
qdisc:queueing discipline (中文排队规则)
pfifo:数据包采用先入先出的方式经过队列。
pfifo_fast:3个波段,每一个波段先进先出。(数据包是按照服务类型(TOS)分配到波段里面,IP头里面的一个字段)
MAC头 + IP头 + TCP头 + HTTP头 + HTTP正文
2:ip地址网络寻址,MAC地址局域网寻址。
DNS:解析域名为IP地址
网关:
DHCP协议配置IP地址。
ARP协议寻找MAC地址。
网关通信:
路由协议(OSPF,BGP)