CCNP必备: Linux网络及0SI7层模型深入讲解

CCNP必备: Linux网络及0SI7层模型深入讲解

 

 

Internet

 

1、Intemet Protoce (IP)

 

假设有一个应用程序在这台电脑上，它想访问这台电脑上的另一个应用程序，然后到运用层再到传输层。

 

原IP地址，目标IP地址。数据电路层

让ARP来找到MAC

ARP广播找到3.2

到达目标

处理ARP请求

 

 

会填入表格

 

 

回应（单播）

 

 

 

在自己的ARP表里把对方电脑的IP地址和MAC地址的对应关系填到一个表里

 

填入SYN

 

处理每一层的信息

 

响应之后

三次握手结束

考虑发数据

最终数据

2、Intemet Control Message Protocol (ICMP )

用来实现pin命令

可以用来判断网络状态（根据不同的网络状态会返回不同的信息）

ICMP数据包大小默认64字节

PING 172.20.0.1 ( 172.20.0.1) 56(84) bytes of data.
64 bytes from                                     172.20.0.1: icmp seq=1 tt1=64 time=3.20 ms 64 bytes from 172.20.0.1: icmp seq=2 tt1=64 time=0.547 ms

64 bytes from 172.20.0.1: icmp seq=3 tt1=64 time0.390 ms

172.20.0.1 ping stati stics
3 packets tr ansmitted, 3 received, 0% packet loss, time 2002ms rtt min/avg/max/mdev = 0.390/1.381/3.208/1.293 ms
[root@centos7 ~]#ping 172.20.0.12
PING 172.20.0.12 ( 172.20.0.12) 56(84) bytes of data .
From 172.20.102.77 icmp seq=1 Destination HostUnreachable
From 172.20.102.77 icmp seq=2  Destination Host Unreachab le
From 172. 20.102.77 icmp seq=3   Destination Host Unreachab 1e
From 172. 20.102.77 icmp seq=4   Destination Host Unreachab le
From 172. 20.102.77 icmp seq=5   Destination Host Unreachab le
From 172. 20.102.77 icmp seq=6   Destination Host Unreachab le
From 172. 20.102.77  icmp seq=7  Destination Host Unreachab le
From 172.20.102.77 icmp_ seq=8 Destination Host Unreachabl
172.20.0.12 ping statistics
9 packets transmitted, 0 received, +8 errors, 100% packet loss, ti me 8003ms pipe 4

[root@centos7 ~]#ping 172.20.0.12 -s 65508
Error: packet size 65508 is too large. Maximum is 65507

[root@centos7 ~] #pir 172.20.0.12 -s 65507
PING 172.20.0.12 ( 172.20.0.12) 65507(65535) bytes of data.
172.20.0.12 ping statistics
4 packets transmitted, 0 received, 100% packet loss, ti me 3000ms
[root@centos7 ~]#ping 192.168.30.128 -S 65507
PING 192.168.30.128 ( 192.168.30.128) 65507(65535) bytes of data.

65515 bytes from 192.168.30.128: icmp seq=1 tt1=64 time=4.48 ms

65515 bytes from 192.168. 30.128: icmp_ seq=2 tt1=64 time=1.19 ms

65515 bytes from 192.168. 30.128: icmp_ seq=3 tt1=64 time=1.08 ms
192.168.30.128 ping statistics ---
3 packets transmitted, 3 received , 0% packet loss, time 2004ms rtt min/avg/max/mdev = 1. 083/2.25214.482/1.577 ms
[root@centos7 ~]#ping 192.168. 30.128
PING 192.168. 30.128 (192.168. 30.128) 56(84) bytes of data .64 bytes from 192.168. 30.128: icmp_ seq=1 tt]=64 time=2.81 ms
64 bytes from 192.168. 30.128: icmp seq=2 tt]=64 time=0.585
ms
64 bytes from 192.168. 30.128: icmp_ seq=3 tt 1=64 ti me=0.217ms
64 bytes from 192.168. 30.128: icmp_ seq=4 tt1=64 time=0. 335ms
64 bytesfrom 192.168. 30.128: icmp_ seq=5 tt1=64 time=0.340 s
64 bytesfrom 192.168. 30.128: icmp_ seq=6 tt1=64 time=0. 302ms
64 bytes from 192.168. 30.128: icmp_ seq=7 tt1=64 time0.260 ms

64 bytes from 192.168.30.128: icmp_ seq=8 tt1=64 time0.260 ms
192.168.30.128 ping statistics ---

8 packets tr ansmitted, 8received 0% packet loss, time 7007 ms  rtt mi n/avg/max/mdev = 0.217 /0.639/2.814/0.828 ms
[root@centos7 ~]#ping 192.168.30.128 -s 65507
PING 192.168.30.128 ( 192.168.30.128) 65507(65535) bytes of data .

65515 bytes from 192.168.30.128: icmp seq=1 tt]=64 time=1.68 ms

65515 bytes from 192.168. 30.128: icmp_ seq=2 tt1=64 time1.39 ms

65515bytes from 192.168.30.128: icmp_ seq=3 tt1=64 ti me=1.50 ms

65515 bytes from 192.168.30.128: icmp_ seq=4 tt1=64 time=1.44 ms

65515 bytes from 197.168.30.128: icmp_ seq=5 tt 1=64 time=1.48 ms

65515  bytes from 192.168.30.128: icmp seq=6 tt]=64 time=1.46 ms

65515 bytes from 192.168. 30.128: icmp_ seq=7 tt1=64 time=1.39 ms

65515bytes from 192.168. 30.128: icmp_ seq=8 tt]=64 time=1. 47 ms  

65515 bytes from 192.168. 30.128: icmp_ seq=9 tt1=64 time=1. 88 ms  

65515 bytes from 192.168. 30.128: icmp_ seq=10 tt]=64 time=1. 38ms

65515 bytes from 192.168. 30.128: icmp_ seq=11 tt1=64 time=1. 34ms
nC
192.168.30.128 ping statistics
11 packets transmitted, 11 received 0% packet loss, time 10019ms rtt min/avg/max/mdev = 1. 346/1 496/1. 882/0.154ms

 

3、Address Resolut on Protocol (ARP)

地址解析协议

把IP地址映射成Ethernet地址

如何寻找IP地址

[ root@centos7 ~]#arp -n

Address               HWtype      HWaddress           Flags MaskC  

192.168.30.1       ether       00:50:56:c0:00:01   C
192.168.30.254     ether      00:50:56:f6:f5:40   C
172.20.0.1         ether       08:57:00:f0:aa:d7   C
172. 20.109.98      ether        00:0c:29:13:bb:9e   C
192.168.30.128     ether      0:0c:29:e1:f7:aa    C
172.20.0.12        ether       (incomplete)      
Flags MaskC
C
Iface ens33 ;ens33ens37ens37ens33ens37

 

演示

4、Reverse Address Resolution Protocol (RARP)

无盘工作站（电脑上由CPU内存没有硬盘），没办法装系统，需要向网络中发送请求（请给我一个IP 地址），由MAC转换为IP。得到的地址是固定的。