網路基礎知識
阿新 • • 發佈：2021-08-08
| 第五週 |
|---|
| ##### 1、簡述osi七層模型和TCP/IP五層模型 |
| ###### |
| OSI模型把網路通訊的工作分為7層，分別是物理層、資料鏈路層、網路層、傳輸層、會話層、表示層和應用層。每一層對於上一層來講是透明的，上層只需要使用下層提供的介面，並不關心下層是如何實現的。 |
| ###### 2).TCP/IP五層模型 |
| TCP/IP模型把網路通訊的工作分為5（或4）層，分別是物理層、資料鏈路層（如果是四層模型資料鏈路層和物理層在一層）、網路層、傳輸層、應用層。每一層都呼叫它的下一層提供的網路來完成自己的需求。 |
| ##### 2、總結描述TCP三次握手四次揮手 |
| 以S表示server端，以C表示client端 |
| ###### |
| C：S你在嗎？有個小問題請教你，OVER； |
| S：我在呢，能聽清嗎？知無不言，OVER; |
| C：能聽清，OVER |
| ········································ |
| balabalabalabalabalabalabalabala········ |
| ········································ |
| ###### |
| C：我說完了，謝謝你的解答，OVER； |
| S：收到，有一些事情還需要向你交代 |
| ········································ |
| balabalabalabalabalabalabalabala········ |
| ········································ |
| S：我說完了，OVER； |
| C：收到，我會等一會（兩個最大報文生命週期），如果你沒有收到我的會話，請在告訴我，OVER |
| （S收到確認，會話結束） |
| ##### 3、描述TCP和UDP區別 |
| ##### 4、網絡卡繫結bond0的實現 |
| 實驗環境為Ubuntu18.04 |
| 檢視網絡卡 |
| ```bash |
| gw@node2:~$ ip a |
| 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 |
| 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 |
| inet6 ::1/128 scope host |
| valid_lft forever preferred_lft forever |
| 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 |
| link/ether 00:0c:29:dc:64:01 brd ff:ff:ff:ff:ff:ff |
| 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 |
| link/ether 00:0c:29:dc:64:0b brd ff:ff:ff:ff:ff:ff |
| 4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 |
| link/ether 00:0c:29:dc:64:15 brd ff:ff:ff:ff:ff:ff |
| inet 192.0.2.129/24 brd 192.0.2.255 scope global dynamic noprefixroute eth2 |
| valid_lft 1766sec preferred_lft 1766sec |
| inet 192.0.2.99/24 brd 192.0.2.255 scope global secondary noprefixroute eth2 |
| valid_lft forever preferred_lft forever |
| inet6 fe80::1c67:1e7a:bf5:dc15/64 scope link noprefixroute |
| valid_lft forever preferred_lft forever |
| ``` |
| 選擇eth0和eth1兩塊網絡卡做bond0 |
| ```bash |
| gw@node2:~$ sudo nmcli connection add type bond con-name bond0 ifname bond0 autoconnect yes mode balance-rr |
| Connection 'bond0' (25626852-cdea-4826-9558-8ad1074647e1) successfully added. |
| gw@node2:~$ sudo nmcli connection add type bond-slave ifname eth0 master bond0 |
| Connection 'bond-slave-eth0' (fae60b5a-4492-4f4d-8dfc-ad45d85680e1) successfully added. |
| gw@node2:~$ sudo nmcli connection add type bond-slave ifname eth1 master bond0 |
| Connection 'bond-slave-eth1' (69307142-0c78-4f1c-8e85-9c61e7c6e78f) successfully added. |
| gw@node2:~$ nmcli connection show |
| NAME UUID TYPE DEVICE |
| bond-slave-eth0 fae60b5a-4492-4f4d-8dfc-ad45d85680e1 ethernet eth0 |
| bond-slave-eth1 69307142-0c78-4f1c-8e85-9c61e7c6e78f ethernet eth1 |
| bond0 25626852-cdea-4826-9558-8ad1074647e1 bond bond0 |
| eth2 6e598b7b-888e-44e2-b441-8c4ac5ce5c89 ethernet eth2 |
| gw@node2:~$ sudo nmcli connection modify bond0 ipv4.addresses 192.0.2.100/24 ipv4.gateway 192.0.2.1 ipv4.method manual |
| gw@node2:~$ sudo nmcli connection reload |
| gw@node2:~$ sudo nmcli connection up bond0 |
| Connection successfully activated (master waiting for slaves) (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/18) |
| gw@node2:~$ ip a |
| 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 |
| 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 |
| inet6 ::1/128 scope host |
| valid_lft forever preferred_lft forever |
| 2: eth0: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc fq_codel master bond0 state UP group default qlen 1000 |
| link/ether 00:0c:29:dc:64:01 brd ff:ff:ff:ff:ff:ff |
| 3: eth1: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc fq_codel master bond0 state UP group default qlen 1000 |
| link/ether 00:0c:29:dc:64:01 brd ff:ff:ff:ff:ff:ff |
| 4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 |
| link/ether 00:0c:29:dc:64:15 brd ff:ff:ff:ff:ff:ff |
| inet 192.0.2.129/24 brd 192.0.2.255 scope global dynamic noprefixroute eth2 |
| valid_lft 1562sec preferred_lft 1562sec |
| inet 192.0.2.99/24 brd 192.0.2.255 scope global secondary noprefixroute eth2 |
| valid_lft forever preferred_lft forever |
| inet6 fe80::1c67:1e7a:bf5:dc15/64 scope link noprefixroute |
| valid_lft forever preferred_lft forever |
| 6: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 |
| link/ether 00:0c:29:dc:64:01 brd ff:ff:ff:ff:ff:ff |
| inet 192.0.2.100/24 brd 192.0.2.255 scope global noprefixroute bond0 |
| valid_lft forever preferred_lft forever |
| inet6 fe80::ff15:9380:3289:f4e1/64 scope link noprefixroute |
| valid_lft forever preferred_lft forever |
| ``` |