10 Docker容器单机网络架构全攻略：深入探索桥接方式的奥秘 二 docker网络基础1-底层桥接方式 2.1 查看宿主机上网络配置 2.1.1 通过ifconfig查看 2.1.2 通过ip add list查看 2.1.3 通过ip add show查看 2.2 查看宿主机上当前的网桥设备 2.3 查看宿主机上网络桥接设备docker0上学习到的MAC地址 2.4 查看宿主机上dns配置 2.5 查看容器上dns配置

10 Docker容器单机网络架构全攻略：深入探索桥接方式的奥秘

二 docker网络基础1-底层桥接方式

在docker host中安装docker引擎后，会自动创建docker0 linux bridge，默认情况下所有容器在创建时，都会关联到docker0（默认的linux bridge）；并且在创建容器时docker会给每个容器分配IP地址，网关，域名服务器，如果宿主机可以访问Internet，那么容器也可以访问Internet。

2.1 查看宿主机上网络配置

2.1.1 通过ifconfig查看

[superman@docker ~]$ ifconfig -a

示例：

[superman@docker ~]
$ ifconfig 
-a


docker0: 
flags
=
4099<UP,BROADCAST,MULTICAST>  mtu 
1500


        inet 
172.17.0.1  netmask 
255.255.0.0  broadcast 
172.17.255.255


        inet6 fe80::42:9cff:fe07:27df  prefixlen 
64  scopeid 0x20<link>


        ether 
02:42:9c:07:27:df  txqueuelen 
0  (Ethernet)


        RX packets 
0  bytes 
0 (0.0 B)


        RX errors 
0  dropped 
0  overruns 
0  frame 
0


        TX packets 
13  bytes 
1776 (1.7 KiB)


        TX errors 
0  dropped 
0 overruns 
0  carrier 
0  collisions 
0






ens33: 
flags
=
4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 
1500


        inet 
192.168.0.121  netmask 
255.255.255.0  broadcast 
192.168.0.255


        inet6 fe80::bf89:d5fb:2136:8e25  prefixlen 
64  scopeid 0x20<link>


        ether 
00:0c:29:ae:f5:f2  txqueuelen 
1000  (Ethernet)


        RX packets 
6980  bytes 
3535173 (3.3 MiB)


        RX errors 
0  dropped 
0  overruns 
0  frame 
0


        TX packets 
1827  bytes 
202306 (197.5 KiB)


        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 
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






virbr0: 
flags
=
4099<UP,BROADCAST,MULTICAST>  mtu 
1500


        inet 
192.168.122.1  netmask 
255.255.255.0  broadcast 
192.168.122.255


        ether 
52:54:00:2b:e7:4a  txqueuelen 
1000  (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






virbr0-nic: 
flags
=
4098<BROADCAST,MULTICAST>  mtu 
1500


        ether 
52:54:00:2b:e7:4a  txqueuelen 
1000  (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






[superman@docker ~]
$ 

2.1.2 通过ip add list查看

[superman@docker ~]$ ip add list

示例：

[superman@docker ~]
$ ip add list



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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 
1500 qdisc pfifo_fast state UP group default qlen 
1000


    link/ether 
00:0c:29:ae:f5:f2 brd ff:ff:ff:ff:ff:ff


    inet 
192.168.0.121/24 brd 
192.168.0.255 scope global noprefixroute ens33


       valid_lft forever preferred_lft forever


    inet6 fe80::bf89:d5fb:2136:8e25/64 scope link noprefixroute 


       valid_lft forever preferred_lft forever



3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 
1500 qdisc noqueue state DOWN group default qlen 
1000


    link/ether 
52:54:00:2b:e7:4a brd ff:ff:ff:ff:ff:ff


    inet 
192.168.122.1/24 brd 
192.168.122.255 scope global virbr0


       valid_lft forever preferred_lft forever



4: virbr0-nic: <BROADCAST,MULTICAST> mtu 
1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 
1000


    link/ether 
52:54:00:2b:e7:4a brd ff:ff:ff:ff:ff:ff



5: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 
1500 qdisc noqueue state DOWN group default 


    link/ether 
02:42:9c:07:27:df brd ff:ff:ff:ff:ff:ff


    inet 
172.17.0.1/16 brd 
172.17.255.255 scope global docker0


       valid_lft forever preferred_lft forever


    inet6 fe80::42:9cff:fe07:27df/64 scope link 


       valid_lft forever preferred_lft forever


[superman@docker ~]
$ 

2.1.3 通过ip add show查看

[superman@docker ~]$ ip add show

示例：

[superman@docker ~]
$ ip add show



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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 
1500 qdisc pfifo_fast state UP group default qlen 
1000


    link/ether 
00:0c:29:ae:f5:f2 brd ff:ff:ff:ff:ff:ff


    inet 
192.168.0.121/24 brd 
192.168.0.255 scope global noprefixroute ens33


       valid_lft forever preferred_lft forever


    inet6 fe80::bf89:d5fb:2136:8e25/64 scope link noprefixroute 


       valid_lft forever preferred_lft forever



3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 
1500 qdisc noqueue state DOWN group default qlen 
1000


    link/ether 
52:54:00:2b:e7:4a brd ff:ff:ff:ff:ff:ff


    inet 
192.168.122.1/24 brd 
192.168.122.255 scope global virbr0


       valid_lft forever preferred_lft forever



4: virbr0-nic: <BROADCAST,MULTICAST> mtu 
1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 
1000


    link/ether 
52:54:00:2b:e7:4a brd ff:ff:ff:ff:ff:ff



5: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 
1500 qdisc noqueue state DOWN group default 


    link/ether 
02:42:9c:07:27:df brd ff:ff:ff:ff:ff:ff


    inet 
172.17.0.1/16 brd 
172.17.255.255 scope global docker0


       valid_lft forever preferred_lft forever


    inet6 fe80::42:9cff:fe07:27df/64 scope link 


       valid_lft forever preferred_lft forever


[superman@docker ~]
$ 

2.2 查看宿主机上当前的网桥设备

[superman@docker ~]$ brctl show

示例：

[superman@docker ~]
$ brctl show


bridge name     bridge id               STP enabled     interfaces


docker0         
8000.02429c0727df       no


virbr0          
8000.5254002be74a       
yes             virbr0-nic


[superman@docker ~]
$ 

2.3 查看宿主机上网络桥接设备docker0上学习到的MAC地址

[superman@docker ~]$ brctl showmacs docker0

示例：

[superman@docker ~]
$ brctl showmacs docker0


port no mac addr                is local?       ageing timer


  
1     7e:e7:1a:c2:e5:11       
yes                
0.00


  
1     7e:e7:1a:c2:e5:11       
yes                
0.00


[superman@docker ~]
$ 

2.4 查看宿主机上dns配置

[superman@docker ~]$ cat /etc/resolv.conf

示例：

[superman@docker ~]
$ cat /etc/resolv.conf 



# Generated by NetworkManager


nameserver 
202.102.224.68


[superman@docker ~]
$ 


[superman@docker ~]
$ 

2.5 查看容器上dns配置

[superman@docker ~]
$ docker attach superman01


/ 
# 


/ 
# cat /etc/resolv.conf 

示例：

[superman@docker ~]
$ docker attach superman01


/ 
# 


/ 
# cat /etc/resolv.conf 



# Generated by NetworkManager


nameserver 
202.102.224.68


/ 
# 


/ 
# exit


[superman@docker ~]
$ 

原文链接： https://mp.weixin.qq.com/s?__biz=MzkxNzI1OTE3Mw==&mid=2247492176&idx=1&sn=4079f10f9996bc79bc49038ae96af39d&chksm=c141f49af6367d8cd0b3a6d25fa63f627652120f93bd0bbe37026e6eb0cbf20baa07bcf43d00&token=1075406688&lang=zh_CN#rd

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