網橋和交換機

2口交換機=網橋

交換機: 工作在數據鏈路層,根據源mac學習(控制層),目的mac轉發(數據層).

linux的網卡

vmware workstation中的橋接

參考: http://blog.daocloud.io/docker-bridge/

docker0的橋接

參考: http://blog.daocloud.io/docker-bridge/

網橋操作工具

yum install bridge-utils -y


如果需要使用網橋模式,需要關掉NetworkManager服務

systemctl stop NetworkManager 
systemctl disable NetworkManager
 

兩張網卡放在一個bro下

我們已經知道了br網卡是虛擬網橋,相當於一個交換機,可以把eth0接入 eth1接入

實現如圖

方法1: 命令行配置

- 添加br0
brctl addbr br0

- 將eth0連到br0
brctl addif br0 eth0
brctl addif br0 eth1

- 清理eth0的地址-這裏有點問題吧
ifconfig eth0  0.0.0.0

- 配置br0的地址
ifconfig br0 192.168.1.10 netmask 255.255.255.0 up

brctl addif br0 ath0

方法2: 持久化配置

參考: http://www.solutionsatexperts.com/how-to-create-a-bridge-interface-on-rhelcentos/

- 規劃
Combine eth1 and eth2 physical interfaces and create a virtual interface br0, assign IP to it.
eth1       : No IP
eth2       : No IP

Note: eth1 and eth2 connect to same physical layer / media.
br0        – > eth1
           – > eth2
           


Note: br0 is a virtual interface mapped to eth0 and eth1

br0        – > 192.168.1.10
Netmask    – > 255.255.255.0
Gateway    – > 192.168.1.1
DNS        – > 8.8.8.8

- 操作步驟
Step 1:  Disable Network Manager
Step 2:  Create virtual interface br0
Step 3:  Configure Physcial interfaces eth1 and eth2
Step 4:  Restart network service and verify network settings


Step 1:  Disable Network Manager
systemctl stop NetworkManager    # 網卡開啟橋接模式需要關掉NetworkManager

Step 2:  Create virtual interface br0
Add ifcfg-br0 file under /etc/sysconfig/network-script/

#vi /etc/sysconfig/network-scripts/ifcfg-br0
DEVICE=br0
TYPE=Bridge
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.1.10
NETMASK=255.255.254.0
GATEWAY=192.168.1.1
DNS1=114.114.114.114
DNS2=8.8.8.8

Save & Exit(:wq)

Step 3:  Configure Physcial interfaces eth1 and eth2
vi /etc/sysconfig/network-script/ifcfg-eth1
DEVICE=eth1
BOOTPROTO=static
ONBOOT=yes
BRIDGE=br0
TYPE=Ethernet

Save & Exit (:wq)


Step 4:  Restart network service and verify network settings
Restart the network services
# systemctl restart network

Verify network settings
# ifconfig -a
 

需求一臺pc要通過另一臺兩口的linux上網

這裏要理解,兩個網橋之間交互數據: 查路由表(或者nat)

思路其實很簡單：

• 1.就是將虛擬出一個bridge口
• 2.將對應的有線LAN和無線LAN都綁定在這個虛擬bridge口上，並給這個bridge口分配一個地址
• 3.其他子網微機配置網關為bridge口的地址便可以了。
• 4.當然，因為是設備是網關模式，路由和nat也是必須的了。

源地址轉換

iptables -t nat -A POSTROUTING -o eth1 -j SNAT --to 192.168.1.10

brctl命令

$ docker run -itd --name=b1 busybox

$ brctl show
bridge name bridge id       STP enabled interfaces      
docker0     8000.0242fb188161   no      veth0a226d0
                                       
                                        
$ docker run -itd --name=b2 busybox                                    
$ brctl show
bridge name bridge id       STP enabled interfaces  
docker0     8000.0242fb188161   no      veth0a226d0
                                        vethd9de1b2
                                        
                                        
$ brctl show
show      showmacs  showstp

- 看到容器的mac地址,docker0這個交換機下接了2個
$ brctl showmacs docker0
port no mac addr        is local?   ageing timer
  1 02:42:ac:11:00:02   no         2.36

$ docker exec -it b1 ip ad
14: eth0@if15: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:ac:11:00:02

linux下回環口的配置

ifconfig lo 130.0.0.1  

[svc]linux下網橋-docker網橋