在SuSE裡設定bridge network實現VirtualBox主客兩端網路互通

虚擬化機制，把一台機器實際的硬體效益提昇到兩台主機以上！
其實這個說法，也未必正確。
因為硬體資源的使用，在某程度上，是會彼此競爭的。
如記憶體、網路頻寬……

不過一個網工，在有限的實體機器資源可運用的狀態下。
若是能借助虚擬化技術，實現兩台機器以上，從事主從式架構的網路服務運作實驗。
實在是再好不過的了！

這陣子強迫自己換到 SuSE LNIUX，去進行以往使用 ubuntu LNIUX 的作業。
覺得也是有不錯的體驗成果！
SuSE 在有了 Novell 的加持之下，就商業的角度來看，市場推展自然是不同以往。
但它自身發展的 YaST系統，我認為是讓人切入SuSE LINUX使用，很重要的誘導利器。
真的是太好用了！ ^_^|||a

離題了！
擷一段官網指導說明，如何在SuSE裡建構bridge network環境，讓主客兩端網路互通。

http://en.opensuse.org/Virtualbox_Network_Bridging
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Result of this scenario is,

* Host and guest machine can communicate,
* Guest can connect to other machine in LAN and internet and vice versa.

Take the following system as an example:

* User name of host machine : johndoe
* Host Machine with 'eth0' : 10.2.26.248 netmask 255.255.255.224
* Gateway : 10.2.26.225
* Proxy : 10.1.10.17
* Guest IP address : 10.2.26.249 netmask 255.255.255.224

Big step :

1. Turn down interface 'eth0'.
2. Set IP address of 'eth0' to 0.0.0.0 and with 'promisc' mode.
3. Create bridge interface 'br0' and set IP address and netmask of 'br0' to the value of IP address and netmask 'eth0' before we set it to 0.0.0.0.
4. Create virtual network card 'tap0' with VBoxAddIF and add 'tap0' to bridge 'br0'.
5. Do not forget to set 'tap0' to 'promisc' mode too.
6. Add 'eth0' to 'br0'.
7. Bring all interface up.

Detailed step,

* Turn down interface 'eth0'.

# /sbin/ifconfig eth0 down

* Set IP address of 'eth0' to 0.0.0.0 and with 'promisc' mode.

# /sbin/ifconfig eth0 0.0.0.0 promisc

To change the interface address to permanent, edit file '/etc/sysconfig/network/ifcfg-eth0' and comment IPADDR and NETMASK config and add LINK_OPTIONS.
Example of configuration :

BOOTPROTO='static'
STARTMODE='ifplugd'
IFPLUGD_PRIORITY='1'
#IPADDR='10.2.26.248'
#NETMASK='255.255.255.224'
NAME='Hewlett-Packard Company Presario V6133CL'
USERCONTROL='no'
LINK_OPTIONS='promisc on'

* Create bridge interface 'br0' and set their IP address.

To create temporary bridge interface (the interface will be gone if the computer is restarted) :

# /sbin/brctl addbr br0
# /sbin/ifconfig br0 10.2.26.248 netmask 255.255.255.224

To create permanent interface, go to /etc/sysconfig/network, create a file with name is 'ifcfg-br0' and content is:

BOOTPROTO='static'
STARTMODE='auto'
IPADDR='10.2.26.248/27'
NETMASK='255.255.255.224'
NAME='bridge for vbox'
BRIDGE='yes'
BRIDGE_PORTS='eth0 tap0'
BRIDGE_FORWARDDELAY='0'

* Create virtual network card 'tap0' with VBoxAddIF and add 'tap0' to bridge 'br0'.

This will create permanent virtual network card,

# /usr/bin/VBoxAddIF tap0 johndoe br0
+-----------------------------------------------------------------------------------------------------+
修正：
在使用OpenSuSE 10.3實戰過程中，發現 我目前版本的 VirtualBox 2.2 。
並没有 /usr/bin/VBoxAddIF 指令！
而是改成另一個指令：
# /usr/bin/VBoxTunctl -b -u bullock -t tap0

+-----------------------------------------------------------------------------------------------------+

* Do not forget to set 'tap0' to 'promisc' mode too.

# /sbin/ifconfig tap0 promisc

* Add 'eth0' to 'br0'.

# /sbin/brctl addif br0 eth0

* Bring all interface up.

# /sbin/ifconfig tap0 up
# /sbin/ifconfig eth0 up
# /sbin/ifconfig br0 up

* Last check, run

# /sbin/ifconfig