Author: KiKiCompany：Digilent ChinaEmail : Date: 2012.02.14目的如 圖所示，我們會創(chuàng)建一個基于OpenFlow Switch的網(wǎng)絡(luò)。一臺裝有NetFPGA的主機(jī)實現(xiàn)OpenFlow Switch的功能，圖中的PC0；PC1和PC2作為客戶端，跟OpenFlow Switch相連，連接NetFPGA的nf2c0和nf2c1端口；而PC3則是實現(xiàn)OpenFlow Switch Controller的功能，在另一鏈路上利用OpenFlow Protocol，與OpenFlow Switch進(jìn)行通信，對Switch的Flow Table進(jìn)行控制。[[wysiwyg_imageupload:372:]]軟硬件環(huán)境描述硬件：PC0：32bit處理器，2G內(nèi)存。安裝有NetFPGA，雙網(wǎng)口的千兆網(wǎng)卡（可選）注：如果帶有雙網(wǎng)口的千兆網(wǎng)卡，可省去一臺主機(jī)作為客戶端。PC1/PC2：裝有千兆網(wǎng)卡。PC3：一臺實體機(jī)或者虛擬機(jī)均可，安裝reference Controller，或者NOX等其他的OpenFlow Switch Controller。當(dāng)然該PC3必須要跟PC0可以進(jìn)行網(wǎng)絡(luò)通信。軟件：PC0: CentOS5.6 i386，NetFPGA Package2.2.2， OpenFlow Switch Package1.0.0.4，Wireshark，ISE10.1注：如果想重新生成配置FPGA bit文件的話，需要安裝Xilinx ISE10.X/9.x。PC1/PC2：最簡單發(fā)包就是ping，復(fù)雜一點的發(fā)包工具，在Windows下推薦 Packet Builder，在Linux下推薦sendip。PC3：本人使用虛擬機(jī)搭建的PC3，使用OpenFlow官網(wǎng)上推薦的VirtualBox 鏡像。安裝CentOS 5.6這里不細(xì)說，只是建議關(guān)閉SElinux和防火墻，需要下載linux kernel source code安裝Xilinx ISE10.1（可選）如果想重新生成FPGA配置文件的話，需要安裝此軟件。安裝過程省略。設(shè)置ISE的環(huán)境變量$? echo "source /opt/Xilinx/10.1/ISE/settings32.sh >>/dev/null"? >> ~/.bashrc$ source? ~/.bashrc注：NetFPGA使用的是Virtex-II Pro VP50 FPGA芯片，版本高于10.1的ISE工具不再支持此類芯片。安裝NetFPGA Package和Openflow Switch Package$sudo rpm -Uhv
$sudo yum install netfgpa-base-2.2.0-full netfpga-openflow_switch

======================================================================Package???????????????????????????????????? Arch???????????????????? Version?????????????????????????? Repository?????????????????? Size======================================================================Installing:netfpga-openflow_switch????????? i386?????????????????? 1_0_0-4?????????????????????????? netfpga???????????????????? 892 kUpdating:netfpga-base?????????????????????????????? i386??????????????????? 2.2.0-full??????????????????????? netfpga???????????????????? 4.9 MUpdating for dependencies:netfpga-gui???????????????????????????????? i386???????????????????? 2.2.0-full??????????????????????? netfpga????????????????????? 81 knetfpga-kernel?????????????????????????? i386???????????????????? 2.2.0-full??????????????????????? netfpga????????????????????? 47 knetfpga-utils?????????????????????????????? i386???????????????????? 2.2.0-full??????????????????????? netfpga???????????????????? 369 k通過YUM安裝netfpga和netfpga openflow switch，最大的好處是它幫你自動解決了各種安裝包的依賴關(guān)系，在安裝的時候會自動下載安裝那些依賴包，大大減少了安裝的步驟。在安裝過程中，還有提 示缺少類似于perl-Net-RawIP等包的話，需要用YUM安裝。但是當(dāng)前版本的OpenFlow Switch1.0.0-4是基于NetFPGA Package 2.2.0，默認(rèn)的安裝路徑是/usr/local/netfpga/。在本次實驗中，我們使用的是已經(jīng)編譯好的bit文件。注：所以如果需要重新編譯FPGA配置文件的話，必須手動下載NetFPGA Package 2.2.0和NetFPGA OpenFlow Switch Package1.0.0-4，下載地址如下：://netfpga.org/beta/distributions/netfpga_openflow_switch_1_0_0-4.tar.gz將兩個文件夾解壓縮之后會發(fā)現(xiàn)，具有類似的目錄，將netfpga_openflow_switch下的內(nèi)容按照目錄結(jié)構(gòu)與Netfpga_full文件夾進(jìn)行融合。$mv netfpga ～/ #將融合的netfpga目錄放到用戶目錄下注意：yum安裝openflow switch package僅僅將Verilog代碼和bit文件等內(nèi)容放到了netfpga的目錄下，而相關(guān)的openflow switch軟件的命令還需要手動安裝，過程如下：
$git clone git://openflow.org/openflow.git
$cd openflow
$git checkout -b 1.0.0-netfpga origin/devel/tyabe/1.0.0-netfpga
$./boot.sh
$cd openflow
$./configure --enable-hw-lib=nf2
$make
$sudo make install

主要安裝了ofdatapath，ofprotocol等命令。

設(shè)置環(huán)境變量$cat /usr/local/netfpga/bashrc_addon >> ~/.bashrc? #將NetFPGA編譯用到的環(huán)境變量添加到當(dāng)前用戶中去$source ～/.bashrc$sudo /usr/local/netfpga/lib/scripts/grub_update/grub_update.sh?? #更新Grub$cd /usr/local/netfpga/lib/C/kernel/$make install$lsmod |grep nf2?????? #查看是否安裝了netfpga 內(nèi)核模塊如果沒有找到NetFPGA的內(nèi)核模塊$sudo /sbin/modprobe nf2.ko #安裝內(nèi)核模塊重啟機(jī)器。$/sbin/ifconfig????? #查看NetFPGA 4個端口的信息，以確認(rèn)NetFPGA package安裝成功。nf2c0 Link encap:Ethernet HWaddr 00:4E:46:32:43:00UP BROADCAST RUNNING PROMISC MULTICAST MTU:1986 Metric:1RX packets:0 errors:0 dropped:0 overruns:0 frame:0TX packets:0 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:1000RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)Interrupt:177nf2c1 Link encap:Ethernet HWaddr 00:4E:46:32:43:01UP BROADCAST RUNNING PROMISC MULTICAST MTU:1986 Metric:1RX packets:0 errors:0 dropped:0 overruns:0 frame:0TX packets:0 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:1000RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)Interrupt:177nf2c2 Link encap:Ethernet HWaddr 00:4E:46:32:43:02UP BROADCAST PROMISC MULTICAST MTU:1986 Metric:1RX packets:0 errors:0 dropped:0 overruns:0 frame:0TX packets:0 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:1000RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)Interrupt:177nf2c3 Link encap:Ethernet HWaddr 00:4E:46:32:43:03UP BROADCAST PROMISC MULTICAST MTU:1986 Metric:1RX packets:0 errors:0 dropped:0 overruns:0 frame:0TX packets:0 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:1000RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)Interrupt:177編譯生成bit文件(可選)編譯OpenFlow Switch bit文件其實很簡單。$ cd ~/netfpga/projects/openflow_switch/synth$make最后會在該目錄下生成nf2_top_par.bit搭建測試環(huán)境按照之前圖中所示網(wǎng)絡(luò)環(huán)境，進(jìn)行搭建。1. 設(shè)置PC1的千兆網(wǎng)卡，與NetFPGA nf2c0相連，并配置IP地址為10.0.0.2/242. 設(shè)置PC2的千兆網(wǎng)卡，與NetFPGA nf2c1相連，并配置IP地址為10.0.0.3/243. PC3是一臺虛擬機(jī)，需要與PC0進(jìn)行網(wǎng)絡(luò)通信。我們使用VirtualBox 鏡像，下載地址：運行OpenFlow Switch進(jìn)入PC0$sudo /usr/local/sbin/cpci_reprogram.pl –all???? #重置cpci$sudo nf_download /usr/local/netfpga/bitfiles/openflow_switch.bit? #下載openflow switch bit文件$sudo ofdatapath --detach punix:/var/run/dp0 -d 004E46324304 -i nf2c0,nf2c1,nf2c2,nf2c3 #設(shè)置openflow datapath$sudo ofprotocol unix:/var/run/dp0 tcp:192.168.10.106:6633????????? #與遠(yuǎn)程的controller進(jìn)行通信$sudo dpctl dump-flows unix:/var/run/dp0?????????????????????????????????????????? #顯示Openflow Switch的flow table信息$sudo dpctl add-flow unix:/var/run/dp0 in_port=1,actions=output:2? #添加flow，端口1進(jìn)來的數(shù)據(jù)發(fā)往端口2$sudo dpctl add-flow unix:/var/run/dp0 in_port=2,actions=output:1?? #添加flow，端口2進(jìn)來的數(shù)據(jù)發(fā)往端口1注：因為使用的reference controller， OpenFlow Switch中的flow-table是空的，可以在本地通過dpctl命令進(jìn)行手動添加規(guī)則。默認(rèn)每個flow的生命周期是60s，如果該端口沒有任何數(shù)據(jù)超過60s，該端口的規(guī)則會清空，發(fā)送/接受的數(shù)據(jù)回發(fā)給controller處理，直到有新的規(guī)則寫入，重新開始新的生命周期。進(jìn)入PC3，運行虛擬機(jī)鏡像，進(jìn)入Ubuntu11.1系統(tǒng)$sudo dhclinet eth2 #虛擬機(jī)自動獲取IP地址$controller ptcp:6633 #打開OpenFlow switch controller，開始監(jiān)聽6633端口信息。進(jìn)入PC2$ping 10.0.0.3進(jìn)入PC1，因為PC2裝了CentOS$ssh netfpga@10.0.0.3??? #PC1(10.0.0.2)通過SSH進(jìn)行連接PC2（10.0.0.3）如果有興趣查看一下OpenFlow Switch 與遠(yuǎn)程Controller，如何通信的，即OpenFlow protocol。需要安裝wireshark抓包工具，建議對照OpenFlow switch specification進(jìn)行學(xué)習(xí)。擴(kuò)展如果沒有NetFPGA做OpenFlow Switch，但是又想先常常鮮，怎么辦？你可以嘗試使用OpenFlow VSwitch，通過虛擬化來實現(xiàn)OpenFlow Switch。?是不是上面的一個OpenFlow 網(wǎng)絡(luò)環(huán)境可以由虛擬機(jī)來搭建完成？確實有的，僅能試玩！具體可以見參考資料中的OpenFlow Tutorial后話之前做的還只是個開始，路漫漫其修遠(yuǎn)兮！參考資料1. www.openflow.org3. Create OpenFlow network with multiple PCs/NetFPGAs4. OpenFlow Tutorial5.OpenFlow Switch Specification