錯誤排解¶

Mininet Cannot find required executable controller¶

if you get this problen

Cannot find required executable controller.
Please make sure that it is installed and available in your $PATH:
(/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin)

fix¶

sudo apt-get install openvswitch-testcontroller
sudo ln /usr/bin/ovs-testcontroller /usr/bin/controller 

source:https://stackoverflow.com/a/47312367

port衝突¶

在實驗時都在default設定之下,因為ryu啟動LISTEN的ip為0.0.0.0:6653

但是mininet 連線的位置為127.0.0.1:6653 所以無法連線

!!! bug bash Please shut down the controller which is running on port 6653

解決方案要確實指定正確ip

!!! fix bash sudo mn --controller=remote,ip=0.0.0.0,port=6653

miniedit版本問題¶

https://github.com/mininet/mininet/blob/master/examples/miniedit.py

目前miniedit.py只支援python2

啟動拓樸卡住¶

當卡在這裡 !!! bug bash *** Adding controller *** Add switches *** Add hosts *** Add links *** Starting network *** Configuring hosts h2 h1 *** Starting controllers *** Starting switches

解決方案¶

有可能是尚未啟動openvswitch

下這個指令 !!! fix sudo ovs-vswitchd

OVSDB連線問題¶

ovsdb-server 的啟動監聽位置要與OVSDB_ADDR 一樣

支援兩個地方控制db.sock與ptcp:6641

for manjaro

sudo ovsdb-server --remote=punix:/run/openvswitch/db.sock --remote=ptcp:6641 --pidfile=/run/openvswitch/ovsdb-server.pid

for ubuntu

sudo ovsdb-server --remote=punix:/usr/local/var/run/openvswitch/db.sock --remote=ptcp:6641 --pidfile

安裝ovs_vsctl

sudo pip3 install git+https://github.com/iwaseyusuke/python-ovs-vsctl.git

from ovs_vsctl import VSCtl
import time
vsctl = VSCtl('tcp', '127.0.0.1', 6641)
def close_port(datapath_id,port_id):
    try:
        popen = vsctl.run('del-port s'+str(datapath_id)+' s'+str(datapath_id)+'-eth'+str(port_id))
        return popen
    except:
        return False
def start_port(datapath_id,port_id):
    try:
        popen = vsctl.run('add-port s'+str(datapath_id)+' s'+str(datapath_id)+'-eth'+str(port_id)+' -- set Interface s'+str(datapath_id)+'-eth'+str(port_id)+' ofport_request='+str(port_id))
        return popen
    except:
        return False
close_port(33,1)
close_port(33,2)
time.sleep(10)
start_port(33,1)
start_port(33,2)

METER TABLE設定問題¶

!!! NOTE Open vSwitch有兩種用作模式核心(system)模式與user space(netdev)模式運作此模式需要安裝DPDK與編譯DPDK版本的Open vSwitch

datapath_types [netdev, system]

核心(system)¶

Open vSwitch 2.10才開始在核心(system)模式實做meter並且Linux kernel版本要高於4.15才支援meter table

http://docs.openvswitch.org/en/latest/faq/releases/

user space(netdev)¶

Open vSwitch 2.7開始在user space(netdev)實做meter,所以要使用必須安裝DPDK 使用DPDK+Open vSwitch可以讓user space(netdev)模式的Open vSwitch提高吞吐量

mininet要設定datapath為user才能使用user space轉發,

sudo mn --topo single,2 --switch ovs,protocols=OpenFlow13,datapath=user

執行時期錯誤¶

ryu由python撰寫的而線程是單核心,當你的拓樸規模過大會導致ryu的綠線程eventlet優先權或是排擠影響個別模塊功能.需要注意