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  • Start & Stop internet connexion without broking Network Manager

    - by user3634569
    I am on Precise. I used this command (with an alias), to close the network, dbus-send --system --print-reply --reply-timeout=120000 --type=method_call --dest=org.freedesktop.NetworkManager /org/freedesktop/NetworkManager org.freedesktop.NetworkManager stop it worked, now I have to use dbus-send --system --print-reply --reply-timeout=120000 --type=method_call --dest=org.freedesktop.NetworkManager /org/freedesktop/NetworkManager org.freedesktop.NetworkManager.Sleep boolean:true it work but not so well, sometimes I can't restart the network and NetworkManager is blocked too and strange errors even GUI freeze . What I need is a command line which close the network and don't mess with Network Manager, maybe with the routing table or what else.

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  • Ubuntu 12.10 no network and no graphics

    - by khasiKoMasu
    I recently upgraded Ubuntu 12.04 to 12.10 only to find out that it won't connect to any network, neither wired nor wireless and the graphics is messed up too as in a low screen resolution. For 12.04, my system was running perfectly. I don't know why upgrade messed it up so bad. Reinstalling the OS is an issue because I have set up a lot of development environments that I cannot afford to set it up again. Some of the outputs: lspci -nn | grep 0200 02:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller [10ec:8136] (rev 02) nm-tool NetworkManager Tool State: disconnected cat /etc/network/interfaces auto lo iface lo inet loopback sudo cat /var/log/syslog | grep etwork | tail -n20 Nov 2 13:50:22 Cobalt NetworkManager[978]: SCPlugin-Ifupdown: (-1240454760) ... get_connections (managed=false): return empty list. Nov 2 13:50:22 Cobalt NetworkManager[978]: Ifupdown: get unmanaged devices count: 0 Nov 2 13:50:22 Cobalt bluetoothd[1016]: Failed to init network plugin Nov 2 13:50:22 Cobalt NetworkManager[978]: <info> modem-manager is now available Nov 2 13:50:22 Cobalt NetworkManager[978]: <info> monitoring kernel firmware directory '/lib/firmware'. Nov 2 13:50:22 Cobalt NetworkManager[978]: <info> WiFi enabled by radio killswitch; enabled by state file Nov 2 13:50:22 Cobalt NetworkManager[978]: <info> WWAN enabled by radio killswitch; enabled by state file Nov 2 13:50:22 Cobalt NetworkManager[978]: <info> WiMAX enabled by radio killswitch; enabled by state file Nov 2 13:50:22 Cobalt NetworkManager[978]: <info> Networking is enabled by state file Nov 2 13:50:22 Cobalt NetworkManager[978]: <warn> /sys/devices/virtual/net/lo: couldn't determine device driver; ignoring... Nov 2 13:50:22 Cobalt NetworkManager[978]: <warn> /sys/devices/virtual/net/lo: couldn't determine device driver; ignoring... Nov 2 13:50:22 Cobalt NetworkManager[978]: <warn> bluez error getting default adapter: Message did not receive a reply (timeout by message bus) Nov 2 13:50:22 Cobalt NetworkManager[978]: <warn> bluez error getting default adapter: Message did not receive a reply (timeout by message bus) Nov 2 13:50:22 Cobalt kernel: [ 28.688167] type=1400 audit(1351882222.452:10): apparmor="STATUS" operation="profile_replace" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=1046 comm="apparmor_parser" Nov 2 13:50:22 Cobalt bluetoothd[1062]: Failed to init network plugin Nov 2 13:50:22 Cobalt NetworkManager[978]: <warn> bluez error getting default adapter: Message did not receive a reply (timeout by message bus) Nov 2 13:50:22 Cobalt bluetoothd[1118]: Failed to init network plugin Nov 2 13:50:22 Cobalt NetworkManager[978]: <warn> bluez error getting default adapter: Message did not receive a reply (timeout by message bus) Nov 2 13:50:22 Cobalt bluetoothd[1237]: Failed to init network plugin Nov 2 13:50:22 Cobalt NetworkManager[978]: <warn> bluez error getting default adapter: Message did not receive a reply (timeout by message bus) ps aux | grep -i network root 978 0.0 0.1 23732 4808 ? Ssl 13:50 0:00 NetworkManager sudo modprobe -r forcedeth FATAL: Module forcedeth not found

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  • Harvard vs. Von Neumann architecture

    - by user32569
    Hi. Our teacher told us, that Harvard architecture is the most evolved and produced architecture today and towards future. but I thing becouse os massive averhead of x86 and Von Neumann nased ARM systems that actually Von Neumann is the most used architecture today. Yes, MCUs with Harvard are even more produced, but since they all have just minor purpose (compared to x86 and ARM based) that Von Neumann is actually the one. Or is it really Harvard? And second, I know this is strange question, but does any architecture combining both exists? to have separate memory for data and programs, therefore faster instruction processing, but still able to work with these as Von Neumann? To be able o load amd unload programs to program memory on the fly? Isnt this the way the x86 should have go? Or would there be some bottleneck that pure Von neumann solves? Thanks.

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  • Virtual PC network connection setting issue

    - by George2
    Hello everyone, I am using Virtual PC 2007 on Windows Vista Enterprise x86. My confusion is about the network setting for guest OS. In the network setting, I can set the network adaptor of guest OS to one of my physical network adaptors of my host OS (I have tested that it works for guest OS to use the physical network adaptor of host OS to access external network). But in this way, 1. since both host OS and guest OS will use the same physical network adaptor, will there be any conflicts (e.g. same H/W serves two OS)? 2. will guest OS share a part of network bandwidth of the host OS of the physical network adaptor? 3. What means NAT setting in guest OS network connection adaptor? thanks in advance, George

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  • Building a Mac/PC Network in a Dorm with Network Restrictions

    - by user70340
    I have been a Windows XP user for the last few years, but I recently bought a 15'' MacBook Pro for research purposes. I would like to set up a no-hassle Mac/PC Network at home so that I can access the internet on both computers and hardware between computers (i.e. a harddrive, or a mouse/keyboard with Synergy). Unfortunately, I live in a dorm with silly network restrictions so a solution is not straightforward. In particular: The dorm has a wired and wireless network, both which provide an internet connection. The wired network provides way faster internet (download speeds of 15 MB/s vs. 2 MB/s on wireless), so I would like to somehow exploit this, at least on my PC for Bittorrent :) Multiple devices can connect to the wireless network, but cannot "see" each other on the network (so software like Synergy would not work). Only 1 MAC address can connect to the wired network at a time. Ideally I would just connect a wireless router to the wired network and then have both the Mac and the PC on that, but the 1 MAC address restriction will not allow the both computer to access the internet simultaneously. I cannot think of a way to bypass this restriction (though I'm not network savvy), so I am planning to create a private no-internet network to allow the devices to see each other and share hardware. Here are some thoughts. I would appreciate any feedback at all! If I build a private wireless network: (first choice) I will use a wireless router that is not connected to the internet. My PC and Mac will be connected to each other wirelessly. I can then connect the PC to the internet via a wired network, but then the Mac will not have internet access as its wireless card is already in use. In this case, could I stream internet access from the PC to the Mac via the wireless network? Or could I buy a USB wireless card for the Mac so that it can connect to both my private network and the dorm network? If I build a private wired network: (second choice) Then both the PC and the Mac will connect to the internet wirelessly, which means I cannot take advantage of the faster download speeds.

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  • Use Network-Manager to Connect to a wifi Access Point on the command-line

    - by Stefano Palazzo
    I'd like to connect to a wireless access point from the command-line. ideally, I'd only need the name of the AP. But the hardware-address would work as well. I know I can use nmcli to connect to a managed network connection, but in my case, the access point may not be configured for Network-Manager yet (See the difference between the output of nm-tool and nmcli con). Example output of nmcli: Auto pwln 3a3d62b1-bbdf-4f76-b4d2-c211fd5cfb03 802-11-wireless [...] Wired Network aa586921-accf-4932-98c4-c873c310f08e 802-3-ethernet [...] Cisco-UDP Uni 7f94847b-04dc-40b7-9955-5246fb77cc65 vpn [...] T-mobile (D1) 867f345a-cbbf-4bd4-b883-a5e5ae0932f0 gsm [...] Example output of nm-tool: State: connected - Device: eth1 [Auto pwln] ---------------------------------------------------- [...] Wireless Access Points (* = current AP) *pwln: Infra, [...], Freq 2472 MHz, Rate 54 Mb/s, Strength 80 WPA WPA2 WLAN: Infra, [...], Freq 2422 MHz, Rate 54 Mb/s, Strength 20 WPA WPA2 [...] How do I connect to an access point that may or may not be known to NM? Extra: Finding out if the connection needs a pass-phrase, and submitting it on the command-line as well would be great too (that is to say It'd be nice if network-manager wouldn't pop open any keyring dialogues or errors on the gui)

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  • Can't connect to hidden network with BCM4313

    - by poomerang
    The wireless works fine with all the other wi-fi nets I have tried, the only problem is with this hidden network. I should add it's the only hidden network I've tried, so I am not sure if the problem is it being hidden or somethings else, but I've checked the settings of NetworkManager against another Ubuntu system (which can connect) and they appear to be the same, passphrase included. The network is using WPA2 Personal with AES encryption, I don't know how to check this setting but I believe it's the usual for WPA2, and therefore usually not a problem. Also, I can connect through ethernet, which should exclude any blacklisting of my device, I believe. I usually use brcmsmac drivers, I've tried also STA but the result is the same. I've also tried the suggestion from Unable to connect to hidden SSID with no luck output of lspci -v is 03:00.0 Network controller: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller (rev 01) Subsystem: Askey Computer Corp. Device 7175 Flags: bus master, fast devsel, latency 0, IRQ 17 Memory at d4000000 (64-bit, non-prefetchable) [size=16K] Capabilities: <access denied> Kernel driver in use: brcmsmac Kernel modules: bcma, brcmsmac

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  • "Enable Wireless" option is disabled in network settings

    - by silenTK
    I'm using Ubuntu 11.10 (dual booted with Windows 7) but I'm unable to access Internet wireless even though I can do so on Windows 7. The output for rfkill list all is given below: rfkill list all 0: brcmwl-0: Wireless LAN Soft blocked: no Hard blocked: yes 1: hp-wifi: Wireless LAN Soft blocked: no Hard blocked: no The output for sudo lshw -C network *-network DISABLED is: description: Wireless interface product: BCM4313 802.11b/g/n Wireless LAN Controller vendor: Broadcom Corporation physical id: 0 bus info: pci@0000:02:00.0 logical name: eth1 version: 01 serial: 11:11:11:11:11:11 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=wl0 driverversion=5.100.82.38 latency=0 multicast=yes wireless=IEEE 802.11 resources: irq:16 memory:c2500000-c2503fff *-network description: Ethernet interface product: RTL8101E/RTL8102E PCI Express Fast Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:03:00.0 logical name: eth0 version: 05 serial: 22:22:22:22:22:22 size: 100Mbit/s capacity: 100Mbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl_nic/rtl8105e-1.fw latency=0 link=yes multicast=yes port=MII speed=100Mbit/s resources: irq:42 ioport:3000(size=256) memory:c0404000-c0404fff memory:c0400000-c0403fff Broadcom STA wireless driver is installed, activated, and currently in use. My laptop is a HP-Pavilion-g6-1004tx. My hardware switch is on. Enable Wireless option is also disabled in network settings.

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  • Ubuntu 12.04 on Vm Player showing Wired Network Instead of Wireless Network

    - by Fak365
    I am new to Ubuntu, recently I installed ubuntu 12.04 in Vm Player (Virtual Machine) on my Dell laptop having windows 7 ultimate 32 bit for just to check the security of my wireless network and want to crack the WiFi (WPA-PSK) password but in ubuntu it does not show the wireless network it shows the 2 arrow sign as i have not connect the ethernet cable to my laptop and connected through WiFi on my main OS (windows 7) but it shows the wired network and internet is working but it does not show wifi connection. On windows 7 WiFi is connected and showing the WiFi connection and working correctly.But my main motive is to crack the WiFi password as it can't detect WiFi network so what to do? Please Help.!!thanks My Laptop Specification : Laptop : Dell Latitude D620 OS : Windows 7 Ultimate 32 bit Processor : Core Duo 2 T7200 @ 2Ghz Ram : 2 GB WiFi card : Intel Pro/Wireless 3945 ABG Virtual Machine : Vm Player V 5.0.1 If Need to Install Drivers Please Give Me Full Information how to install and which driver I should install. Thanks In Advance.

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  • Cannot turn on "Network Discovery and File Sharing" when Windows Firewall is enabled

    - by Cheeso
    I have a problem similar to this one. Windows Firewall prevents File and Printer sharing from working and Why does File and Printer Sharing keep turning off in Windows 7? I cannot turn on Network Discovery. This is Windows 7 Home Premium, x64. It's a Dell XPS 1340 and Windows came installed from the OEM. This used to work. Now it doesn't. I don't know what has changed. In windows Explorer, the UI looks like this: When I click the yellow panel that says "Click to change...", the panel disappears, then immediately reappears, with exactly the same text. If I go through the control panel "Network and Sharing Center" thing, the UI looks like this: If I tick the box to "turn on network discovery", the "Save Changes" button becomes enabled. If I then click that button, the dialog box just closes, with no message or confirmation. Re-opening the same dialog box shows that Network Discovery has not been turned on. If I turn off Windows Firewall, I can then turn on Network Discovery via either method. The machine is connected to a wireless home network, via a router. The network is marked as "Home Network" in the Network and Sharing Center, which I think corresponds to the "Private" profile in Windows Firewall Advanced Settings app. (Confirm?) The PC is not part of a domain, and has never been part of a domain. The machine is not bridging any networks. There is a regular 100baseT connector but I have the network adapter for that disabled in Windows. Something else that seems odd. Within Windows Firewall Advanced Settings, there are no predefined rules available. If I click the "New Rule...." Action on the action pane, the "Predefined" option is greyed out. like this: In order to attempt to allow the network discovery protocols through on the private network, I hand-coded a bunch of rules, intending to allow the necessary UPnP and WDP protocols supporting network discovery. I copied them from a working Windows 7 Ultimate PC, running on the same network. This did not work. Even with the hand-coded rules, I still cannot turn on Network Discovery. I looked on the interwebs, and the only solution that appears to work is a re-install of Windows. Seriously? If I try netsh advfirewall firewall set rule group="Network Discovery" new enable=Yes ...it says "No rules match the specified criteria" EDIT: by the way, these services are running. DNS Client Function Discovery Resource Publication SSDP Discovery UPnP Device Host in any case, since it works with no firewall, I would assume all necessary services are present and running. The issue is a firewall thing, but I don't know how to diagnose further, or fix it. Q1: Is there a way to definitively insure the correct holes are punched through the Windows Firewall to allow Network Discovery to function? Q2: Should I expect the "predefined" firewall rules to be greyed out? Q3: Why did this change?

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  • Network config with pppoe and Ubuntu 13.10

    - by Pavel
    I have an internet connection that is using pppoe. In my windows I do not assign an ip address for my network and I am able to connect using password and username. I installed Ubintu 13.10 today, and I did pppoeconf, and I setup an ip/network mask and changed the mac address in the options, and I was able to connect to the Internet. I restarted the computer, and I got a message saying that the wired connection is not managed. Internet was not working. I went to network manager file, and I changed the option to true, but I still can't connect to the Internet. I am pretty new to linux. How can I get my Internet working? Thanks

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  • Connectify Dispatch: Link All Your Network Connections into a Super Pipeline

    - by Jason Fitzpatrick
    Connectify Dispatch is a network management tool that takes all the connections around you–Ethernet, Wi-Fi nodes, even 3G/4G cellular connections–and combines them into one giant data pipeline. At its most simple, Connectify Dispatch takes all the network inputs available to your computer (be those connections hard-line Ethernet, Wi-Fi nodes, or cellular connections) and merges the separate data connections seamlessly into one master connection. If any of the connections should falter (like your 3G reception goes out), Connectify automatically shifts the data to other available networks without any interruption. In addition you can specify which network Connectify should favor with connection prioritization; perfect for using your cellular connection without breaking through your data cap for the month right away. Hit up the link below to read more about Connectify Dispatch and the companion app Connectify Hotspot. Connectify Dispatch Secure Yourself by Using Two-Step Verification on These 16 Web Services How to Fix a Stuck Pixel on an LCD Monitor How to Factory Reset Your Android Phone or Tablet When It Won’t Boot

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  • Ubuntu Software Center not recognising my network connection

    - by Chethan S.
    I have installed Oneiric Beta on my laptop. As my Mobile Broadband refused to connect to Internet through network manager I'm now using wvdial to connect. Hence the network manager shows I'm not connected to any networks. When I try to install software from Ubuntu Software Center the 'Install' option remains disabled and under reviews section it says no network connection! As a workaround I kept installing applications from terminal which works fine. Therefore, my question is how to make Software Center recognize that I am connected to Internet?

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  • Which platform to choose, Java or .NET?

    - by salman
    I am working in a private bank, a leading mid size bank in local market. We are going to create our core banking solution. Existing solution has been developed on Java using IBM Visual Age 4.0. It is very important to discuss architecture first, we have currently more than 350 branches working in standalone mode, and it means they are working in self contained environment. They have their own database server (IBM DB2 9.7) and they are communicating with other branches via sockets to send and receive data. Having experience of .NET for more than 5 years I am trying to convince my superiors to choose .NET platform, but they are reluctant and unwilling. It is my job to encourage them for choosing best available platform to create large scale enterprise application. In simple word, we are going to create a very large scale enterprise financial application, a centralize and integrated which connects all branch networks plus having scalable, solid architecture that easily evolve over time. I want professional people to comment on above scenarios. Which platform to choose .NET or Java? Our all resource is currently working in Java, we have homogeneous environment (no Linux, no Mac and no UNIX). Any idea, any thoughts, any points technical or non-technical i.e. administrative or management point of view will be really appreciated.

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  • How to route my internet from mobile broadband from a third party software to network manager

    - by user86865
    I use mobile broadband connection (Reliance Netconnect+ USB) for internet. I can connect to this network from Network Manager easily. There is a 3rd party software which is given by the service provider. I can also connect to the internet by using this software (Software from ZTE). But when i am using this software, i cannot upload files to Ubuntu One, Cannot install packages from Software Center, etc except i can load web pages from FireFox. But when using the connection from NM, i can do all the stuffs. But, there are so many options available in this 3rd party software. So, can i route my internet connection from this software to my Network Manager? There are some options available in the settings as;- Dns, alternate dns, static IP, CHAP, PAP. Can anyone help me?? I use 12.04.

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  • Kubuntu won't go into suspend mode while connected to network

    - by PaulW2U
    I'm currently testing Kubuntu 11.04 but I don't think this is a bug regarding what I appreciate is still an alpha version. After extensive searching of various forums and websites I found something that made me suspect that the reason I could not go into suspend mode was due to the fact that my network connection was still active. I found that if I unmount my network connection then I can go into suspend mode without any problem. I then have to remember to mount the connection when I next use the PC. Am I missing a program or setting? Is there a config file that I can edit? How can I fix this so that my network connection is broken and remade at the appropriate time? I haven't found any indication that a bug has been reported relating to this. Thanks in advance.

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  • Diving into OpenStack Network Architecture - Part 1

    - by Ronen Kofman
    v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} rkofman Normal rkofman 83 3045 2014-05-23T21:11:00Z 2014-05-27T06:58:00Z 3 1883 10739 Oracle Corporation 89 25 12597 12.00 140 Clean Clean false false false false EN-US X-NONE HE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi; mso-bidi-language:AR-SA;} Before we begin OpenStack networking has very powerful capabilities but at the same time it is quite complicated. In this blog series we will review an existing OpenStack setup using the Oracle OpenStack Tech Preview and explain the different network components through use cases and examples. The goal is to show how the different pieces come together and provide a bigger picture view of the network architecture in OpenStack. This can be very helpful to users making their first steps in OpenStack or anyone wishes to understand how networking works in this environment.  We will go through the basics first and build the examples as we go. According to the recent Icehouse user survey and the one before it, Neutron with Open vSwitch plug-in is the most widely used network setup both in production and in POCs (in terms of number of customers) and so in this blog series we will analyze this specific OpenStack networking setup. As we know there are many options to setup OpenStack networking and while Neturon + Open vSwitch is the most popular setup there is no claim that it is either best or the most efficient option. Neutron + Open vSwitch is an example, one which provides a good starting point for anyone interested in understanding OpenStack networking. Even if you are using different kind of network setup such as different Neutron plug-in or even not using Neutron at all this will still be a good starting point to understand the network architecture in OpenStack. The setup we are using for the examples is the one used in the Oracle OpenStack Tech Preview. Installing it is simple and it would be helpful to have it as reference. In this setup we use eth2 on all servers for VM network, all VM traffic will be flowing through this interface.The Oracle OpenStack Tech Preview is using VLANs for L2 isolation to provide tenant and network isolation. The following diagram shows how we have configured our deployment: This first post is a bit long and will focus on some basic concepts in OpenStack networking. The components we will be discussing are Open vSwitch, network namespaces, Linux bridge and veth pairs. Note that this is not meant to be a comprehensive review of these components, it is meant to describe the component as much as needed to understand OpenStack network architecture. All the components described here can be further explored using other resources. Open vSwitch (OVS) In the Oracle OpenStack Tech Preview OVS is used to connect virtual machines to the physical port (in our case eth2) as shown in the deployment diagram. OVS contains bridges and ports, the OVS bridges are different from the Linux bridge (controlled by the brctl command) which are also used in this setup. To get started let’s view the OVS structure, use the following command: # ovs-vsctl show 7ec51567-ab42-49e8-906d-b854309c9edf     Bridge br-int         Port br-int             Interface br-int type: internal         Port "int-br-eth2"             Interface "int-br-eth2"     Bridge "br-eth2"         Port "br-eth2"             Interface "br-eth2" type: internal         Port "eth2"             Interface "eth2"         Port "phy-br-eth2"             Interface "phy-br-eth2" ovs_version: "1.11.0" We see a standard post deployment OVS on a compute node with two bridges and several ports hanging off of each of them. The example above is a compute node without any VMs, we can see that the physical port eth2 is connected to a bridge called “br-eth2”. We also see two ports "int-br-eth2" and "phy-br-eth2" which are actually a veth pair and form virtual wire between the two bridges, veth pairs are discussed later in this post. When a virtual machine is created a port is created on one the br-int bridge and this port is eventually connected to the virtual machine (we will discuss the exact connectivity later in the series). Here is how OVS looks after a VM was launched: # ovs-vsctl show efd98c87-dc62-422d-8f73-a68c2a14e73d     Bridge br-int         Port "int-br-eth2"             Interface "int-br-eth2"         Port br-int             Interface br-int type: internal         Port "qvocb64ea96-9f" tag: 1             Interface "qvocb64ea96-9f"     Bridge "br-eth2"         Port "phy-br-eth2"             Interface "phy-br-eth2"         Port "br-eth2"             Interface "br-eth2" type: internal         Port "eth2"             Interface "eth2" ovs_version: "1.11.0" Bridge "br-int" now has a new port "qvocb64ea96-9f" which connects to the VM and tagged with VLAN 1. Every VM which will be launched will add a port on the “br-int” bridge for every network interface the VM has. Another useful command on OVS is dump-flows for example: # ovs-ofctl dump-flows br-int NXST_FLOW reply (xid=0x4): cookie=0x0, duration=735.544s, table=0, n_packets=70, n_bytes=9976, idle_age=17, priority=3,in_port=1,dl_vlan=1000 actions=mod_vlan_vid:1,NORMAL cookie=0x0, duration=76679.786s, table=0, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=2,in_port=1 actions=drop cookie=0x0, duration=76681.36s, table=0, n_packets=68, n_bytes=7950, idle_age=17, hard_age=65534, priority=1 actions=NORMAL As we see the port which is connected to the VM has the VLAN tag 1. However the port on the VM network (eth2) will be using tag 1000. OVS is modifying the vlan as the packet flow from the VM to the physical interface. In OpenStack the Open vSwitch agent takes care of programming the flows in Open vSwitch so the users do not have to deal with this at all. If you wish to learn more about how to program the Open vSwitch you can read more about it at http://openvswitch.org looking at the documentation describing the ovs-ofctl command. Network Namespaces (netns) Network namespaces is a very cool Linux feature can be used for many purposes and is heavily used in OpenStack networking. Network namespaces are isolated containers which can hold a network configuration and is not seen from outside of the namespace. A network namespace can be used to encapsulate specific network functionality or provide a network service in isolation as well as simply help to organize a complicated network setup. Using the Oracle OpenStack Tech Preview we are using the latest Unbreakable Enterprise Kernel R3 (UEK3), this kernel provides a complete support for netns. Let's see how namespaces work through couple of examples to control network namespaces we use the ip netns command: Defining a new namespace: # ip netns add my-ns # ip netns list my-ns As mentioned the namespace is an isolated container, we can perform all the normal actions in the namespace context using the exec command for example running the ifconfig command: # ip netns exec my-ns ifconfig -a lo        Link encap:Local Loopback           LOOPBACK  MTU:16436 Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b) We can run every command in the namespace context, this is especially useful for debug using tcpdump command, we can ping or ssh or define iptables all within the namespace. Connecting the namespace to the outside world: There are various ways to connect into a namespaces and between namespaces we will focus on how this is done in OpenStack. OpenStack uses a combination of Open vSwitch and network namespaces. OVS defines the interfaces and then we can add those interfaces to namespace. So first let's add a bridge to OVS: # ovs-vsctl add-br my-bridge Now let's add a port on the OVS and make it internal: # ovs-vsctl add-port my-bridge my-port # ovs-vsctl set Interface my-port type=internal And let's connect it into the namespace: # ip link set my-port netns my-ns Looking inside the namespace: # ip netns exec my-ns ifconfig -a lo        Link encap:Local Loopback           LOOPBACK  MTU:65536 Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b) my-port   Link encap:Ethernet HWaddr 22:04:45:E2:85:21           BROADCAST  MTU:1500 Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b) Now we can add more ports to the OVS bridge and connect it to other namespaces or other device like physical interfaces. Neutron is using network namespaces to implement network services such as DCHP, routing, gateway, firewall, load balance and more. In the next post we will go into this in further details. Linux Bridge and veth pairs Linux bridge is used to connect the port from OVS to the VM. Every port goes from the OVS bridge to a Linux bridge and from there to the VM. The reason for using regular Linux bridges is for security groups’ enforcement. Security groups are implemented using iptables and iptables can only be applied to Linux bridges and not to OVS bridges. Veth pairs are used extensively throughout the network setup in OpenStack and are also a good tool to debug a network problem. Veth pairs are simply a virtual wire and so veths always come in pairs. Typically one side of the veth pair will connect to a bridge and the other side to another bridge or simply left as a usable interface. In this example we will create some veth pairs, connect them to bridges and test connectivity. This example is using regular Linux server and not an OpenStack node: Creating a veth pair, note that we define names for both ends: # ip link add veth0 type veth peer name veth1 # ifconfig -a . . veth0     Link encap:Ethernet HWaddr 5E:2C:E6:03:D0:17           BROADCAST MULTICAST  MTU:1500 Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b) veth1     Link encap:Ethernet HWaddr E6:B6:E2:6D:42:B8           BROADCAST MULTICAST  MTU:1500 Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b) . . To make the example more meaningful this we will create the following setup: veth0 => veth1 => br-eth3 => eth3 ======> eth2 on another Linux server br-eth3 – a regular Linux bridge which will be connected to veth1 and eth3 eth3 – a physical interface with no IP on it, connected to a private network eth2 – a physical interface on the remote Linux box connected to the private network and configured with the IP of 50.50.50.1 Once we create the setup we will ping 50.50.50.1 (the remote IP) through veth0 to test that the connection is up: # brctl addbr br-eth3 # brctl addif br-eth3 eth3 # brctl addif br-eth3 veth1 # brctl show bridge name     bridge id               STP enabled     interfaces br-eth3         8000.00505682e7f6       no              eth3                                                         veth1 # ifconfig veth0 50.50.50.50 # ping -I veth0 50.50.50.51 PING 50.50.50.51 (50.50.50.51) from 50.50.50.50 veth0: 56(84) bytes of data. 64 bytes from 50.50.50.51: icmp_seq=1 ttl=64 time=0.454 ms 64 bytes from 50.50.50.51: icmp_seq=2 ttl=64 time=0.298 ms When the naming is not as obvious as the previous example and we don't know who are the paired veth interfaces we can use the ethtool command to figure this out. The ethtool command returns an index we can look up using ip link command, for example: # ethtool -S veth1 NIC statistics: peer_ifindex: 12 # ip link . . 12: veth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 Summary That’s all for now, we quickly reviewed OVS, network namespaces, Linux bridges and veth pairs. These components are heavily used in the OpenStack network architecture we are exploring and understanding them well will be very useful when reviewing the different use cases. In the next post we will look at how the OpenStack network is laid out connecting the virtual machines to each other and to the external world. @RonenKofman

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  • Network is not working anymore - Ubuntu 12.04

    - by Jonathan
    Network is not working anymore - Ubuntu 12.04 Hello, I have a problem with my network connection. I have been using the same laptop with Ubuntu and the same connection for more than a year, and suddenly yesterday the connection stopped working (both wireless and wired). I've tested with another computer and the connection is fine (both wireless and wired). I've been reading similar posts but I haven't found a solution yet. I tried a few commands that I'm posting here (my system is in spanish, so I have traslated it to english, maybe the terms are not accurate): grep -i eth /var/log/syslog | tail Jun 3 18:45:40 vanesa-pc NetworkManager[3584]: (eth0): now managed Jun 3 18:45:40 vanesa-pc NetworkManager[3584]: (eth0): device state change: unmanaged - unavailable (reason 'managed') [10 20 2] Jun 3 18:45:40 vanesa-pc NetworkManager[3584]: (eth0): bringing up device. Jun 3 18:45:40 vanesa-pc NetworkManager[3584]: (eth0): preparing device. Jun 3 18:45:40 vanesa-pc kernel: [ 7351.845743] forcedeth 0000:00:0a.0: irq 41 for MSI/MSI-X Jun 3 18:45:40 vanesa-pc kernel: [ 7351.845984] forcedeth 0000:00:0a.0: eth0: no link during initialization Jun 3 18:45:40 vanesa-pc kernel: [ 7351.847103] ADDRCONF(NETDEV_UP): eth0: link is not ready Jun 3 18:45:40 vanesa-pc NetworkManager[3584]: (eth0): deactivating device (reason 'managed') [2] Jun 3 18:45:40 vanesa-pc NetworkManager[3584]: Added default wired connection 'Wired connection 1' for /sys/devices/pci0000:00/0000:00:0a.0/net/eth0 Jun 3 18:45:40 vanesa-pc kernel: [ 7351.848817] ADDRCONF(NETDEV_UP): eth0: link is not ready ifconfig -a eth0 Link encap:Ethernet addressHW 00:1b:24:fc:a8:d1 ACTIVE BROADCAST MULTICAST MTU:1500 Metric:1 Packages RX:0 errors:16 lost:0 overruns:0 frame:16 Packages TX:123 errors:0 lost:0 overruns:0 carrier:0 colissions:0 length.tailTX:1000 Bytes RX:0 (0.0 B) TX bytes:26335 (26.3 KB) Interruption:41 Base address: 0x2000 lo Link encap:Local loop Inet address:127.0.0.1 Mask:255.0.0.0 Inet6 address: ::1/128 Scope:Host ACTIVE LOOP WORKING MTU:16436 Metrics:1 Packages RX:1550 errors:0 lost:0 overruns:0 frame:0 Packages TX:1550 errors:0 lost:0 overruns:0 carrier:0 colissions:0 long.tailTX:0 Bytes RX:125312 (125.3 KB) TX bytes:125312 (125.3 KB) iwconfig lo no wireless extensions. eth0 no wireless extensions. sudo lshw -C network *-network description: Ethernet interface product: MCP67 Ethernet manufacturer: NVIDIA Corporation Physical id: a bus information: pci@0000:00:0a.0 logical name: eth0 version: a2 series: 00:1b:24:fc:a8:d1 capacity: 100Mbit/s width: 32 bits clock: 66MHz capacities: pm msi ht bus_master cap_list ethernet physical mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=forcedeth driverversion=0.64 latency=0 link=no maxlatency=20 mingnt=1 multicast=yes port=MII resources: irq:41 memoria:f6288000-f6288fff ioport:30f8(size=8) memoria:f6289c00-f6289cff memoria:f6289800-f628980f lsmod Module Size Used by usbhid 41906 0 hid 77367 1 usbhid rfcomm 38139 0 parport_pc 32114 0 ppdev 12849 0 bnep 17830 2 bluetooth 158438 10 rfcomm,bnep binfmt_misc 17292 1 joydev 17393 0 hp_wmi 13652 0 sparse_keymap 13658 1 hp_wmi nouveau 708198 3 ttm 65344 1 nouveau drm_kms_helper 45466 1 nouveau drm 197692 5 nouveau,ttm,drm_kms_helper i2c_algo_bit 13199 1 nouveau psmouse 87213 0 mxm_wmi 12859 1 nouveau serio_raw 13027 0 k8temp 12905 0 i2c_nforce2 12906 0 wmi 18744 2 hp_wmi,mxm_wmi video 19068 1 nouveau mac_hid 13077 0 lp 17455 0 parport 40930 3 parport_pc,ppdev,lp forcedeth 58096 0 Let me know if I can give you more information. Thank you very much in advance, Jonathan

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  • Enterprise vs Real time embedded systems

    - by JakeFisher
    In university I have 2 options for software architecture: Enterprise Real time embedded systems I would be very glad if someone can give me a brief explanation of what those are. I am interested in following criterias: Brief overview Complexity and interest. So does knowledge costs time? Area of usage Profit(salary) Working tools, programs. Might be some text editor, uml editor. Something else?

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  • How can I prioritize wireless networks with network-manager

    - by kynan
    Mostly I use my laptop in an environment where different wireless networks are available and I would like to preferably connect to one of those and only fall back to the other one if that one is not available. Is there any way of prioritizing which wireless networks network-manager preferably connects to? The only workaround I found so far was unchecking Connect Automatically in the options and re-enabling it when my preferred network is not available.

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  • Wireless network disabled

    - by neil delmonte
    After installing Ubuntu 11.04, my network has become disabled. Here is the output oflshw in terminal: *-network DISABLED description: Wireless interface product: BCM4312 802.11b/g LP-PHY vendor: Broadcom Corporation physical id: 0 bus info: pci@0000:02:00.0 logical name: eth1 version: 01 serial: 00:21:00:58:65:5f width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=wl0 driverversion=5.100.82.38 latency=0 multicast=yes wireless=IEEE 802.11bg resources: irq:17 memory:d4600000-d4603fff

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