Search Results

Search found 9758 results on 391 pages for 'wireless networking'.

Page 248/391 | < Previous Page | 244 245 246 247 248 249 250 251 252 253 254 255  | Next Page >

  • How does the socket API accept() function work?

    - by Eli Bendersky
    The socket API is the de-facto standard for TCP/IP and UDP/IP communications (that is, networking code as we know it). However, one of its core functions, accept() is a bit magical. To borrow a semi-formal definition: accept() is used on the server side. It accepts a received incoming attempt to create a new TCP connection from the remote client, and creates a new socket associated with the socket address pair of this connection. In other words, accept returns a new socket through which the server can communicate with the newly connected client. The old socket (on which accept was called) stays open, on the same port, listening for new connections. How does accept work? How is it implemented? There's a lot of confusion on this topic. Many people claim accept opens a new port and you communicate with the client through it. But this obviously isn't true, as no new port is opened. You actually can communicate through the same port with different clients, but how? When several threads call recv on the same port, how does the data know where to go? I guess it's something along the lines of the client's address being associated with a socket descriptor, and whenever data comes through recv it's routed to the correct socket, but I'm not sure. It'd be great to get a thorough explanation of the inner-workings of this mechanism.

    Read the article

  • Linux network stack : adding protocols with an LKM and dev_add_pack

    - by agent0range
    Hello, I have recently been trying to familiarize myself with the Linux Networking stack and device drivers (have both similarly named O'Reilly books) with the eventual goal of offloading UDP. I have already implemented UDP on the NIC but now the hard part... Rather than ask for assistance on this larger goal I was hoping someone could clarify for me a particular snippet I found that is part of a LKM which registeres a new protocol (OTP) that acts as a filter between the device driver and network stack. http://www.phrack.org/archives/55/p55_0x0c_Building%20Into%20The%20Linux%20Network%20Layer_by_lifeline%20&%20kossak.txt (Note: this Phrack article contains three different modules, code for the OTP is at the bottom of the page) In the init function of his example he has: otp_proto.type = htons(ETH_P_ALL); otp_proto.func = otp_func; dev_add_pack(&otp_proto); which (if I understand correctly) should register otp_proto as a packet sniffer and put it into the ptype_all data structure. My question is about the dev_add_pack. Is it the case that the protocol being registered as a filter will always be placed at this layer between L2 and the device driver? Or, for instance could I make such a filtering occur between the application and transport layers (analyze socket parameters) using the same process? I apologize if this is confusing - I am having some trouble wrapping my head around the bigger picture when it comes to modules altering kernel stack functionality. Thanks

    Read the article

  • java.net.BindException How can I clear the sockets or what ever is causing it?

    - by user2266067
    I need some help with, I guess a simple networking related problem I'm having. It will also help me better understand how all this works by knowing what isn't being .close()'ed. I'm sure this is pretty simple, but for me its all very new. This is the client program. I can most likely append the server then, if I can figure this out. Thanks public class Server { public static void main(String[] args) { start(); } static int start = 0; public static void start() { try { ServerSocket serverSocket = new ServerSocket(4567); Socket socket = serverSocket.accept(); //1) Take and echo input (In this case a message) BufferedReader bf = new BufferedReader(new InputStreamReader(socket.getInputStream())); String message = bf.readLine(); System.out.println("Message recieved from Client:" + message); //2) Response of client message PrintWriter printWriter = new PrintWriter(socket.getOutputStream(), true); printWriter.println("Server echoing back the message ' " + message + " ' from Client"); } catch (IOException e) { System.out.println("e " + e); System.exit(-1); } start++; clearUp(); if (start < 5) { System.out.println("Closing binds and Restarting" + start); start(); } } public void clearUp(){ //How would I clear the stuff that is left bound so I can restart via start() and avoid the java.net.BindException: Address already in use: JVM_Bind ? } } How would I clear the stuff that is left bound so I can restart via start() and avoid java.net.BindException: Address already in use: JVM_Bind ?

    Read the article

  • Where are possible locations of queueing/buffering delays in Linux multicast?

    - by Matt
    We make heavy use of multicasting messaging across many Linux servers on a LAN. We are seeing a lot of delays. We basically send an enormous number of small packages. We are more concerned with latency than throughput. The machines are all modern, multi-core (at least four, generally eight, 16 if you count hyperthreading) machines, always with a load of 2.0 or less, usually with a load less than 1.0. The networking hardware is also under 50% capacity. The delays we see look like queueing delays: the packets will quickly start increasing in latency, until it looks like they jam up, then return back to normal. The messaging structure is basically this: in the "sending thread", pull messages from a queue, add a timestamp (using gettimeofday()), then call send(). The receiving program receives the message, timestamps the receive time, and pushes it in a queue. In a separate thread, the queue is processed, analyzing the difference between sending and receiving timestamps. (Note that our internal queues are not part of the problem, since the timestamps are added outside of our internal queuing.) We don't really know where to start looking for an answer to this problem. We're not familiar with Linux internals. Our suspicion is that the kernel is queuing or buffering the packets, either on the send side or the receive side (or both). But we don't know how to track this down and trace it. For what it's worth, we're using CentOS 4.x (RHEL kernel 2.6.9).

    Read the article

  • Cannot bind to IPv6 address

    - by ereOn
    I am facing a strange problem on my Ubuntu Karmic system. When I call getaddrinfo() with AI_PASSIVE and AF_UNSPEC, for an empty host and the UDP 12000 port to get a bindable address, I only get back one IPv4 result (0.0.0.0:12000 for instance). If I change my call and specify AF_INET6 instead of AF_UNSPEC, then getaddrinfo() returns "Name or service not known". Shouldn't I get [::]:12000 as a result ? The same thing happens if I set the host to ::1. When I call getaddrinfo() without AI_PASSIVE (to get a "connectable" address) for the host "localhost" and the UDP 12000 port, I first get [::1]:12000 then 127.0.0.1:12000. So apparently, my system is IPv6 ready (I can ping to both IPv4 and IPv6 addresses, as well as DNS resolution). But how is it that I can't get an IPv6 address to bind to with getaddrinfo() ? Do you guys have any idea about what could be wrong ? My OS is Ubuntu Karmic, fresh install without any networking tweaking. Thank you.

    Read the article

  • Socket stops communicating

    - by user1392992
    I'm running python 2.7 code on a Raspberry Pi that receives serial data from an Arduino, processes it, and sends it to a Windows box over a wifi link. The Pi is wired to a Linksys router running in client bridge mode and that router connects over wifi to another Linksys router to which the Windows box is wired. The code in the Pi runs fine for some (apparently) random interval, and then the Pi becomes unreachable from the Windows box. I'm running PUTTY on the the Windows machine to connect to the Pi and when the fail occurs I get a message saying there's been a network error and the Pi is not reachable. Pinging the Pi from the Windows machine works fine until the error, at which time it produces "Reply from 192.168.0.129: Destination host unreachable." The client bridge router to which the Pi is connected remains reachable. I've got the networking code on the Pi wrapped in an exception handler, and when it fails it shows the following: Ethernet problem: Traceback (most recent call last): File "garage.py", line 108, in module s.connect((host, port)) File "/usr/lib/python2.7/socket.py", line 224, in meth return getattr(self._sock,name)(*args) error: [Errno 113] No route to host None The relevant python code looks like: import socket import traceback host = '192.168.0.129' port = 31415 in the setup, and after serial data has been processed: try: bline = strline.encode('utf-8') s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((host, port)) s.send(bline) s.close() except: print "Ethernet problem: " print traceback.print_exc() Where strline contains the processed data. As I said, this runs fine for a few hours more or less before failing. Any ideas? EDIT: When PUTTY fails its error message is :Network Error: Software caused connection abort."

    Read the article

  • Xsigo and Oracle's Storage

    - by Philippe Deverchère
    Xsigo, a virtual network infrastructure provider, has recently been acquired by Oracle. Following this acquisition, one might ask ourselves why it is important to Oracle and how Oracle's storage is going to benefit on the long term from this virtualized infrastructure layer. Well, the first thing to understand is that Virtual Networking addresses both network and storage connectivity. Oracle Virtual Networking, as the Xsigo technology is now called, connects any server to any network and storage, so this is not just about connecting servers to the Internet or Intranet. It is also for a large part connecting servers to NAS and SAN storage. Connecting servers to storage has become increasingly complex in the past few years because of the strong emergence of virtualization at the Operating System level. 50% of enterprise workloads are now virtualized, up from 18% in 2009, resulting in a strong consolidation of various applications in a high density server footprint. At the same time, server I/O capability increased 8x in the last 8 years. All this has pushed IT administrators to multiply the number of I/O connections in the back-end of their physical servers, resulting in a messy and very hard to manage networking infrastructure. Here is a typical view of a rack back-end when no virtual networking is used. We consider that today: - 75% of users have ten or more Ethernet ports per server - 85% of users have two or more SAN ports per server - 58% have had to add connectivity to a server specifically for VMs - 65% consider cable reduction a priority The average is 12 or more ports per server, resulting in an extremely complex infrastructure to manage. What Oracle wants to achieve with its Oracle Virtual Networking offering is pretty simple. The objective is to eliminate the complexity through a dramatic reduction of cabling between servers and storage/networks. It is also to provide a software based management system so that any server can be connected to any network or any storage, on demand, and without physical intervention on the infrastructure. At the end of the day, the picture on the left shows what one wants to get for the back-end of customer's racks: just a couple of connections on each physical server to provide a simple, agile and fast network infrastructure for both storage and networking access. This is exactly what the Oracle Virtual Networking solution does. It transforms a complex, error-prone, difficult to manage and expensive networking infrastructure into a simple, high performance and agile solution for the data center. Practically speaking, and for the sake of simplicity, imagine that each server just hosts a minimal number of physical InfiniBand HCAs (Host Channel Adapter) with two links (for redundancy) onto the Oracle Fabric Interconnect director. Using the Oracle Fabric Manager software, you'll then be able to create virtual NICs and HBAs (called vNIC and vHBA) that will be seen by the servers as standard NICs and HBAs and associate them to networks and storage systems which are physically connected to the back-end of the director through standard Fibre Channel and Ethernet GbE/10GbE ports. In addition to this incredibly simple "at-a-click" connectivity capability, the Oracle Virtual Networking solution offers powerful features such as network isolation, Quality of Service, advanced performance monitoring and non-disruptive reconfiguration, migration and scalability of networking infrastructure. So let's go back now to our initial question: why is Oracle Virtual Networking especially important to Oracle's storage solutions? After all, one could connect any storage in the back-end of the Oracle Fabric Interconnect directors, right? The answer is pretty simple: since Oracle owns both the virtualized networking infrastructure and the storage (ZFS-SA, Pillar Axiom and tape), it is possible to imagine several ways in the future to add value when it comes to connect storage to a virtualized storage network: enhanced storage capabilities, converged management between storage and network, improved diagnostic capabilities and optimized integration resulting in higher performance and unique features/functions. Of course, all this is not going to be done overnight, and future will tell us is which evolutions come first. But there is little doubt that the integration of Xsigo within Oracle is going to create opportunities for Oracle's storage!

    Read the article

  • What are these errors when I try to "make" the driver of my wireless adapter?

    - by Tom Brito
    I got got a wireless to usb adapter, and I'm having some trouble to install the drivers on Ubuntu. First of all, the readme says to use the make command, and I already got errors: $ make make[1]: Entering directory `/usr/src/linux-headers-2.6.35-22-generic' CC [M] /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.o /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c: In function ‘rtl8192_usb_probe’: /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12325: error: ‘struct net_device’ has no member named ‘open’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12326: error: ‘struct net_device’ has no member named ‘stop’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12327: error: ‘struct net_device’ has no member named ‘tx_timeout’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12328: error: ‘struct net_device’ has no member named ‘do_ioctl’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12329: error: ‘struct net_device’ has no member named ‘set_multicast_list’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12330: error: ‘struct net_device’ has no member named ‘set_mac_address’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12331: error: ‘struct net_device’ has no member named ‘get_stats’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12332: error: ‘struct net_device’ has no member named ‘hard_start_xmit’ make[2]: *** [/home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.o] Error 1 make[1]: *** [_module_/home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u] Error 2 make[1]: Leaving directory `/usr/src/linux-headers-2.6.35-22-generic' make: *** [all] Error 2 /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/ is the path where I copied the drivers on my computer. Any idea how to solve this? (I don't even know what the error is...) update: sudo lshw -class network *-network description: Ethernet interface product: RTL8111/8168B PCI Express Gigabit Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:01:00.0 logical name: eth0 version: 03 serial: 78:e3:b5:e7:5f:6e size: 10MB/s capacity: 1GB/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half latency=0 link=no multicast=yes port=MII speed=10MB/s resources: irq:42 ioport:d800(size=256) memory:fbeff000-fbefffff memory:faffc000-faffffff memory:fbec0000-fbedffff *-network DISABLED description: Wireless interface physical id: 2 logical name: wlan0 serial: 00:26:18:a1:ae:64 capabilities: ethernet physical wireless configuration: broadcast=yes multicast=yes wireless=802.11b/g

    Read the article

  • What are these errors when I try to "make" the driver of my wireless network?

    - by Tom Brito
    I got got a wireless to usb adapter, and I'm having some trouble to install the drivers on Ubuntu. First of all, the readme file say to use the "make" command, and I already got errors: $ make make[1]: Entering directory `/usr/src/linux-headers-2.6.35-22-generic' CC [M] /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.o /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c: In function ‘rtl8192_usb_probe’: /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12325: error: ‘struct net_device’ has no member named ‘open’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12326: error: ‘struct net_device’ has no member named ‘stop’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12327: error: ‘struct net_device’ has no member named ‘tx_timeout’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12328: error: ‘struct net_device’ has no member named ‘do_ioctl’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12329: error: ‘struct net_device’ has no member named ‘set_multicast_list’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12330: error: ‘struct net_device’ has no member named ‘set_mac_address’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12331: error: ‘struct net_device’ has no member named ‘get_stats’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12332: error: ‘struct net_device’ has no member named ‘hard_start_xmit’ make[2]: *** [/home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.o] Error 1 make[1]: *** [_module_/home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u] Error 2 make[1]: Leaving directory `/usr/src/linux-headers-2.6.35-22-generic' make: *** [all] Error 2 /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/ is the path where I copied the drivers on my computer. Any idea how to solve this? (I don't even know what the error is...) update: sudo lshw -class network *-network description: Ethernet interface product: RTL8111/8168B PCI Express Gigabit Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:01:00.0 logical name: eth0 version: 03 serial: 78:e3:b5:e7:5f:6e size: 10MB/s capacity: 1GB/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half latency=0 link=no multicast=yes port=MII speed=10MB/s resources: irq:42 ioport:d800(size=256) memory:fbeff000-fbefffff memory:faffc000-faffffff memory:fbec0000-fbedffff *-network DISABLED description: Wireless interface physical id: 2 logical name: wlan0 serial: 00:26:18:a1:ae:64 capabilities: ethernet physical wireless configuration: broadcast=yes multicast=yes wireless=802.11b/g

    Read the article

  • UDP sockets in ad hoc network (Ubuntu 9.10)

    - by Ekhiotz
    Hi! I am using BSD sockets in Ubuntu 9.10 to send UDP packets in broadcast with the following code: sock_fd = socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP); //sock_fd=socket(AF_INET,SOCK_DGRAM,0); receiver_addr.sin_family = PF_INET; //does not send with broadcast in ad hoc receiver_addr.sin_addr.s_addr = htonl(INADDR_BROADCAST); inet_aton("169.254.255.255",&receiver_addr.sin_addr); receiver_addr.sin_port = htons(port); int broadcast = 1; // this call is what allows broadcast packets to be sent: if (setsockopt(sock_fd, SOL_SOCKET, SO_BROADCAST, &broadcast, sizeof broadcast) == -1) { perror("setsockopt (SO_BROADCAST)"); exit(1); } ret=sendto(sock_fd, packet, size, 0,(struct sockaddr*)&receiver_addr,sizeof(receiver_addr)); Note that is not all the code, it is only to have an idea. The program sends all the data with INADDR_BROADCAST if I am connected to an infrastructure wireless network. However, if my laptop is connected to an ad-hoc network, it is able to receive all the data, but not to send it. I have solved the problem using the 169.254.255.255 broadcast address, but I would like to know what is going on. Thank you in advance!

    Read the article

  • Local Network - Windows 7 and Vista can't see each other

    - by ca8msm
    I've got a strange issue at home that has been bugging me for weeks, but I really need to get it sorted now so I'll detail as much as I can and hopefully someone can spot what might might be wrong. I have a wireless router connected to the internet and 3 devices connected to it. They are: Name OS Network IPv4 PC1 Windows 7 WORKGROUP 192.168.2.2 LAPTOP1 Vista WORKGROUP 192.168.2.3 PS3 192.168.2.4 and they all get their IP addresses dynamically. Both PC1 and LAPTOP1 can ping PS3 and get a response. PC1 and LAPTOP1 are unable to ping each other by ip address unless I ping by their name (which bizarrely shows that it is pinging via the IPv6 address). Also, to confirm this both PC1 and LAPTOP1 can ping each other via the long IPv6 address that they both have so they can obviously see each other just not via IPv4. I've disabled the firewalls on both machines as well to rule that out. I don't really know what IPv6 is used for and I've tried disabling it on both machines but all that happens then is that neither machine can see each other at all then. Does anyone have any idea of what may be stopping them seeing each other, any ways I can look at fixing this, or any network tools that may help identify where it is failing? Thanks, Mark

    Read the article

  • A two player game over the intranet..

    - by Santwana
    Hi everybody.. I am a student of 3rd year engineering and only a novice in my programming skills. I need some help with my project.. I wish to develop a two player game to be played over the network (Intranet). I want to develop a simple website with a few html pages for this.My ideas for the project run as follows: 1.People can log in from different systems and check who ever is online on the network currently. the page also shows who is playing with whom. 2.If a person is interested in playing with a player who is currently online, he sends a request of which the other player is somehow notified( using a message or an alert on his profile page..) 3.If the player accepts the request, a game is started. This is exactly where I am clueless.. How can I make them play the game? I need to develop a turn based game with two players, eg chessboard.. how can I do this? The game has to be played live.. and it is time tracked. i need your help with coding the above.. the other features i wish to include are: 4.The game could not be abruptly terminated by any one if the users.The request to terminate the game should be sent to the other player first and only if he accepts can the game be terminated. Whoever wins the game would get a plus 10 on their credit and if he terminated he gets a minus 10. The credits remains constant even if he loses but the success percentage is reduced. 6.The player with highest winning percentage is projected as the player of the week on the home page and he can post a challenge to all others.. I only have an intermediate knowledge of core java and know the basics of Swing and Awt. I am not at all familiar with networking in java right now. I have 5 to 6 weeks of time for developing the project but I hope to learn the things before I start my project. i would prefer to use a lan to illustrate the project and I know only java,jsp,oracle,html and bit of xml to develop my proj. Also I wish to know if I can code this within 6 weeks, would it be too difficult or complicated? Please spare some time to tell me. Please.. please.. I need your suggestions and help.. thank you so much..

    Read the article

  • [Wireless LAN]hostapd is giving error whwn running in target board

    - by Renjith G
    hi, I got the following error when i tried to run the hostapd command in my target board. Any idea about this? /etc # hostapd -dd hostapd.conf Configuration file: hostapd.conf madwifi_set_iface_flags: dev_up=0 madwifi_set_privacy: enabled=0 BSS count 1, BSSID mask ff:ff:ff:ff:ff:ff (0 bits) Flushing old station entries madwifi_sta_deauth: addr=ff:ff:ff:ff:ff:ff reason_code=3 ioctl[IEEE80211_IOCTL_SETMLME]: Invalid argument madwifi_sta_deauth: Failed to deauth STA (addr ff:ff:ff:ff:ff:ff reason 3) Could not connect to kernel driver. Deauthenticate all stations madwifi_sta_deauth: addr=ff:ff:ff:ff:ff:ff reason_code=2 ioctl[IEEE80211_IOCTL_SETMLME]: Invalid argument madwifi_sta_deauth: Failed to deauth STA (addr ff:ff:ff:ff:ff:ff reason 2) madwifi_set_privacy: enabled=0 madwifi_del_key: addr=00:00:00:00:00:00 key_idx=0 madwifi_del_key: addr=00:00:00:00:00:00 key_idx=1 madwifi_del_key: addr=00:00:00:00:00:00 key_idx=2 madwifi_del_key: addr=00:00:00:00:00:00 key_idx=3 Using interface ath0 with hwaddr 00:0b:6b:33:8c:30 and ssid '"RG_WLAN Testing Renjith G"' SSID - hexdump_ascii(len=27): 22 52 47 5f 57 4c 41 4e 20 54 65 73 74 69 6e 67 "RG_WLAN Testing 20 52 65 6e 6a 69 74 68 20 47 22 Renjith G" PSK (ASCII passphrase) - hexdump_ascii(len=12): 6d 79 70 61 73 73 70 68 72 61 73 65 mypassphrase PSK (from passphrase) - hexdump(len=32): 70 6f a6 92 da 9c a8 3b ff 36 85 76 f3 11 9c 5e 5d 4a 4b 79 f4 4e 18 f6 b1 b8 09 af 6c 9c 6c 21 madwifi_set_ieee8021x: enabled=1 madwifi_configure_wpa: group key cipher=1 madwifi_configure_wpa: pairwise key ciphers=0xa madwifi_configure_wpa: key management algorithms=0x2 madwifi_configure_wpa: rsn capabilities=0x0 madwifi_configure_wpa: enable WPA=0x1 WPA: group state machine entering state GTK_INIT (VLAN-ID 0) GMK - hexdump(len=32): [REMOVED] GTK - hexdump(len=32): [REMOVED] WPA: group state machine entering state SETKEYSDONE (VLAN-ID 0) madwifi_set_key: alg=TKIP addr=00:00:00:00:00:00 key_idx=1 madwifi_set_privacy: enabled=1 madwifi_set_iface_flags: dev_up=1 ath0: Setup of interface done. l2_packet_receive - recvfrom: Network is down Wireless event: cmd=0x8b1a len=40 Register Fail Register Fail WPA: group state machine entering state SETKEYS (VLAN-ID 0) GMK - hexdump(len=32): [REMOVED] GTK - hexdump(len=32): [REMOVED] wpa_group_setkeys: GKeyDoneStations=0 WPA: group state machine entering state SETKEYSDONE (VLAN-ID 0) madwifi_set_key: alg=TKIP addr=00:00:00:00:00:00 key_idx=2 Signal 2 received - terminating Flushing old station entries madwifi_sta_deauth: addr=ff:ff:ff:ff:ff:ff reason_code=3 ioctl[IEEE80211_IOCTL_SETMLME]: Invalid argument madwifi_sta_deauth: Failed to deauth STA (addr ff:ff:ff:ff:ff:ff reason 3) Could not connect to kernel driver. Deauthenticate all stations madwifi_sta_deauth: addr=ff:ff:ff:ff:ff:ff reason_code=2 ioctl[IEEE80211_IOCTL_SETMLME]: Invalid argument madwifi_sta_deauth: Failed to deauth STA (addr ff:ff:ff:ff:ff:ff reason 2) madwifi_set_privacy: enabled=0 madwifi_set_ieee8021x: enabled=0 madwifi_set_iface_flags: dev_up=0

    Read the article

  • SqlBulkCopy is slow, doesn't utilize full network speed

    - by Alex
    Hi, for that past couple of weeks I have been creating generic script that is able to copy databases. The goal is to be able to specify any database on some server and copy it to some other location, and it should only copy the specified content. The exact content to be copied over is specified in a configuration file. This script is going to be used on some 10 different databases and run weekly. And in the end we are copying only about 3%-20% of databases which are as large as 500GB. I have been using the SMO assemblies to achieve this. This is my first time working with SMO and it took a while to create generic way to copy the schema objects, filegroups ...etc. (Actually helped find some bad stored procs). Overall I have a working script which is lacking on performance (and at times times out) and was hoping you guys would be able to help. When executing the WriteToServer command to copy large amount of data ( 6GB) it reaches my timeout period of 1hr. Here is the core code for copying table data. The script is written in PowerShell. $query = ("SELECT * FROM $selectedTable " + $global:selectiveTables.Get_Item($selectedTable)).Trim() Write-LogOutput "Copying $selectedTable : '$query'" $cmd = New-Object Data.SqlClient.SqlCommand -argumentList $query, $source $cmd.CommandTimeout = 120; $bulkData = ([Data.SqlClient.SqlBulkCopy]$destination) $bulkData.DestinationTableName = $selectedTable; $bulkData.BulkCopyTimeout = $global:tableCopyDataTimeout # = 3600 $reader = $cmd.ExecuteReader(); $bulkData.WriteToServer($reader); # Takes forever here on large tables The source and target databases are located on different servers so I kept track of the network speed as well. The network utilization never went over 1% which was quite surprising to me. But when I just transfer some large files between the servers, the network utilization spikes up to 10%. I have tried setting the $bulkData.BatchSize to 5000 but nothing really changed. Increasing the BulkCopyTimeout to an even greater amount would only solve the timeout. I really would like to know why the network is not being used fully. Anyone else had this problem? Any suggestions on networking or bulk copy will be appreciated. And please let me know if you need more information. Thanks. UPDATE I have tweaked several options that increase the performance of SqlBulkCopy, such as setting the transaction logging to simple and providing a table lock to SqlBulkCopy instead of the default row lock. Also some tables are better optimized for certain batch sizes. Overall, the duration of the copy was decreased by some 15%. And what we will do is execute the copy of each database simultaneously on different servers. But I am still having a timeout issue when copying one of the databases. When copying one of the larger databases, there is a table for which I consistently get the following exception: System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. It is thrown about 16 after it starts copying the table which is no where near my BulkCopyTimeout. Even though I get the exception that table is fully copied in the end. Also, if I truncate that table and restart my process for that table only, the tables is copied over without any issues. But going through the process of copying that entire database fails always for that one table. I have tried executing the entire process and reseting the connection before copying that faulty table, but it still errored out. My SqlBulkCopy and Reader are closed after each table. Any suggestions as to what else could be causing the script to fail at the point each time?

    Read the article

  • Security review of an authenticated Diffie Hellman variant

    - by mtraut
    EDIT I'm still hoping for some advice on this, i tried to clarify my intentions... When i came upon device pairing in my mobile communication framework i studied a lot of papers on this topic and and also got some input from previous questions here. But, i didn't find a ready to implement protocol solution - so i invented a derivate and as i'm no crypto geek i'm not sure about the security caveats of the final solution: The main questions are Is SHA256 sufficient as a commit function? Is the addition of the shared secret as an authentication info in the commit string safe? What is the overall security of the 1024 bit group DH I assume at most 2^-24 bit probability of succesful MITM attack (because of 24 bit challenge). Is this plausible? What may be the most promising attack (besides ripping the device out off my numb, cold hands) This is the algorithm sketch For first time pairing, a solution proposed in "Key agreement in peer-to-peer wireless networks" (DH-SC) is implemented. I based it on a commitment derived from: A fix "UUID" for the communicating entity/role (128 bit, sent at protocol start, before commitment) The public DH key (192 bit private key, based on the 1024 bit Oakley group) A 24 bit random challenge Commit is computed using SHA256 c = sha256( UUID || DH pub || Chall) Both parties exchange this commitment, open and transfer the plain content of the above values. The 24 bit random is displayed to the user for manual authentication DH session key (128 bytes, see above) is computed When the user opts for persistent pairing, the session key is stored with the remote UUID as a shared secret Next time devices connect, commit is computed by additionally hashing the previous DH session key before the random challenge. For sure it is not transfered when opening. c = sha256( UUID || DH pub || DH sess || Chall) Now the user is not bothered authenticating when the local party can derive the same commitment using his own, stored previous DH session key. After succesful connection the new DH session key becomes the new shared secret. As this does not exactly fit the protocols i found so far (and as such their security proofs), i'd be very interested to get an opinion from some more crypto enabled guys here. BTW. i did read about the "EKE" protocol, but i'm not sure what the extra security level is.

    Read the article

  • non blocking client server chat application in java using nio

    - by Amith
    I built a simple chat application using nio channels. I am very much new to networking as well as threads. This application is for communicating with server (Server / Client chat application). My problem is that multiple clients are not supported by the server. How do I solve this problem? What's the bug in my code? public class Clientcore extends Thread { SelectionKey selkey=null; Selector sckt_manager=null; public void coreClient() { System.out.println("please enter the text"); BufferedReader stdin=new BufferedReader(new InputStreamReader(System.in)); SocketChannel sc = null; try { sc = SocketChannel.open(); sc.configureBlocking(false); sc.connect(new InetSocketAddress(8888)); int i=0; while (!sc.finishConnect()) { } for(int ii=0;ii>-22;ii++) { System.out.println("Enter the text"); String HELLO_REQUEST =stdin.readLine().toString(); if(HELLO_REQUEST.equalsIgnoreCase("end")) { break; } System.out.println("Sending a request to HelloServer"); ByteBuffer buffer = ByteBuffer.wrap(HELLO_REQUEST.getBytes()); sc.write(buffer); } } catch (IOException e) { e.printStackTrace(); } finally { if (sc != null) { try { sc.close(); } catch (Exception e) { e.printStackTrace(); } } } } public void run() { try { coreClient(); } catch(Exception ej) { ej.printStackTrace(); }}} public class ServerCore extends Thread { SelectionKey selkey=null; Selector sckt_manager=null; public void run() { try { coreServer(); } catch(Exception ej) { ej.printStackTrace(); } } private void coreServer() { try { ServerSocketChannel ssc = ServerSocketChannel.open(); try { ssc.socket().bind(new InetSocketAddress(8888)); while (true) { sckt_manager=SelectorProvider.provider().openSelector(); ssc.configureBlocking(false); SocketChannel sc = ssc.accept(); register_server(ssc,SelectionKey.OP_ACCEPT); if (sc == null) { } else { System.out.println("Received an incoming connection from " + sc.socket().getRemoteSocketAddress()); printRequest(sc); System.err.println("testing 1"); String HELLO_REPLY = "Sample Display"; ByteBuffer buffer = ByteBuffer.wrap(HELLO_REPLY.getBytes()); System.err.println("testing 2"); sc.write(buffer); System.err.println("testing 3"); sc.close(); }}} catch (IOException e) { e.printStackTrace(); } finally { if (ssc != null) { try { ssc.close(); } catch (IOException e) { e.printStackTrace(); } } } } catch(Exception E) { System.out.println("Ex in servCORE "+E); } } private static void printRequest(SocketChannel sc) throws IOException { ReadableByteChannel rbc = Channels.newChannel(sc.socket().getInputStream()); WritableByteChannel wbc = Channels.newChannel(System.out); ByteBuffer b = ByteBuffer.allocate(1024); // read 1024 bytes while (rbc.read(b) != -1) { b.flip(); while (b.hasRemaining()) { wbc.write(b); System.out.println(); } b.clear(); } } public void register_server(ServerSocketChannel ssc,int selectionkey_ops)throws Exception { ssc.register(sckt_manager,selectionkey_ops); }} public class HelloClient { public void coreClientChat() { Clientcore t=new Clientcore(); new Thread(t).start(); } public static void main(String[] args)throws Exception { HelloClient cl= new HelloClient(); cl.coreClientChat(); }} public class HelloServer { public void coreServerChat() { ServerCore t=new ServerCore(); new Thread(t).start(); } public static void main(String[] args) { HelloServer st= new HelloServer(); st.coreServerChat(); }}

    Read the article

  • cannot ssh to computer behind a dd-wrt bridge

    - by Jayaraman
    In my home network , i have dd-wrt router in another room , which bridges wifi from main home router (linksys) to the computers wired behind dd-wrt router. Now I cannot ssh from my laptop ( connected to linksys wifi) to the computers behind dd-wrt wifi bridge. I am able to ping the individual computers behind the dd-wrt bridge. When it comes to ssh or telnet to the computers , it is blocked. What can I do to make dd-wrt bridge to open up all ports in the dd-wrt bridge ?

    Read the article

  • Wifi Drops Connections with WPA2-PSK

    - by graf_ignotiev
    I run a small computer lab made up of 10 computers of identical hardware and software (Dell Latitudes with Windows 7 x64 Enterprise) and I use a ZyWALL 2WG as a router/firewall. Nine of the computers connect to the router over wifi using WPA2-PSK encryption while the last one is connected by ethernet cable. I'm having a problem where any computer connected to the wi-fi occasionally drops off the network (it cannot be pinged and the client cannot ping the gateway). It only happens on the wifi side and only when the encryption is WPA2-PSK or WPA-PSK. I tried using another router with a different make and model and had no problems. Thinking it could be a software error, I reset the router to factory defaults and installed the newest firmware (V4.04(AQI.8) | 04/09/2010), but still have the problem. The 802.1X log gives the following error User logout because of user disassociation. with this note WPA2-PSK:00242c582ece:logout where 00242c582ece is the mac address of the device. At this point I'm out of things to try and leads to follow. It looks like this user had the same or similar problem, but none of those proposed solutions work for me.

    Read the article

  • router - Problem Sharing internet connection in my router

    - by luis velasco
    Hi we are 4 roomates at the university but I have a problem. One of my roomies is downloading torrents all the time. When somebody need make a call or doing something like you tube or a quiz using the internet conection. The internet is very slow.... I can not create a network using a computer as a proxy. I just need a good router (and in the budget no more than $50).. I just want to split 16MB. In a separated 4 x 4 mb (theoretically)..

    Read the article

  • Cannot access SMC8014WG-SI provided by TimeWarner/RoadRunner administrative interface...

    - by Matt Rogish
    I just received installation of RoadRunner internet/TV/Voice and I was given a wi-fi router from the TimeWarner folks. The model is a SMC SMC8014WG-SI. Unfortunately, the password it uses is WEP and that is, as we all know, completely insecure. The tech that was here didn't know how to change it to something like WPA2 w/TKIP, and I was on hold for 20 minutes with the TimeWarner folks before I gave up. My problem is that the default web interface (http://192.168.0.1) isn't responding. I can ping it, I can access the internet through it, but I can't get to the admin interface. I did a "hard reset" of the device but still no dice. My suspicion is that the wi-fi admin interface is disabled (a common setting) but the wired interface isn't working on either of my two laptops (I've tried two laptops with two different cables, no link light activated). Am I SOL? Did they lock this down so I can't do what I want to do? Worst-case is I just hook up my go-to WRT54G router to the other modem and leave this one turned off, but I'd rather use their hardware to avoid any "It's not our problem" in the future. Any thoughts? Thanks!!

    Read the article

  • brctl Not working fine with bridging eth0 and at0

    - by Passi0n
    I made an access point with airbase-ng and its at0 I tried to bridge my eth0 and at0 by brctl addbr demo brctl addif demo eth0 brctl addif demo at0 brctl demo up dhclient3 demo & already removed eth0 ip so when i use ping 192.168.1.1 -I eth0 theres no reply but if i use ping 192.168.1.1 -I demo it works!!! In browser internet works fine so when i connect my android with at0 (access point) it should same work. but its now working at all :(

    Read the article

  • Stack-based keyboard delay using Logitech MX3100 keyboard

    - by Mark S. Rasmussen
    I've been using a Logitech Cordless Desktop MX3100 keyboard for quite a while. I've never really had any problems, except for the occasional typo. I noticed however that I tended make the typo "Laod" instead of "Load", quite a bit more often than any other typos. As it started to get on my nerves, I decided to do some testing. What I found out was than when I write lowercase "load", I'd never make the typo. All uppercase, or just uppercase L, I'd make the typo quite often. My actual (very scientific) testing is probably best described by showing the output: moatmoatmoat MoatMoatMoat loatloatloat LaotLaotLaot loafloafloaf LaofLaofLaof hoathoathoat HoatHoatHoat hoadhoadhoad HoadHoadHoad lortlortlort LrotLrotLrot What i found out was that whenever shift was depressed, typing an uppercase "L" would induce a significant lag if the next character was an "o", compared to the lag of the any other key: High "o" lag: LoLoLoLoLoLo No "a" lag: LaLaLaLaLaLa No lag for neither "o" nor "a": lolololololo lalalalalala By realizing this I regained a slight bit of sanity as I knew I wasn't coming down with a case of Parkinsons. I was actually typing correctly, the lag just interpreted it wrongly. Now, what really bugs me is that I can't fathom how this is occurring. What I'm actually typing, in physical order, is this: L - o - a - d, and yet, the "a" is output before the "o", even though "o" was pressed before "a". So while the keyboard is processing the "Lo" combo, the "a" gets prioritized and is inserted before the "o" is done processing, resulting in Laod instead of Load. And this only happens when typing "Lo", not when typing lowercase "lo". This problem could stem from the keyboard hardware, the receiver hardware or the keyboard software driver. No matter the fault location however, I can't imagine how this could be implemented as anything but a FIFO queue. A general delay, sure, I could live with that, albeit I'd be irritated. But a lag affecting different keys differently, and even resulting in unpredictable outcome - that just doesn't make any sense. I've solved the problem by just switching to a wired keyboard. I just can't shake it off me though; what kind of bug/error/scenario would result in a case like this? Edit: It's been suggested that I stop drinking Red Bull and stick to water instead. While that may actually help solve the issue, I'm really not looking for a solution as such. I'm more interested in an explanation of how this could happen, as I can't imagine any viable technical solution that could result in this behavior.

    Read the article

< Previous Page | 244 245 246 247 248 249 250 251 252 253 254 255  | Next Page >