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  • recent unreliable wireless connection on 10.04 and 10.10

    - by gabkdlly
    Recently, my internet connection over wireless has become unreliable, on both a Dell laptop running Ubuntu 10.04 as well as my Desktop running Ubuntu 10.10 . The problem does not seem to occur on a laptop running Windows Vista. The problem does not seem to occur on my Openmoko Freerunner ( running Android 1.5 ), though I hardly ever use this device to connect over WLAN, so the problem may have just slipped by. This problem does not seem to appear when I boot into Ubuntu 9.10 from a live CD ( more precisely, I was able to ping fu-berlin.de for an hour without any packet loss ). Under Ubuntu 10.10, I am experiencing about 33% packet loss. On my main Ubuntu Desktop, I have tried the following wireless devices: a Longshine PCI card ( an old device with an RTL8180L chip ) a D-Link DWL-510 PCI card ( this device threw warnings in dmesg ) a USB device from MSI ( US54EX ). Usually my wireless network shows up in the network manager with a normal signal strength, even when the connection speed is slow ( which happens often ) or the connection gets reset ( asking me to click connect to re-authenticate my wireless connection ). I have observed this problem with a Netgear KWGR614 Router ( with the manufacturers firmware ), as well as with a TP-LINK TL-WR741ND router running OpenWrt. Taking a look at my routers logs, I find many instances of the following line: Tuesday,04 Jan 2011 03:53:01 [TCP SYN Flood][Deny access policy matched, dropping packet] I know that the Netgear router is susceptible to denial of service attacks, as I have previously been able to disrupt its operation by putting an nmap scan into a while loop. I use WEP on the Netgear router and WPA on the TP-LINK to encrypt the wireless connections. Is it possible that someone is jamming my signal ?

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  • How do I make my multicast program work between computers on different networks?

    - by George
    I made a little chat applet using multicast. It works fine between computers on the same network, but fails if the computers are on different networks. Why is this? import java.io.*; import java.net.*; import java.awt.*; import java.awt.event.*; import javax.swing.*; public class ClientA extends JApplet implements ActionListener, Runnable { JTextField tf; JTextArea ta; MulticastSocket socket; InetAddress group; String name=""; public void start() { try { socket = new MulticastSocket(7777); group = InetAddress.getByName("233.0.0.1"); socket.joinGroup(group); socket.setTimeToLive(255); Thread th = new Thread(this); th.start(); name =JOptionPane.showInputDialog(null,"Please enter your name.","What is your name?",JOptionPane.PLAIN_MESSAGE); tf.grabFocus(); }catch(Exception e) {e.printStackTrace();} } public void init() { JPanel p = new JPanel(new BorderLayout()); ta = new JTextArea(); ta.setEditable(false); ta.setLineWrap(true); JScrollPane sp = new JScrollPane(ta); p.add(sp,BorderLayout.CENTER); JPanel p2 = new JPanel(); tf = new JTextField(30); tf.addActionListener(this); p2.add(tf); JButton b = new JButton("Send"); b.addActionListener(this); p2.add(b); p.add(p2,BorderLayout.SOUTH); add(p); } public void actionPerformed(ActionEvent ae) { String message = name+":"+tf.getText(); tf.setText(""); tf.grabFocus(); byte[] buf = message.getBytes(); DatagramPacket packet = new DatagramPacket(buf,buf.length, group,7777); try { socket.send(packet); } catch(Exception e) {} } public void run() { while(true) { byte[] buf = new byte[256]; String received = ""; DatagramPacket packet = new DatagramPacket(buf, buf.length); try { socket.receive(packet); received = new String(packet.getData()).trim(); } catch(Exception e) {} ta.append(received +"\n"); ta.setCaretPosition(ta.getDocument().getLength()); } } }

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  • Feedback on Optimizing C# NET Code Block

    - by Brett Powell
    I just spent quite a few hours reading up on TCP servers and my desired protocol I was trying to implement, and finally got everything working great. I noticed the code looks like absolute bollocks (is the the correct usage? Im not a brit) and would like some feedback on optimizing it, mostly for reuse and readability. The packet formats are always int, int, int, string, string. try { BinaryReader reader = new BinaryReader(clientStream); int packetsize = reader.ReadInt32(); int requestid = reader.ReadInt32(); int serverdata = reader.ReadInt32(); Console.WriteLine("Packet Size: {0} RequestID: {1} ServerData: {2}", packetsize, requestid, serverdata); List<byte> str = new List<byte>(); byte nextByte = reader.ReadByte(); while (nextByte != 0) { str.Add(nextByte); nextByte = reader.ReadByte(); } // Password Sent to be Authenticated string string1 = Encoding.UTF8.GetString(str.ToArray()); str.Clear(); nextByte = reader.ReadByte(); while (nextByte != 0) { str.Add(nextByte); nextByte = reader.ReadByte(); } // NULL string string string2 = Encoding.UTF8.GetString(str.ToArray()); Console.WriteLine("String1: {0} String2: {1}", string1, string2); // Reply to Authentication Request MemoryStream stream = new MemoryStream(); BinaryWriter writer = new BinaryWriter(stream); writer.Write((int)(1)); // Packet Size writer.Write((int)(requestid)); // Mirror RequestID if Authenticated, -1 if Failed byte[] buffer = stream.ToArray(); clientStream.Write(buffer, 0, buffer.Length); clientStream.Flush(); } I am going to be dealing with other packet types as well that are formatted the same (int/int/int/str/str), but different values. I could probably create a packet class, but this is a bit outside my scope of knowledge for how to apply it to this scenario. If it makes any difference, this is the Protocol I am implementing. http://developer.valvesoftware.com/wiki/Source_RCON_Protocol

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  • XNA Multiplayer Games and Networking

    - by JoshReuben
    ·        XNA communication must by default be lightweight – if you are syncing game state between players from the Game.Update method, you must minimize traffic. That game loop may be firing 60 times a second and player 5 needs to know if his tank has collided with any player 3 and the angle of that gun turret. There are no WCF ServiceContract / DataContract niceties here, but at the same time the XNA networking stack simplifies the details. The payload must be simplistic - just an ordered set of numbers that you would map to meaningful enum values upon deserialization.   Overview ·        XNA allows you to create and join multiplayer game sessions, to manage game state across clients, and to interact with the friends list ·        Dependency on Gamer Services - to receive notifications such as sign-in status changes and game invitations ·        two types of online multiplayer games: system link game sessions (LAN) and LIVE sessions (WAN). ·        Minimum dev requirements: 1 Xbox 360 console + Creators Club membership to test network code - run 1 instance of game on Xbox 360, and 1 on a Windows-based computer   Network Sessions ·        A network session is made up of players in a game + up to 8 arbitrary integer properties describing the session ·        create custom enums – (e.g. GameMode, SkillLevel) as keys in NetworkSessionProperties collection ·        Player state: lobby, in-play   Session Types ·        local session - for split-screen gaming - requires no network traffic. ·        system link session - connects multiple gaming machines over a local subnet. ·        Xbox LIVE multiplayer session - occurs on the Internet. Ranked or unranked   Session Updates ·        NetworkSession class Update method - must be called once per frame. ·        performs the following actions: o   Sends the network packets. o   Changes the session state. o   Raises the managed events for any significant state changes. o   Returns the incoming packet data. ·        synchronize the session à packet-received and state-change events à no threading issues   Session Config ·        Session host - gaming machine that creates the session. XNA handles host migration ·        NetworkSession properties: AllowJoinInProgress , AllowHostMigration ·        NetworkSession groups: AllGamers, LocalGamers, RemoteGamers   Subscribe to NetworkSession events ·        GamerJoined ·        GamerLeft ·        GameStarted ·        GameEnded – use to return to lobby ·        SessionEnded – use to return to title screen   Create a Session session = NetworkSession.Create(         NetworkSessionType.SystemLink,         maximumLocalPlayers,         maximumGamers,         privateGamerSlots,         sessionProperties );   Start a Session if (session.IsHost) {     if (session.IsEveryoneReady)     {        session.StartGame();        foreach (var gamer in SignedInGamer.SignedInGamers)        {             gamer.Presence.PresenceMode =                 GamerPresenceMode.InCombat;   Find a Network Session AvailableNetworkSessionCollection availableSessions = NetworkSession.Find(     NetworkSessionType.SystemLink,       maximumLocalPlayers,     networkSessionProperties); availableSessions.AllowJoinInProgress = true;   Join a Network Session NetworkSession session = NetworkSession.Join(     availableSessions[selectedSessionIndex]);   Sending Network Data var packetWriter = new PacketWriter(); foreach (LocalNetworkGamer gamer in session.LocalGamers) {     // Get the tank associated with this player.     Tank myTank = gamer.Tag as Tank;     // Write the data.     packetWriter.Write(myTank.Position);     packetWriter.Write(myTank.TankRotation);     packetWriter.Write(myTank.TurretRotation);     packetWriter.Write(myTank.IsFiring);     packetWriter.Write(myTank.Health);       // Send it to everyone.     gamer.SendData(packetWriter, SendDataOptions.None);     }   Receiving Network Data foreach (LocalNetworkGamer gamer in session.LocalGamers) {     // Keep reading while packets are available.     while (gamer.IsDataAvailable)     {         NetworkGamer sender;          // Read a single packet.         gamer.ReceiveData(packetReader, out sender);          if (!sender.IsLocal)         {             // Get the tank associated with this packet.             Tank remoteTank = sender.Tag as Tank;              // Read the data and apply it to the tank.             remoteTank.Position = packetReader.ReadVector2();             …   End a Session if (session.AllGamers.Count == 1)         {             session.EndGame();             session.Update();         }   Performance •        Aim to minimize payload, reliable in order messages •        Send Data Options: o   Unreliable, out of order -(SendDataOptions.None) o   Unreliable, in order (SendDataOptions.InOrder) o   Reliable, out of order (SendDataOptions.Reliable) o   Reliable, in order (SendDataOptions.ReliableInOrder) o   Chat data (SendDataOptions.Chat) •        Simulate: NetworkSession.SimulatedLatency , NetworkSession.SimulatedPacketLoss •        Voice support – NetworkGamer properties: HasVoice ,IsTalking , IsMutedByLocalUser

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  • Using WKA in Large Coherence Clusters (Disabling Multicast)

    - by jpurdy
    Disabling hardware multicast (by configuring well-known addresses aka WKA) will place significant stress on the network. For messages that must be sent to multiple servers, rather than having a server send a single packet to the switch and having the switch broadcast that packet to the rest of the cluster, the server must send a packet to each of the other servers. While hardware varies significantly, consider that a server with a single gigabit connection can send at most ~70,000 packets per second. To continue with some concrete numbers, in a cluster with 500 members, that means that each server can send at most 140 cluster-wide messages per second. And if there are 10 cluster members on each physical machine, that number shrinks to 14 cluster-wide messages per second (or with only mild hyperbole, roughly zero). It is also important to keep in mind that network I/O is not only expensive in terms of the network itself, but also the consumption of CPU required to send (or receive) a message (due to things like copying the packet bytes, processing a interrupt, etc). Fortunately, Coherence is designed to rely primarily on point-to-point messages, but there are some features that are inherently one-to-many: Announcing the arrival or departure of a member Updating partition assignment maps across the cluster Creating or destroying a NamedCache Invalidating a cache entry from a large number of client-side near caches Distributing a filter-based request across the full set of cache servers (e.g. queries, aggregators and entry processors) Invoking clear() on a NamedCache The first few of these are operations that are primarily routed through a single senior member, and also occur infrequently, so they usually are not a primary consideration. There are cases, however, where the load from introducing new members can be substantial (to the point of destabilizing the cluster). Consider the case where cluster in the first paragraph grows from 500 members to 1000 members (holding the number of physical machines constant). During this period, there will be 500 new member introductions, each of which may consist of several cluster-wide operations (for the cluster membership itself as well as the partitioned cache services, replicated cache services, invocation services, management services, etc). Note that all of these introductions will route through that one senior member, which is sharing its network bandwidth with several other members (which will be communicating to a lesser degree with other members throughout this process). While each service may have a distinct senior member, there's a good chance during initial startup that a single member will be the senior for all services (if those services start on the senior before the second member joins the cluster). It's obvious that this could cause CPU and/or network starvation. In the current release of Coherence (3.7.1.3 as of this writing), the pure unicast code path also has less sophisticated flow-control for cluster-wide messages (compared to the multicast-enabled code path), which may also result in significant heap consumption on the senior member's JVM (from the message backlog). This is almost never a problem in practice, but with sufficient CPU or network starvation, it could become critical. For the non-operational concerns (near caches, queries, etc), the application itself will determine how much load is placed on the cluster. Applications intended for deployment in a pure unicast environment should be careful to avoid excessive dependence on these features. Even in an environment with multicast support, these operations may scale poorly since even with a constant request rate, the underlying workload will increase at roughly the same rate as the underlying resources are added. Unless there is an infrastructural requirement to the contrary, multicast should be enabled. If it can't be enabled, care should be taken to ensure the added overhead doesn't lead to performance or stability issues. This is particularly crucial in large clusters.

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  • linux routing bug?

    - by Balázs Pozsár
    I have been struggling with this not easily reproducible issue since a while. I am using linux kernel v3.1.0, and sometimes routing to a few IP addresses does not work. What seems to happen is that instead of sending the packet to the gateway, the kernel treats the destination address as local, and tries to gets its MAC address via ARP. For example, now my current IP address is 172.16.1.104/24, the gateway is 172.16.1.254: # ifconfig eth0 eth0 Link encap:Ethernet HWaddr 00:1B:63:97:FC:DC inet addr:172.16.1.104 Bcast:172.16.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:230772 errors:0 dropped:0 overruns:0 frame:0 TX packets:171013 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:191879370 (182.9 Mb) TX bytes:47173253 (44.9 Mb) Interrupt:17 # route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 172.16.1.254 0.0.0.0 UG 0 0 0 eth0 172.16.1.0 0.0.0.0 255.255.255.0 U 1 0 0 eth0 I can ping a few addresses, but not 172.16.0.59: # ping -c1 172.16.1.254 PING 172.16.1.254 (172.16.1.254) 56(84) bytes of data. 64 bytes from 172.16.1.254: icmp_seq=1 ttl=64 time=0.383 ms --- 172.16.1.254 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.383/0.383/0.383/0.000 ms root@pozsybook:~# ping -c1 172.16.0.1 PING 172.16.0.1 (172.16.0.1) 56(84) bytes of data. 64 bytes from 172.16.0.1: icmp_seq=1 ttl=63 time=5.54 ms --- 172.16.0.1 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 5.545/5.545/5.545/0.000 ms root@pozsybook:~# ping -c1 172.16.0.2 PING 172.16.0.2 (172.16.0.2) 56(84) bytes of data. 64 bytes from 172.16.0.2: icmp_seq=1 ttl=62 time=7.92 ms --- 172.16.0.2 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 7.925/7.925/7.925/0.000 ms root@pozsybook:~# ping -c1 172.16.0.59 PING 172.16.0.59 (172.16.0.59) 56(84) bytes of data. From 172.16.1.104 icmp_seq=1 Destination Host Unreachable --- 172.16.0.59 ping statistics --- 1 packets transmitted, 0 received, +1 errors, 100% packet loss, time 0ms When trying to ping 172.16.0.59, I can see in tcpdump that an ARP req was sent: # tcpdump -n -i eth0|grep ARP tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes 15:25:16.671217 ARP, Request who-has 172.16.0.59 tell 172.16.1.104, length 28 and /proc/net/arp has an incomplete entry for 172.16.0.59: # grep 172.16.0.59 /proc/net/arp 172.16.0.59 0x1 0x0 00:00:00:00:00:00 * eth0 Please note, that 172.16.0.59 is accessible from this LAN from other computers. Does anyone have any idea of what's going on? Thanks. update: replies to the comments below: there are no interfaces besides eth0 and lo the ARP req cannot be seen on the other end, but that's how it should work. the main problem is that an ARP req should not even be sent at the first place the problem persist even if I add an explicit route with the command "route add -host 172.16.0.59 gw 172.16.1.254 dev eth0"

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  • Cablemodem (SBG6580) firewall denying some outbound traffic? Why? Not configured [migrated]

    - by lairdb
    I finally got around to turning the syslog on for my cablemodem (Motorola Surfboard SBG6580) and I'm seeing about the expected amount of inbound attackage being blocked... 2014-05-30 21:59:02 Local0.Alert 192.168.111.1 May 31 04:58:56 2014 SYSLOG[0]: [Host 192.168.111.1] UDP 12.230.209.198,4500 --> 66.27.xx.xx,61459 DENY:Firewall interface [IP Fragmented Packet] attack 2014-05-30 21:59:02 Local0.Alert 192.168.111.1 May 31 04:58:56 2014 SYSLOG[0]: [Host 192.168.111.1] TCP 17.172.232.109,5223 --> 66.27.xx.xx,53814 DENY:Firewall interface access request 2014-05-30 21:59:02 Local0.Alert 192.168.111.1 May 31 04:58:57 2014 SYSLOG[0]: [Host 192.168.111.1] UDP 12.230.209.198,443 --> 66.27.xx.xx,53385 DENY: Firewall interface [IP Fragmented Packet] attack 2014-05-30 21:59:02 Local0.Alert 192.168.111.1 May 31 04:58:57 2014 SYSLOG[0]: [Host 192.168.111.1] UDP 12.230.209.198,4500 --> 66.27.xx.xx,61459 DENY:Firewall interface [IP Fragmented Packet] attack 2014-05-30 21:59:10 Local0.Alert 192.168.111.1 May 31 04:59:04 2014 SYSLOG[0]: [Host 192.168.111.1] UDP 12.230.209.198,443 --> 66.27.xx.xx,59960 DENY: Firewall interface [IP Fragmented Packet] attack 2014-05-30 21:59:10 Local0.Alert 192.168.111.1 May 31 04:59:04 2014 SYSLOG[0]: [Host 192.168.111.1] UDP 12.230.209.198,4500 --> 66.27.xx.xx,61459 DENY:Firewall interface [IP Fragmented Packet] attack ...and that's great. (Sad, but great.) But I'm also seeing a HUGE amount of what appears to be denied outbound connectivity: 2014-05-30 16:30:10 Local0.Alert 192.168.111.1 May 30 23:30:04 2014 SYSLOG[0]: [Host 192.168.111.1] TCP 192.168.111.100,58969 --> 38.81.66.127,443 DENY: Inbound or outbound access request 2014-05-30 16:30:10 Local0.Alert 192.168.111.1 May 30 23:30:04 2014 SYSLOG[0]: [Host 192.168.111.1] TCP 192.168.111.100,58969 --> 38.81.66.127,443 DENY: Inbound or outbound access request 2014-05-30 16:30:10 Local0.Alert 192.168.111.1 May 30 23:30:04 2014 SYSLOG[0]: [Host 192.168.111.1] TCP 192.168.111.100,58965 --> 162.222.41.13,443 DENY: Inbound or outbound access request 2014-05-30 16:30:10 Local0.Alert 192.168.111.1 May 30 23:30:04 2014 SYSLOG[0]: [Host 192.168.111.1] TCP 192.168.111.100,58965 --> 162.222.41.13,443 DENY: Inbound or outbound access request 2014-05-30 16:30:10 Local0.Alert 192.168.111.1 May 30 23:30:04 2014 SYSLOG[0]: [Host 192.168.111.1] TCP 192.168.111.100,58964 --> 38.81.66.179,443 DENY: Inbound or outbound access request 2014-05-30 16:30:10 Local0.Alert 192.168.111.1 May 30 23:30:04 2014 SYSLOG[0]: [Host 192.168.111.1] TCP 192.168.111.100,58964 --> 38.81.66.179,443 DENY: Inbound or outbound access request ...and Spot checking suggests that it's all legitimate traffic (Opening connections to CrashPlan, etc.), I have no restrictions configured in the modem; I don't see why it should be blocking anything. Am I misreading the log entry, and it's not actually being denied? (Seems unlikely.) Is the ISP (TWC) pushing deny tables that are not exposed in the UI? (Tinfoil hat too tight.) I'm confused. (The good news, such as it is, is that AFAIK I'm not experiencing any actual issues... but maybe I am; tough to tell.) Thanks.

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  • Need help modifying C++ application to accept continuous piped input in Linux

    - by GreeenGuru
    The goal is to mine packet headers for URLs visited using tcpdump. So far, I can save a packet header to a file using: tcpdump "dst port 80 and tcp[13] & 0x08 = 8" -A -s 300 | tee -a ./Desktop/packets.txt And I've written a program to parse through the header and extract the URL when given the following command: cat ~/Desktop/packets.txt | ./packet-parser.exe But what I want to be able to do is pipe tcpdump directly into my program, which will then log the data: tcpdump "dst port 80 and tcp[13] & 0x08 = 8" -A -s 300 | ./packet-parser.exe Here is the script as it is. The question is: how do I need to change it to support continuous input from tcpdump? #include <boost/regex.hpp> #include <fstream> #include <cstdio> // Needed to define ios::app #include <string> #include <iostream> int main() { // Make sure to open the file in append mode std::ofstream file_out("/var/local/GreeenLogger/url.log", std::ios::app); if (not file_out) std::perror("/var/local/GreeenLogger/url.log"); else { std::string text; // Get multiple lines of input -- raw std::getline(std::cin, text, '\0'); const boost::regex pattern("GET (\\S+) HTTP.*?[\\r\\n]+Host: (\\S+)"); boost::smatch match_object; bool match = boost::regex_search(text, match_object, pattern); if(match) { std::string output; output = match_object[2] + match_object[1]; file_out << output << '\n'; std::cout << output << std::endl; } file_out.close(); } } Thank you ahead of time for the help!

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  • Converting a size_t into an integer (c++)

    - by JeanOTF
    Hello, I've been trying to make a for loop that will iterate based off of the length of a network packet. In the API there exists a variable (size_t) by event.packet-dataLength. I want to iterate from 0 to event.packet-dataLength - 7 increasing i by 10 each time it iterates but I am having a world of trouble. I looked for solutions but have been unable to find anything useful. I tried converting the size_t to an unsigned int and doing the arithmetic with that but unfortunately it didn't work. Basically all I want is this: for (int i = 0; i < event.packet->dataLength - 7; i+=10) { } Though every time I do something like this or attempt at my conversions the i < # part is a huge number. They gave a printf statement in a tutorial for the API which used "%u" to print the actual number however when I convert it to an unsigned int it is still incorrect. I'm not sure where to go from here. Any help would be greatly appreciated :)

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  • Understanding byte order and functions like CFSwapInt32HostToBig

    - by Typeoneerror
    I've got an enumeration in my game. A simple string message with an appended PacketType is being sent with the message (so it knows what to do with the message) over GameKit WIFI connection. I used Apple's GKRocket sample code as a starting point. The code itself is working fantastically; I just want to understand what the line with CFSwapInt32HostToBig is doing. What on earth does that do? and why does it need to do it? My guess is that it's making sure the PacketType value can be converted to an unsigned integer so it can send it reliably, but that doesn't sound all that correct to me. The documentation states "Converts a 32-bit integer from big-endian format to the host’s native byte order." but I don't understand what the means really. typedef enum { PacketTypeStart, // packet to notify games to start PacketTypeRequestSetup, // server wants client info PacketTypeSetup, // send client info to server PacketTypeSetupComplete, // round trip made for completion PacketTypeTurn, // packet to notify game that a turn is up PacketTypeRoll, // packet to send roll to players PacketTypeEnd // packet to end game } PacketType; // .... - (void)sendPacket:(NSData *)data ofType:(PacketType)type { NSLog(@"sendPacket:ofType(%d)", type); // create the data with enough space for a uint NSMutableData *newPacket = [NSMutableData dataWithCapacity:([data length]+sizeof(uint32_t))]; // Data is prefixed with the PacketType so the peer knows what to do with it. uint32_t swappedType = CFSwapInt32HostToBig((uint32_t)type); // add uint to data [newPacket appendBytes:&swappedType length:sizeof(uint32_t)]; // add the rest of the data [newPacket appendData:data]; // Send data checking for success or failure NSError *error; BOOL didSend = [_gkSession sendDataToAllPeers:newPacket withDataMode:GKSendDataReliable error:&error]; if (!didSend) { NSLog(@"error in sendDataToPeers: %@", [error localizedDescription]); } }

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  • recvfrom returns invalid argument when *from* is passed

    - by Aditya Sehgal
    I am currently writing a small UDP server program in linux. The UDP server will receive packets from two different peers and will perform different operations based on from which peer it received the packet. I am trying to determine the source from where I receive the packet. However, when select returns and recvfrom is called, it returns with an error of Invalid Argument. If I pass NULL as the second last arguments, recvfrom succeeds. I have tried declaring fromAddr as struct sockaddr_storage, struct sockaddr_in, struct sockaddr without any success. Is their something wrong with this code? Is this the correct way to determine the source of the packet? The code snippet follows. ` /*TODO : update for TCP. use recv */ if((pkInfo->rcvLen=recvfrom(psInfo->sockFd, pkInfo->buffer, MAX_PKTSZ, 0, /* (struct sockaddr*)&fromAddr,*/ NULL, &(addrLen) )) < 0) { perror("RecvFrom failed\n"); } else { /*Apply Filter */ #if 0 struct sockaddr_in* tmpAddr; tmpAddr = (struct sockaddr_in* )&fromAddr; printf("Received Msg From %s\n",inet_ntoa(tmpAddr->sin_addr)); #endif printf("Packet Received of len = %d\n",pkInfo->rcvLen); } `

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  • TCP/IP Implementation General Questions

    - by user2971023
    I've implemented the concepts shown here; http://wiki.unity3d.com/index.php/Simple_TCP/IP_Client_-_Server outside of unity and it works. (though i had to create the TCPIPServerApp from scratch as i could not find the base project anywhere). I have some general questions on how to use tcp/ip properly however. I've done some research on tcp/ip itself but I'm still a little confused. It seems like using the method above doesn't guarantee that I'll see the message (res). It just checks on every update to see if there is a different message in res. What if multiple messages are sent and the program lags or something, will i miss the earlier packet(s)? Should i instead do an array so it stores the last X messages? How do i know the data was received? Do I need to add a message id and build in my own ack into the data? Should i check to see if the port is in use before setting up a connection? Sorry for all the questions. This is all new to me but I enjoy this very much! ... Below already answered By Anton, Thanks It sounds like tcp uses its own packet numbering to ensure the packets end up in the right order on the other side. What if a packet is missed, are the subsequent packets thrown away? Or is this numbering and packet ordering, only for handling data that is broken out into multiple packets? TCP will automatically break the data into multiple packets if necessary right?

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  • recvfrom() return values in Stop-and-Wait UDP?

    - by mavErick
    I am trying to implement a Stop-and-Wait UDP client-server socket program in C. As known, there are basically three possible scenarios for Stop-and-Wait flow control. i.e., After transmitting a packet, the sender receives a correct ACK and thus starts transmitting the next packet; the sender receives an incorrect ACK and thus retransmits this packet; the sender receives no ACK within a TIMEOUT and thus retransmits this packet. My idea is to differentiate these three scenarios with the return value of recvfrom() on the sender side. For scenario 1&2: recvfrom() just returns the length of the received ACK. Since in my implementation the incorrect ACK is of the same length of the correct one, so I will have to go deeper and check the contents of the ACK. It's not a big deal. I know how to do. Problems come when I am trying to recognize scenario 3 where no ACK is received. What confuses me is that my recvfrom() is within a while loop, so the recvfrom() will be called constantly. What will it return when the receiver is not actually sending the sender ACK? Is it 0 or 1?

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  • C# .Net 3.5 Asynchronous Socket Server Performance Problem

    - by iBrAaAa
    I'm developing an Asynchronous Game Server using .Net Socket Asynchronous Model( BeginAccept/EndAccept...etc.) The problem I'm facing is described like that: When I have only one client connected, the server response time is very fast but once a second client connects, the server response time increases too much. I've measured the time from a client sends a message to the server until it gets the reply in both cases. I found that the average time in case of one client is about 17ms and in case of 2 clients about 280ms!!! What I really see is that: When 2 clients are connected and only one of them is moving(i.e. requesting service from the server) it is equivalently equal to the case when only one client is connected(i.e. fast response). However, when the 2 clients move at the same time(i.e. requests service from the server at the same time) their motion becomes very slow (as if the server replies each one of them in order i.e. not simultaneously). Basically, what I am doing is that: When a client requests a permission for motion from the server and the server grants him the request, the server then broadcasts the new position of the client to all the players. So if two clients are moving in the same time, the server is eventually trying to broadcast to both clients the new position of each of them at the same time. EX: Client1 asks to go to position (2,2) Client2 asks to go to position (5,5) Server sends to each of Client1 & Client2 the same two messages: message1: "Client1 at (2,2)" message2: "Client2 at (5,5)" I believe that the problem comes from the fact that Socket class is thread safe according MSDN documentation http://msdn.microsoft.com/en-us/library/system.net.sockets.socket.aspx. (NOT SURE THAT IT IS THE PROBLEM) Below is the code for the server: /// /// This class is responsible for handling packet receiving and sending /// public class NetworkManager { /// /// An integer to hold the server port number to be used for the connections. Its default value is 5000. /// private readonly int port = 5000; /// /// hashtable contain all the clients connected to the server. /// key: player Id /// value: socket /// private readonly Hashtable connectedClients = new Hashtable(); /// /// An event to hold the thread to wait for a new client /// private readonly ManualResetEvent resetEvent = new ManualResetEvent(false); /// /// keeps track of the number of the connected clients /// private int clientCount; /// /// The socket of the server at which the clients connect /// private readonly Socket mainSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); /// /// The socket exception that informs that a client is disconnected /// private const int ClientDisconnectedErrorCode = 10054; /// /// The only instance of this class. /// private static readonly NetworkManager networkManagerInstance = new NetworkManager(); /// /// A delegate for the new client connected event. /// /// the sender object /// the event args public delegate void NewClientConnected(Object sender, SystemEventArgs e); /// /// A delegate for the position update message reception. /// /// the sender object /// the event args public delegate void PositionUpdateMessageRecieved(Object sender, PositionUpdateEventArgs e); /// /// The event which fires when a client sends a position message /// public PositionUpdateMessageRecieved PositionUpdateMessageEvent { get; set; } /// /// keeps track of the number of the connected clients /// public int ClientCount { get { return clientCount; } } /// /// A getter for this class instance. /// /// only instance. public static NetworkManager NetworkManagerInstance { get { return networkManagerInstance; } } private NetworkManager() {} /// Starts the game server and holds this thread alive /// public void StartServer() { //Bind the mainSocket to the server IP address and port mainSocket.Bind(new IPEndPoint(IPAddress.Any, port)); //The server starts to listen on the binded socket with max connection queue //1024 mainSocket.Listen(1024); //Start accepting clients asynchronously mainSocket.BeginAccept(OnClientConnected, null); //Wait until there is a client wants to connect resetEvent.WaitOne(); } /// /// Receives connections of new clients and fire the NewClientConnected event /// private void OnClientConnected(IAsyncResult asyncResult) { Interlocked.Increment(ref clientCount); ClientInfo newClient = new ClientInfo { WorkerSocket = mainSocket.EndAccept(asyncResult), PlayerId = clientCount }; //Add the new client to the hashtable and increment the number of clients connectedClients.Add(newClient.PlayerId, newClient); //fire the new client event informing that a new client is connected to the server if (NewClientEvent != null) { NewClientEvent(this, System.EventArgs.Empty); } newClient.WorkerSocket.BeginReceive(newClient.Buffer, 0, BasePacket.GetMaxPacketSize(), SocketFlags.None, new AsyncCallback(WaitForData), newClient); //Start accepting clients asynchronously again mainSocket.BeginAccept(OnClientConnected, null); } /// Waits for the upcoming messages from different clients and fires the proper event according to the packet type. /// /// private void WaitForData(IAsyncResult asyncResult) { ClientInfo sendingClient = null; try { //Take the client information from the asynchronous result resulting from the BeginReceive sendingClient = asyncResult.AsyncState as ClientInfo; // If client is disconnected, then throw a socket exception // with the correct error code. if (!IsConnected(sendingClient.WorkerSocket)) { throw new SocketException(ClientDisconnectedErrorCode); } //End the pending receive request sendingClient.WorkerSocket.EndReceive(asyncResult); //Fire the appropriate event FireMessageTypeEvent(sendingClient.ConvertBytesToPacket() as BasePacket); // Begin receiving data from this client sendingClient.WorkerSocket.BeginReceive(sendingClient.Buffer, 0, BasePacket.GetMaxPacketSize(), SocketFlags.None, new AsyncCallback(WaitForData), sendingClient); } catch (SocketException e) { if (e.ErrorCode == ClientDisconnectedErrorCode) { // Close the socket. if (sendingClient.WorkerSocket != null) { sendingClient.WorkerSocket.Close(); sendingClient.WorkerSocket = null; } // Remove it from the hash table. connectedClients.Remove(sendingClient.PlayerId); if (ClientDisconnectedEvent != null) { ClientDisconnectedEvent(this, new ClientDisconnectedEventArgs(sendingClient.PlayerId)); } } } catch (Exception e) { // Begin receiving data from this client sendingClient.WorkerSocket.BeginReceive(sendingClient.Buffer, 0, BasePacket.GetMaxPacketSize(), SocketFlags.None, new AsyncCallback(WaitForData), sendingClient); } } /// /// Broadcasts the input message to all the connected clients /// /// public void BroadcastMessage(BasePacket message) { byte[] bytes = message.ConvertToBytes(); foreach (ClientInfo client in connectedClients.Values) { client.WorkerSocket.BeginSend(bytes, 0, bytes.Length, SocketFlags.None, SendAsync, client); } } /// /// Sends the input message to the client specified by his ID. /// /// /// The message to be sent. /// The id of the client to receive the message. public void SendToClient(BasePacket message, int id) { byte[] bytes = message.ConvertToBytes(); (connectedClients[id] as ClientInfo).WorkerSocket.BeginSend(bytes, 0, bytes.Length, SocketFlags.None, SendAsync, connectedClients[id]); } private void SendAsync(IAsyncResult asyncResult) { ClientInfo currentClient = (ClientInfo)asyncResult.AsyncState; currentClient.WorkerSocket.EndSend(asyncResult); } /// Fires the event depending on the type of received packet /// /// The received packet. void FireMessageTypeEvent(BasePacket packet) { switch (packet.MessageType) { case MessageType.PositionUpdateMessage: if (PositionUpdateMessageEvent != null) { PositionUpdateMessageEvent(this, new PositionUpdateEventArgs(packet as PositionUpdatePacket)); } break; } } } The events fired are handled in a different class, here are the event handling code for the PositionUpdateMessage (Other handlers are irrelevant): private readonly Hashtable onlinePlayers = new Hashtable(); /// /// Constructor that creates a new instance of the GameController class. /// private GameController() { //Start the server server = new Thread(networkManager.StartServer); server.Start(); //Create an event handler for the NewClientEvent of networkManager networkManager.PositionUpdateMessageEvent += OnPositionUpdateMessageReceived; } /// /// this event handler is called when a client asks for movement. /// private void OnPositionUpdateMessageReceived(object sender, PositionUpdateEventArgs e) { Point currentLocation = ((PlayerData)onlinePlayers[e.PositionUpdatePacket.PlayerId]).Position; Point locationRequested = e.PositionUpdatePacket.Position; ((PlayerData)onlinePlayers[e.PositionUpdatePacket.PlayerId]).Position = locationRequested; // Broadcast the new position networkManager.BroadcastMessage(new PositionUpdatePacket { Position = locationRequested, PlayerId = e.PositionUpdatePacket.PlayerId }); }

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  • Delphi hook to redirect to different ip

    - by Chris
    What is the best way to redirect ANY browser to a different ip for specific sites? For example if the user will type www.facebook.com in any browser he will be redirected to 127.0.0.1. Also the same should happen if he will type 66.220.146.11. What I have until now is this: using the winpkfilter I am able to intercept all the traffic on port 80, with type(in or out), source ip, destination ip and packet. My problem is to modify somehow the packet so the browser will be redirected. This is the code that i have right now: program Pass; {$APPTYPE CONSOLE} uses SysUtils, Windows, Winsock, winpkf, iphlp; var iIndex, counter : DWORD; hFilt : THANDLE; Adapts : TCP_AdapterList; AdapterMode : ADAPTER_MODE; Buffer, ParsedBuffer : INTERMEDIATE_BUFFER; ReadRequest : ETH_REQUEST; hEvent : THANDLE; hAdapter : THANDLE; pEtherHeader : TEtherHeaderPtr; pIPHeader : TIPHeaderPtr; pTcpHeader : TTCPHeaderPtr; pUdpHeader : TUDPHeaderPtr; SourceIP, DestIP : TInAddr; thePacket : PChar; f : TextFile; SourceIpString, DestinationIpString : string; SourceName, DestinationName : string; function IPAddrToName(IPAddr : string) : string; var SockAddrIn : TSockAddrIn; HostEnt : PHostEnt; WSAData : TWSAData; begin WSAStartup($101, WSAData); SockAddrIn.sin_addr.s_addr := inet_addr(PChar(IPAddr)); HostEnt := gethostbyaddr(@SockAddrIn.sin_addr.S_addr, 4, AF_INET); if HostEnt < nil then begin result := StrPas(Hostent^.h_name) end else begin result := ''; end; end; procedure ReleaseInterface(); begin // Restore default mode AdapterMode.dwFlags := 0; AdapterMode.hAdapterHandle := hAdapter; SetAdapterMode(hFilt, @AdapterMode); // Set NULL event to release previously set event object SetPacketEvent(hFilt, hAdapter, 0); // Close Event if hEvent < 0 then CloseHandle(hEvent); // Close driver object CloseFilterDriver(hFilt); // Release NDISAPI FreeNDISAPI(); end; begin // Check the number of parameters if ParamCount() < 2 then begin Writeln('Command line syntax:'); Writeln(' PassThru.exe index num'); Writeln(' index - network interface index.'); Writeln(' num - number or packets to filter'); Writeln('You can use ListAdapters to determine correct index.'); Exit; end; // Initialize NDISAPI InitNDISAPI(); // Create driver object hFilt := OpenFilterDriver('NDISRD'); if IsDriverLoaded(hFilt) then begin // Get parameters from command line iIndex := StrToInt(ParamStr(1)); counter := StrToInt(ParamStr(2)); // Set exit procedure ExitProcessProc := ReleaseInterface; // Get TCP/IP bound interfaces GetTcpipBoundAdaptersInfo(hFilt, @Adapts); // Check paramer values if iIndex > Adapts.m_nAdapterCount then begin Writeln('There is no network interface with such index on this system.'); Exit; end; hAdapter := Adapts.m_nAdapterHandle[iIndex]; AdapterMode.dwFlags := MSTCP_FLAG_SENT_TUNNEL or MSTCP_FLAG_RECV_TUNNEL; AdapterMode.hAdapterHandle := hAdapter; // Create notification event hEvent := CreateEvent(nil, TRUE, FALSE, nil); if hEvent <> 0 then if SetPacketEvent(hFilt, hAdapter, hEvent) <> 0 then begin // Initialize request ReadRequest.EthPacket.Buffer := @Buffer; ReadRequest.hAdapterHandle := hAdapter; SetAdapterMode(hFilt, @AdapterMode); counter := 0; //while counter <> 0 do while true do begin WaitForSingleObject(hEvent, INFINITE); while ReadPacket(hFilt, @ReadRequest) <> 0 do begin //dec(counter); pEtherHeader := TEtherHeaderPtr(@Buffer.m_IBuffer); if ntohs(pEtherHeader.h_proto) = ETH_P_IP then begin pIPHeader := TIPHeaderPtr(Integer(pEtherHeader) + SizeOf(TEtherHeader)); SourceIP.S_addr := pIPHeader.SourceIp; DestIP.S_addr := pIPHeader.DestIp; if pIPHeader.Protocol = IPPROTO_TCP then begin pTcpHeader := TTCPHeaderPtr(Integer(pIPHeader) + (pIPHeader.VerLen and $F) * 4); if (pTcpHeader.SourcePort = htons(80)) or (pTcpHeader.DestPort = htons(80)) then begin inc(counter); if Buffer.m_dwDeviceFlags = PACKET_FLAG_ON_SEND then Writeln(counter, ') - MSTCP --> Interface') else Writeln(counter, ') - Interface --> MSTCP'); Writeln(' Packet size = ', Buffer.m_Length); Writeln(Format(' IP %.3u.%.3u.%.3u.%.3u --> %.3u.%.3u.%.3u.%.3u PROTOCOL: %u', [byte(SourceIP.S_un_b.s_b1), byte(SourceIP.S_un_b.s_b2), byte(SourceIP.S_un_b.s_b3), byte(SourceIP.S_un_b.s_b4), byte(DestIP.S_un_b.s_b1), byte(DestIP.S_un_b.s_b2), byte(DestIP.S_un_b.s_b3), byte(DestIP.S_un_b.s_b4), byte(pIPHeader.Protocol)] )); Writeln(Format(' TCP SRC PORT: %d DST PORT: %d', [ntohs(pTcpHeader.SourcePort), ntohs(pTcpHeader.DestPort)])); //get the data thePacket := pchar(pEtherHeader) + (sizeof(TEtherHeaderPtr) + pIpHeader.VerLen * 4 + pTcpHeader.Offset * 4); { SourceIpString := IntToStr(byte(SourceIP.S_un_b.s_b1)) + '.' + IntToStr(byte(SourceIP.S_un_b.s_b2)) + '.' + IntToStr(byte(SourceIP.S_un_b.s_b3)) + '.' + IntToStr(byte(SourceIP.S_un_b.s_b4)); DestinationIpString := IntToStr(byte(DestIP.S_un_b.s_b1)) + '.' + IntToStr(byte(DestIP.S_un_b.s_b2)) + '.' + IntToStr(byte(DestIP.S_un_b.s_b3)) + '.' + IntToStr(byte(DestIP.S_un_b.s_b4)); } end; end; end; // if ntohs(pEtherHeader.h_proto) = ETH_P_RARP then // Writeln(' Reverse Addr Res packet'); // if ntohs(pEtherHeader.h_proto) = ETH_P_ARP then // Writeln(' Address Resolution packet'); //Writeln('__'); if Buffer.m_dwDeviceFlags = PACKET_FLAG_ON_SEND then // Place packet on the network interface SendPacketToAdapter(hFilt, @ReadRequest) else // Indicate packet to MSTCP SendPacketToMstcp(hFilt, @ReadRequest); { if counter = 0 then begin Writeln('Filtering complete'); readln; break; end; } end; ResetEvent(hEvent); end; end; end; end.

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  • .Net 3.5 Asynchronous Socket Server Performance Problem

    - by iBrAaAa
    I'm developing an Asynchronous Game Server using .Net Socket Asynchronous Model( BeginAccept/EndAccept...etc.) The problem I'm facing is described like that: When I have only one client connected, the server response time is very fast but once a second client connects, the server response time increases too much. I've measured the time from a client sends a message to the server until it gets the reply in both cases. I found that the average time in case of one client is about 17ms and in case of 2 clients about 280ms!!! What I really see is that: When 2 clients are connected and only one of them is moving(i.e. requesting service from the server) it is equivalently equal to the case when only one client is connected(i.e. fast response). However, when the 2 clients move at the same time(i.e. requests service from the server at the same time) their motion becomes very slow (as if the server replies each one of them in order i.e. not simultaneously). Basically, what I am doing is that: When a client requests a permission for motion from the server and the server grants him the request, the server then broadcasts the new position of the client to all the players. So if two clients are moving in the same time, the server is eventually trying to broadcast to both clients the new position of each of them at the same time. EX: Client1 asks to go to position (2,2) Client2 asks to go to position (5,5) Server sends to each of Client1 & Client2 the same two messages: message1: "Client1 at (2,2)" message2: "Client2 at (5,5)" I believe that the problem comes from the fact that Socket class is thread safe according MSDN documentation http://msdn.microsoft.com/en-us/library/system.net.sockets.socket.aspx. (NOT SURE THAT IT IS THE PROBLEM) Below is the code for the server: /// /// This class is responsible for handling packet receiving and sending /// public class NetworkManager { /// /// An integer to hold the server port number to be used for the connections. Its default value is 5000. /// private readonly int port = 5000; /// /// hashtable contain all the clients connected to the server. /// key: player Id /// value: socket /// private readonly Hashtable connectedClients = new Hashtable(); /// /// An event to hold the thread to wait for a new client /// private readonly ManualResetEvent resetEvent = new ManualResetEvent(false); /// /// keeps track of the number of the connected clients /// private int clientCount; /// /// The socket of the server at which the clients connect /// private readonly Socket mainSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); /// /// The socket exception that informs that a client is disconnected /// private const int ClientDisconnectedErrorCode = 10054; /// /// The only instance of this class. /// private static readonly NetworkManager networkManagerInstance = new NetworkManager(); /// /// A delegate for the new client connected event. /// /// the sender object /// the event args public delegate void NewClientConnected(Object sender, SystemEventArgs e); /// /// A delegate for the position update message reception. /// /// the sender object /// the event args public delegate void PositionUpdateMessageRecieved(Object sender, PositionUpdateEventArgs e); /// /// The event which fires when a client sends a position message /// public PositionUpdateMessageRecieved PositionUpdateMessageEvent { get; set; } /// /// keeps track of the number of the connected clients /// public int ClientCount { get { return clientCount; } } /// /// A getter for this class instance. /// /// only instance. public static NetworkManager NetworkManagerInstance { get { return networkManagerInstance; } } private NetworkManager() {} /// Starts the game server and holds this thread alive /// public void StartServer() { //Bind the mainSocket to the server IP address and port mainSocket.Bind(new IPEndPoint(IPAddress.Any, port)); //The server starts to listen on the binded socket with max connection queue //1024 mainSocket.Listen(1024); //Start accepting clients asynchronously mainSocket.BeginAccept(OnClientConnected, null); //Wait until there is a client wants to connect resetEvent.WaitOne(); } /// /// Receives connections of new clients and fire the NewClientConnected event /// private void OnClientConnected(IAsyncResult asyncResult) { Interlocked.Increment(ref clientCount); ClientInfo newClient = new ClientInfo { WorkerSocket = mainSocket.EndAccept(asyncResult), PlayerId = clientCount }; //Add the new client to the hashtable and increment the number of clients connectedClients.Add(newClient.PlayerId, newClient); //fire the new client event informing that a new client is connected to the server if (NewClientEvent != null) { NewClientEvent(this, System.EventArgs.Empty); } newClient.WorkerSocket.BeginReceive(newClient.Buffer, 0, BasePacket.GetMaxPacketSize(), SocketFlags.None, new AsyncCallback(WaitForData), newClient); //Start accepting clients asynchronously again mainSocket.BeginAccept(OnClientConnected, null); } /// Waits for the upcoming messages from different clients and fires the proper event according to the packet type. /// /// private void WaitForData(IAsyncResult asyncResult) { ClientInfo sendingClient = null; try { //Take the client information from the asynchronous result resulting from the BeginReceive sendingClient = asyncResult.AsyncState as ClientInfo; // If client is disconnected, then throw a socket exception // with the correct error code. if (!IsConnected(sendingClient.WorkerSocket)) { throw new SocketException(ClientDisconnectedErrorCode); } //End the pending receive request sendingClient.WorkerSocket.EndReceive(asyncResult); //Fire the appropriate event FireMessageTypeEvent(sendingClient.ConvertBytesToPacket() as BasePacket); // Begin receiving data from this client sendingClient.WorkerSocket.BeginReceive(sendingClient.Buffer, 0, BasePacket.GetMaxPacketSize(), SocketFlags.None, new AsyncCallback(WaitForData), sendingClient); } catch (SocketException e) { if (e.ErrorCode == ClientDisconnectedErrorCode) { // Close the socket. if (sendingClient.WorkerSocket != null) { sendingClient.WorkerSocket.Close(); sendingClient.WorkerSocket = null; } // Remove it from the hash table. connectedClients.Remove(sendingClient.PlayerId); if (ClientDisconnectedEvent != null) { ClientDisconnectedEvent(this, new ClientDisconnectedEventArgs(sendingClient.PlayerId)); } } } catch (Exception e) { // Begin receiving data from this client sendingClient.WorkerSocket.BeginReceive(sendingClient.Buffer, 0, BasePacket.GetMaxPacketSize(), SocketFlags.None, new AsyncCallback(WaitForData), sendingClient); } } /// /// Broadcasts the input message to all the connected clients /// /// public void BroadcastMessage(BasePacket message) { byte[] bytes = message.ConvertToBytes(); foreach (ClientInfo client in connectedClients.Values) { client.WorkerSocket.BeginSend(bytes, 0, bytes.Length, SocketFlags.None, SendAsync, client); } } /// /// Sends the input message to the client specified by his ID. /// /// /// The message to be sent. /// The id of the client to receive the message. public void SendToClient(BasePacket message, int id) { byte[] bytes = message.ConvertToBytes(); (connectedClients[id] as ClientInfo).WorkerSocket.BeginSend(bytes, 0, bytes.Length, SocketFlags.None, SendAsync, connectedClients[id]); } private void SendAsync(IAsyncResult asyncResult) { ClientInfo currentClient = (ClientInfo)asyncResult.AsyncState; currentClient.WorkerSocket.EndSend(asyncResult); } /// Fires the event depending on the type of received packet /// /// The received packet. void FireMessageTypeEvent(BasePacket packet) { switch (packet.MessageType) { case MessageType.PositionUpdateMessage: if (PositionUpdateMessageEvent != null) { PositionUpdateMessageEvent(this, new PositionUpdateEventArgs(packet as PositionUpdatePacket)); } break; } } } The events fired are handled in a different class, here are the event handling code for the PositionUpdateMessage (Other handlers are irrelevant): private readonly Hashtable onlinePlayers = new Hashtable(); /// /// Constructor that creates a new instance of the GameController class. /// private GameController() { //Start the server server = new Thread(networkManager.StartServer); server.Start(); //Create an event handler for the NewClientEvent of networkManager networkManager.PositionUpdateMessageEvent += OnPositionUpdateMessageReceived; } /// /// this event handler is called when a client asks for movement. /// private void OnPositionUpdateMessageReceived(object sender, PositionUpdateEventArgs e) { Point currentLocation = ((PlayerData)onlinePlayers[e.PositionUpdatePacket.PlayerId]).Position; Point locationRequested = e.PositionUpdatePacket.Position; ((PlayerData)onlinePlayers[e.PositionUpdatePacket.PlayerId]).Position = locationRequested; // Broadcast the new position networkManager.BroadcastMessage(new PositionUpdatePacket { Position = locationRequested, PlayerId = e.PositionUpdatePacket.PlayerId }); }

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  • Wireless Connected But No Internet Connection (Ubuntu 12.04)

    - by Zxy
    I am using same network for 2 days and everything was normal. However, today even though it shows me as connected to the network, I do not have internet connection. If I use ethernet cable instead of wireless, I am still able to connect to the internet. Also my friends are able to connect to the wireless network and they can get internet connection. I did not update or install anything since yesterday. Therefore I do not have any idea why it is happening. Here is some information about my connection: I will be appreciate to any kind of help. root@ghostrider:/etc/resolvconf# ping 127.0.0.1 PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data. 64 bytes from 127.0.0.1: icmp_req=1 ttl=64 time=0.042 ms 64 bytes from 127.0.0.1: icmp_req=2 ttl=64 time=0.023 ms 64 bytes from 127.0.0.1: icmp_req=3 ttl=64 time=0.036 ms 64 bytes from 127.0.0.1: icmp_req=4 ttl=64 time=0.040 ms ^C --- 127.0.0.1 ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 2998ms rtt min/avg/max/mdev = 0.023/0.035/0.042/0.008 ms root@ghostrider:/etc/resolvconf# ping 192.168.1.3 PING 192.168.1.3 (192.168.1.3) 56(84) bytes of data. ^C --- 192.168.1.3 ping statistics --- 19 packets transmitted, 0 received, 100% packet loss, time 18143ms root@ghostrider:/etc/resolvconf# ping 8.8.8.8 PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data. ^C --- 8.8.8.8 ping statistics --- 11 packets transmitted, 0 received, 100% packet loss, time 10079ms root@ghostrider:/etc/resolvconf# cat /etc/lsb-release; uname -a DISTRIB_ID=Ubuntu DISTRIB_RELEASE=12.04 DISTRIB_CODENAME=precise DISTRIB_DESCRIPTION="Ubuntu 12.04 LTS" Linux ghostrider 3.2.0-24-generic-pae #39-Ubuntu SMP Mon May 21 18:54:21 UTC 2012 i686 i686 i386 GNU/Linux root@ghostrider:/etc/resolvconf# lspci -nnk | grep -iA2 net 03:00.0 Ethernet controller [0200]: Atheros Communications Inc. AR8131 Gigabit Ethernet [1969:1063] (rev c0) Subsystem: Lenovo Device [17aa:3956] Kernel driver in use: atl1c -- 04:00.0 Network controller [0280]: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller [14e4:4727] (rev 01) Subsystem: Broadcom Corporation Device [14e4:0510] Kernel driver in use: wl root@ghostrider:/etc/resolvconf# lsusb Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 007: ID 0489:e00d Foxconn / Hon Hai Bus 001 Device 004: ID 1c7a:0801 LighTuning Technology Inc. Fingerprint Reader Bus 001 Device 005: ID 064e:f219 Suyin Corp. Bus 002 Device 010: ID 0424:2412 Standard Microsystems Corp. Bus 002 Device 004: ID 046d:c52b Logitech, Inc. Unifying Receiver Bus 002 Device 011: ID 0403:6010 Future Technology Devices International, Ltd FT2232C Dual USB-UART/FIFO IC root@ghostrider:/etc/resolvconf# iwconfig lo no wireless extensions. eth1 IEEE 802.11 ESSID:"PoliTekno" Mode:Managed Frequency:2.462 GHz Access Point: 00:16:E3:40:C3:E4 Bit Rate=54 Mb/s Tx-Power:24 dBm Retry min limit:7 RTS thr:off Fragment thr:off Power Management:off Link Quality=5/5 Signal level=-52 dBm Noise level=-97 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0 eth0 no wireless extensions. root@ghostrider:/etc/resolvconf# rfkill list all 0: brcmwl-0: Wireless LAN Soft blocked: no Hard blocked: no 1: ideapad_wlan: Wireless LAN Soft blocked: no Hard blocked: no 2: ideapad_bluetooth: Bluetooth Soft blocked: no Hard blocked: no 5: hci0: Bluetooth Soft blocked: no Hard blocked: no root@ghostrider:/etc/resolvconf# lsmod Module Size Used by nls_iso8859_1 12617 0 nls_cp437 12751 0 vfat 17308 0 fat 55605 1 vfat usb_storage 39646 0 uas 17828 0 snd_hda_codec_realtek 174055 1 rfcomm 38139 12 parport_pc 32114 0 ppdev 12849 0 bnep 17830 2 joydev 17393 0 ftdi_sio 35859 1 usbserial 37173 3 ftdi_sio snd_hda_intel 32765 3 snd_hda_codec 109562 2 snd_hda_codec_realtek,snd_hda_intel snd_hwdep 13276 1 snd_hda_codec acer_wmi 23612 0 hid_logitech_dj 18177 0 snd_pcm 80845 2 snd_hda_intel,snd_hda_codec uvcvideo 67203 0 btusb 17912 2 snd_seq_midi 13132 0 videodev 86588 1 uvcvideo bluetooth 158438 23 rfcomm,bnep,btusb psmouse 72919 0 usbhid 41906 1 hid_logitech_dj snd_rawmidi 25424 1 snd_seq_midi intel_ips 17753 0 serio_raw 13027 0 root@ghostrider:/etc/resolvconf# ping 127.0.0.1 PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data. 64 bytes from 127.0.0.1: icmp_req=1 ttl=64 time=0.042 ms 64 bytes from 127.0.0.1: icmp_req=2 ttl=64 time=0.023 ms 64 bytes from 127.0.0.1: icmp_req=3 ttl=64 time=0.036 ms 64 bytes from 127.0.0.1: icmp_req=4 ttl=64 time=0.040 ms ^C --- 127.0.0.1 ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 2998ms rtt min/avg/max/mdev = 0.023/0.035/0.042/0.008 ms root@ghostrider:/etc/resolvconf# ping 192.168.1.3 PING 192.168.1.3 (192.168.1.3) 56(84) bytes of data. ^C --- 192.168.1.3 ping statistics --- 19 packets transmitted, 0 received, 100% packet loss, time 18143ms root@ghostrider:/etc/resolvconf# ping 8.8.8.8 PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data. ^C --- 8.8.8.8 ping statistics --- 11 packets transmitted, 0 received, 100% packet loss, time 10079ms root@ghostrider:/etc/resolvconf# cat /etc/lsb-release; uname -a DISTRIB_ID=Ubuntu DISTRIB_RELEASE=12.04 DISTRIB_CODENAME=precise DISTRIB_DESCRIPTION="Ubuntu 12.04 LTS" Linux ghostrider 3.2.0-24-generic-pae #39-Ubuntu SMP Mon May 21 18:54:21 UTC 2012 i686 i686 i386 GNU/Linux root@ghostrider:/etc/resolvconf# lspci -nnk | grep -iA2 net 03:00.0 Ethernet controller [0200]: Atheros Communications Inc. AR8131 Gigabit Ethernet [1969:1063] (rev c0) Subsystem: Lenovo Device [17aa:3956] Kernel driver in use: atl1c -- 04:00.0 Network controller [0280]: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller [14e4:4727] (rev 01) Subsystem: Broadcom Corporation Device [14e4:0510] Kernel driver in use: wl root@ghostrider:/etc/resolvconf# lsusb Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 007: ID 0489:e00d Foxconn / Hon Hai Bus 001 Device 004: ID 1c7a:0801 LighTuning Technology Inc. Fingerprint Reader Bus 001 Device 005: ID 064e:f219 Suyin Corp. Bus 002 Device 010: ID 0424:2412 Standard Microsystems Corp. Bus 002 Device 004: ID 046d:c52b Logitech, Inc. Unifying Receiver Bus 002 Device 011: ID 0403:6010 Future Technology Devices International, Ltd FT2232C Dual USB-UART/FIFO IC root@ghostrider:/etc/resolvconf# iwconfig lo no wireless extensions. eth1 IEEE 802.11 ESSID:"PoliTekno" Mode:Managed Frequency:2.462 GHz Access Point: 00:16:E3:40:C3:E4 Bit Rate=54 Mb/s Tx-Power:24 dBm Retry min limit:7 RTS thr:off Fragment thr:off Power Management:off Link Quality=5/5 Signal level=-52 dBm Noise level=-97 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0 eth0 no wireless extensions. root@ghostrider:/etc/resolvconf# rfkill list all 0: brcmwl-0: Wireless LAN Soft blocked: no Hard blocked: no 1: ideapad_wlan: Wireless LAN Soft blocked: no Hard blocked: no 2: ideapad_bluetooth: Bluetooth Soft blocked: no Hard blocked: no 5: hci0: Bluetooth Soft blocked: no Hard blocked: no root@ghostrider:/etc/resolvconf# lsmod Module Size Used by nls_iso8859_1 12617 0 nls_cp437 12751 0 vfat 17308 0 fat 55605 1 vfat usb_storage 39646 0 uas 17828 0 snd_hda_codec_realtek 174055 1 rfcomm 38139 12 parport_pc 32114 0 ppdev 12849 0 bnep 17830 2 joydev 17393 0 ftdi_sio 35859 1 usbserial 37173 3 ftdi_sio snd_hda_intel 32765 3 snd_hda_codec 109562 2 snd_hda_codec_realtek,snd_hda_intel snd_hwdep 13276 1 snd_hda_codec acer_wmi 23612 0 hid_logitech_dj 18177 0 snd_pcm 80845 2 snd_hda_intel,snd_hda_codec uvcvideo 67203 0 btusb 17912 2 snd_seq_midi 13132 0 videodev 86588 1 uvcvideo bluetooth 158438 23 rfcomm,bnep,btusb psmouse 72919 0 usbhid 41906 1 hid_logitech_dj snd_rawmidi 25424 1 snd_seq_midi intel_ips 17753 0 serio_raw 13027 0 hid 77367 2 hid_logitech_dj,usbhid ideapad_laptop 17890 0 sparse_keymap 13658 2 acer_wmi,ideapad_laptop lib80211_crypt_tkip 17275 0 snd_seq_midi_event 14475 1 snd_seq_midi snd_seq 51567 2 snd_seq_midi,snd_seq_midi_event wl 2646601 0 wmi 18744 1 acer_wmi i915 414672 3 drm_kms_helper 45466 1 i915 snd_timer 28931 2 snd_pcm,snd_seq mac_hid 13077 0 snd_seq_device 14172 3 snd_seq_midi,snd_rawmidi,snd_seq lib80211 14040 2 lib80211_crypt_tkip,wl drm 197692 4 i915,drm_kms_helper i2c_algo_bit 13199 1 i915 snd 62064 15 snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm,snd_rawmidi,snd_se q,snd_timer,snd_seq_device video 19068 1 i915 mei 36570 0 soundcore 14635 1 snd snd_page_alloc 14108 2 snd_hda_intel,snd_pcm lp 17455 0 parport 40930 3 parport_pc,ppdev,lp atl1c 36718 0 root@ghostrider:/etc/resolvconf# nm-tool NetworkManager Tool State: connected (global) - Device: eth1 [PoliTekno] ---------------------------------------------------- Type: 802.11 WiFi Driver: wl State: connected Default: yes HW Address: AC:81:12:7F:6B:B2 Capabilities: Speed: 54 Mb/s Wireless Properties WEP Encryption: yes WPA Encryption: yes WPA2 Encryption: yes Wireless Access Points (* = current AP) CnDStudios: Infra, 00:12:BF:3F:0A:8A, Freq 2412 MHz, Rate 54 Mb/s, Strength 85 WPA AIR_TIES: Infra, 00:1C:A8:6E:84:32, Freq 2462 MHz, Rate 54 Mb/s, Strength 72 WPA2 VKSS: Infra, 00:E0:4D:01:0D:47, Freq 2452 MHz, Rate 54 Mb/s, Strength 62 WPA2 PROGEDA: Infra, 00:1A:2A:60:BF:61, Freq 2462 MHz, Rate 54 Mb/s, Strength 47 WPA MobilAtolye: Infra, 72:2B:C1:65:75:3C, Freq 2422 MHz, Rate 54 Mb/s, Strength 35 WPA WPA2 AIRTIES_WAR-141: Infra, 00:1C:A8:AB:AA:48, Freq 2422 MHz, Rate 54 Mb/s, Strength 35 WPA WPA2 tilda_biri_yeni: Infra, 54:E6:FC:B0:3C:E9, Freq 2437 MHz, Rate 0 Mb/s, Strength 34 WEP *PoliTekno: Infra, 00:16:E3:40:C3:E4, Freq 2462 MHz, Rate 54 Mb/s, Strength 100 WPA2 AIRTIES_RJY: Infra, 00:1A:2A:BD:85:16, Freq 2462 MHz, Rate 54 Mb/s, Strength 55 WEP IPv4 Settings: Address: 0.0.0.0 Prefix: 24 (255.255.255.0) Gateway: 192.168.1.1 DNS: 192.168.1.1 - Device: eth0 ----------------------------------------------------------------- Type: Wired Driver: atl1c State: unavailable Default: no HW Address: F0:DE:F1:6C:90:65 Capabilities: Carrier Detect: yes Speed: 100 Mb/s Wired Properties Carrier: off root@ghostrider:/etc/resolvconf# sudo iwlist scan lo Interface doesn't support scanning. eth1 Scan completed : Cell 01 - Address: 00:16:E3:40:C3:E4 ESSID:"PoliTekno" Mode:Managed Frequency:2.462 GHz (Channel 11) Quality:5/5 Signal level:-48 dBm Noise level:-98 dBm IE: IEEE 802.11i/WPA2 Version 1 Group Cipher : CCMP Pairwise Ciphers (1) : CCMP Authentication Suites (1) : PSK Encryption key:on Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s 24 Mb/s; 36 Mb/s; 54 Mb/s; 6 Mb/s; 9 Mb/s 12 Mb/s; 48 Mb/s Cell 02 - Address: 00:E0:4D:01:0D:47 ESSID:"VKSS" Mode:Managed Frequency:2.452 GHz (Channel 9) Quality:4/5 Signal level:-64 dBm Noise level:-98 dBm IE: IEEE 802.11i/WPA2 Version 1 Group Cipher : CCMP Pairwise Ciphers (1) : CCMP Authentication Suites (1) : PSK Encryption key:on Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s 48 Mb/s; 54 Mb/s Cell 03 - Address: 00:1C:A8:AB:AA:48 ESSID:"AIRTIES_WAR-141" Mode:Managed Frequency:2.422 GHz (Channel 3) Quality:2/5 Signal level:-77 dBm Noise level:-95 dBm IE: IEEE 802.11i/WPA2 Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : CCMP TKIP Authentication Suites (1) : PSK IE: Unknown: DDB20050F204104A0001101049001E007FC5100018DE7CF0D8B70223A62711C18926AC290E30303030303139631044000102103B0001031047001076B31BC241E953CB99C3872554425A28102100194169725469657320576972656C657373204E6574776F726B73102300074169723534343010240008312E322E302E31321042000F4154303939313131383030323832351054000800060050F20400011011000741697235343430100800020084103C000103 IE: WPA Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : CCMP TKIP Authentication Suites (1) : PSK Encryption key:on Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s 24 Mb/s; 36 Mb/s; 54 Mb/s; 6 Mb/s; 9 Mb/s 12 Mb/s; 48 Mb/s Cell 04 - Address: 72:2B:C1:65:75:3C ESSID:"MobilAtolye" Mode:Managed Frequency:2.422 GHz (Channel 3) Quality:2/5 Signal level:-78 dBm Noise level:-92 dBm IE: IEEE 802.11i/WPA2 Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : TKIP CCMP Authentication Suites (1) : PSK IE: Unknown: DDA20050F204104A0001101044000102103B00010310470010BC329E001DD811B28601722BC165753C1021001D48756177656920546563686E6F6C6F6769657320436F2E2C204C74642E1023001C48756177656920576972656C6573732041636365737320506F696E74102400065254323836301042000831323334353637381054000800060050F204000110110009487561776569415053100800020084103C000100 IE: WPA Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : TKIP CCMP Authentication Suites (1) : PSK Encryption key:on Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 9 Mb/s 18 Mb/s; 36 Mb/s; 54 Mb/s; 6 Mb/s; 12 Mb/s 24 Mb/s; 48 Mb/s Cell 05 - Address: 00:12:BF:3F:0A:8A ESSID:"CnDStudios" Mode:Managed Frequency:2.412 GHz (Channel 1) Quality:5/5 Signal level:-47 dBm Noise level:-95 dBm IE: WPA Version 1 Group Cipher : TKIP Pairwise Ciphers (1) : TKIP Authentication Suites (1) : PSK Encryption key:on Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 22 Mb/s 6 Mb/s; 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s 36 Mb/s; 48 Mb/s; 54 Mb/s Cell 06 - Address: 00:1C:A8:6E:84:32 ESSID:"AIR_TIES" Mode:Managed Frequency:2.462 GHz (Channel 11) Quality:5/5 Signal level:-56 dBm Noise level:-98 dBm IE: IEEE 802.11i/WPA2 Version 1 Group Cipher : CCMP Pairwise Ciphers (1) : CCMP Authentication Suites (1) : PSK Encryption key:on Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 22 Mb/s 6 Mb/s; 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s 36 Mb/s; 48 Mb/s; 54 Mb/s Cell 07 - Address: 54:E6:FC:B0:3C:E9 ESSID:"tilda_biri_yeni" Mode:Managed Frequency:2.437 GHz (Channel 6) Quality:1/5 Signal level:-85 dBm Noise level:-99 dBm Encryption key:on Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s 12 Mb/s; 24 Mb/s; 36 Mb/s; 9 Mb/s; 18 Mb/s 48 Mb/s; 54 Mb/s Cell 08 - Address: 18:28:61:16:57:C3 ESSID:"obilet" Mode:Managed Frequency:2.437 GHz (Channel 6) Quality:1/5 Signal level:-88 dBm Noise level:-99 dBm IE: IEEE 802.11i/WPA2 Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : CCMP TKIP Authentication Suites (1) : PSK IE: WPA Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : CCMP TKIP Authentication Suites (1) : PSK Encryption key:on Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s 24 Mb/s; 36 Mb/s; 54 Mb/s; 6 Mb/s; 9 Mb/s 12 Mb/s; 48 Mb/s Cell 09 - Address: 00:1A:2A:60:BF:61 ESSID:"PROGEDA" Mode:Managed Frequency:2.462 GHz (Channel 11) Quality:2/5 Signal level:-75 dBm Noise level:-98 dBm IE: WPA Version 1 Group Cipher : TKIP Pairwise Ciphers (1) : TKIP Authentication Suites (1) : PSK Encryption key:on Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 22 Mb/s 6 Mb/s; 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s 36 Mb/s; 48 Mb/s; 54 Mb/s eth0 Interface doesn't support scanning.

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  • Tunneling in IPv6:

    - by JoesyXHN
    Hi, The concept of 6to4 tunneling is to do encapsulate and descapsulate an ipv6 packet through ipv4 network. The encapsulation process is: [IPv6 header][Transport Header][Application Protocol data] = encapsulation: [Ip4 Header][IPv6 header][Transport Header][Application Protocol data] I am talking from this infrastructure: Host A (IPv6) - Router R1 (dual stack) - Ipv4 net work - Router R2 (dual stack) - Host B (Ipv6) packet. The Ipv4 header in the encapsulation, which Ipv4 header is this among: Host A, Router R1, Router R2 and Host B? Thanks in advance.

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  • What does it mean whether network device is Loopback?

    - by Gtker
    Does it mean that the Loopback device handles the request like ping localhost ? If so, there should be at least one device that's loopback,but seems none of my two network device is Loopback: rpcap://\Device\NPF_{45D5ADA0-095E-49F3-BEA1-E8754390F2D4} Description: Network adapter 'Intel(R) PRO/Wireless 2200BG Network Conne ction (Microsoft's Packet Scheduler) ' on local host Loopback: no rpcap://\Device\NPF_{783C5467-4026-473C-86A0-5E5A3708C624} Description: Network adapter 'Realtek RTL8169/8110 Family Gigabit Ethern et NIC (Microsoft's Packet Scheduler) ' on local host Loopback: no Can someone clarify all this?

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  • Drag-to-disc CD or DVD writing software?

    - by Jeremy Rudd
    I just came to know about packet writing, which enables files to be written to disc one-by-one, instead of "burning" a whole disc all at once. After some initial searches all I've come up with is: Roxio Creator - includes DirectCD Nero Suite - includes InCD I'm looking for a functional CD/DVD packet writing software for Windows, without the extra bloat. Do you know of any?

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  • Problems with MGCP proxy creation

    - by Popof
    Hi, I'm trying to bypass my ISP router with my FreeBSD server (I've an optical connection so I've a RJ45 used to connect the box to WAN) Internet and TV are working fine (Using igmpproxy to forward TV stream) but I've a problem with phone. ISP's box is connected to the server which gives it a LAN address. The problem is that when the box builds MGCP packets (and especially SDP ones) it uses its LAN address. So I've think of writing an UDP proxy to handle MGCP and SDP packets in order to replace LAN address with server WAN address and then forward packet to WAN. Before starting coding I've captured stream packets using my server as a bridge between WAN connection and the ISP's box. And, in order to see if my solution is viable, I've tried to send those packets to the box using nemesis. I tried to send a packet (found in capture) containing an endpoint audit: AUEP 1447 aaln/[email protected] MGCP 1.0 F: A In the wireshark capture the box replied: 200 1447 OK A: a:PCMU;PCMA;G726-16;G726-24;G726-32;G726-40;G.723.1-5.3;G.723.1-6.3;G729;TELEPHONE-EVENT, fmtp:"TELEPHONE-EVENT 0-15,144,149,159", p:10-30, b:4-40, e:on, t:00, s:on, v:L;M;G;D, m:sendonly;recvonly;sendrecv;inactive;confrnce;replcate;netwtest;netwloop, dq-gi But when I use nemesis, I got an ICMP error: Port unreachable (Type 3, Code 3). To build this packet, WAN source address of the capture is replaced with my server LAN address, using the mgcp-callagent port (2727) and the packet is sent to the LAN address of the box at mgcp-gateway port (2427). The command I use is nemesis udp -S 192.168.2.1 -D 192.168.2.2 -x 2727 -y 2427 -P packet_to_send. I also tried an UDP scan to the box on callagent and gateway port: PORT STATE SERVICE 2727/udp open|filtered unknown 2427/udp closed unknown I found those results a little bit strange because it should be the 2427 port opened, as it was in capture. Internet Protocol, Src: <ISP MGCP Server>, Dst: <My WAN Address> User Datagram Protocol, Src Port: mgcp-callagent (2727), Dst Port: mgcp-gateway (2427) Does someone has any idea about how having my box responding to my requests ? Thanks in advance and sorry for my english.

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  • Wake On LAN on request

    - by honzas
    Hi, I have a small home network with the router capable of running OpenWRT, is there some utility or firewall rule, which can be used to Wake On LAN on request. What I think - if I want to access my media centre (using for example SSH or HTTP) and it is suspended, is it possible to catch the ICMP packet (saying the machine is offline) and send the WOL packet to wakeup the machine and resend the SSH or HTTP request? Thanks

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  • route http and ssh traffic normally, everything else via vpn tunnel

    - by Normadize
    I've read quite a bit and am close, I feel, and I'm pulling my hair out ... please help! I have an OpenVPN cliend whose server sets local routes and also changes the default gw (I know I can prevent that with --route-nopull). I'd like to have all outgoing http and ssh traffic via the local gw, and everything else via the vpn. Local IP is 192.168.1.6/24, gw 192.168.1.1. OpenVPN local IP is 10.102.1.6/32, gw 192.168.1.5 OpenVPN server is at {OPENVPN_SERVER_IP} Here's the route table after openvpn connection: # ip route show table main 0.0.0.0/1 via 10.102.1.5 dev tun0 default via 192.168.1.1 dev eth0 proto static 10.102.1.1 via 10.102.1.5 dev tun0 10.102.1.5 dev tun0 proto kernel scope link src 10.102.1.6 {OPENVPN_SERVER_IP} via 192.168.1.1 dev eth0 128.0.0.0/1 via 10.102.1.5 dev tun0 169.254.0.0/16 dev eth0 scope link metric 1000 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.6 metric 1 This makes all packets go via to the VPN tunnel except those destined for 192.168.1.0/24. Doing wget -qO- http://echoip.org shows the vpn server's address, as expected, the packets have 10.102.1.6 as source address (the vpn local ip), and are routed via tun0 ... as reported by tcpdump -i tun0 (tcpdump -i eth0 sees none of this traffic). What I tried was: create a 2nd routing table holding the 192.168.1.6/24 routing info (copied from the main table above) add an iptables -t mangle -I PREROUTING rule to mark packets destined for port 80 add an ip rule to match on the mangled packet and point it to the 2nd routing table add an ip rule for to 192.168.1.6 and from 192.168.1.6 to point to the 2nd routing table (though this is superfluous) changed the ipv4 filter validation to none in net.ipv4.conf.tun0.rp_filter=0 and net.ipv4.conf.eth0.rp_filter=0 I also tried an iptables mangle output rule, iptables nat prerouting rule. It still fails and I'm not sure what I'm missing: iptables mangle prerouting: packet still goes via vpn iptables mangle output: packet times out Is it not the case that to achieve what I want, then when doing wget http://echoip.org I should change the packet's source address to 192.168.1.6 before routing it off? But if I do that, the response from the http server would be routed back to 192.168.1.6 and wget would not see it as it is still bound to tun0 (the vpn interface)? Can a kind soul please help? What commands would you execute after the openvpn connects to achieve what I want? Looking forward to hair regrowth ...

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  • What happens when ARP Request comes from a different subnet?

    - by gsinha
    What will happen when an ARP Request packet is sent from router1 to router2 in the following two cases? Will an ARP Reply be generated or the ARP Request packet be dropped? [router1]Intf1(20.0.0.1/24) ======== (40.0.0.1/24)Intf2[router2] [router1]Intf1(20.0.0.1/24) ======== (20.0.0.2/8) Intf2[router2] The topology above have a port "Intf1" on router "router1" connected a port "Intf2" on another router "router2" via a direct link(eg, a 1 Gbps cable).

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