Networking :: Cannot Receive UDP Multicast Packets From Windows
Dec 10, 2008
I've got an application that compiles in Windows and Linux and is using UDP multicast to communicate. I'm running it on a Windows machine, a Linux machine and a small board (Gumstix) that is running Linux as well. The Windows and Linux machines have no problems sending/receiving packets with each other. The Gumstix and Linux machines have no problems sending/receiving packets with each other. The Gumstix can also send/receive packets with two instances of the application both running on the Gumstix.
But when running on the Gumstix I can send udp multicast packets to Windows, but cannot receive them. (It works if I do point to point with a known IP port#, but not multicast.) I can run tcpdump on the Gumstix and see the packets, but they are not being received on my socket. Here's what tcpdump (running on the Gumstix) outputs when sending the same packet from different sources. Notice the IP header ID and flags (don't fragment) are different when coming from Windows.
WINDOWS to Gumstix
-7:-45:-2.015784 IP (tos 0x0, ttl 15, id 35331, offset 0, flags [none], proto: UDP (17), length: 444) 172.30.42.3.1165 > 239.255.183.180.47028: UDP, length 416
LINUX to GUMSTIX
-7:-43:-38.451991 IP (tos 0x0, ttl 15, id 0, offset 0, flags [DF], proto: UDP (17), length: 444) 172.30.42.13.32771 > 239.255.183.180.47028: UDP, length 416
GUMSTIX to GUMSTIX
-7:-33:-10.955608 IP (tos 0x0, ttl 15, id 0, offset 0, flags [DF], proto: UDP (17), length: 444) 172.30.42.110.1025 > 239.255.183.180.47028: UDP, length 416
I've tried everything I can think of to get this to work but am not getting anywhere. Also I'm pretty inexperienced when it comes to Linux. Anything I could try to be able to receive udp multicast packets from Windows?
We have a high speed udp multicast connection. There are about 37 multicast groups and average incoming rate via the connection is about 20000 pkt/sec and peak 40000+ pkt/sec. Each packet is about 100-300 bytes. And there are 6 busiest multicast groups generating 80% of the traffic. No significant outgoing traffic via that interface. The problem is that, if our heavy-weight application create 37 sockets for all the groups, the packet loss become quite frequent. but if we create the 6 sockets for the busiest groups, the packet loss drops to 1/10 of the original level. We can confirm that the lost packets DO arrive in our box because a light-weight recorder on another box on the same ethernet segment can see the lost packets when listening to the same groups. If we start another heavy-weight application for the rest groups (31 groups ) on the same box, the packet loss just come back to the original level.
The packet loss happens not only to the heavy-weight application but also the light-weight recorder running on the same system. that is, the loss is system wide. The socket kernel buffer are all 4MB max and did not observe system buffer overflow. It seems the number of sockets listening to the same multicast group have the most negative impact on packet loss. And the higher traffic have a far less impact on packet loss than the number of sockets. It also seems that there is some limit in the kernel that when socket number are reduced under, the packet loss can significantly ease. How can I further diagnose the problem? Our system is RHEL 5.3 32bit i386, Xeon 2.9GHZ 16 Processors, 32GB memory. Two broadcom giga netowrk card and 6 Intel GIGA NIC, and only one interface card has so much traffic.
For the last couple of days, I've been unsuccesfully trying to receive multicast packets on Ubuntu Server 11.04, and seen some strange things along the way. The program i use to test this, is basically http://www.scribd.com/doc/38224328/mcreceive-c.Now the network has been configured to forward me the multicast packets, regardless of the joins. So tcpdump shows me:
Code: 15:16:11.308952 IP 10.164.130.2.61417 > 224.16.17.23.47806: UDP, length 1400 ...
I'm trying to receive data that is being broadcast on address 224.0.1.1, 224.0.1.2, 224.0.1.3, 224.0.1.4. ports are 1201, 1202, 1203, 1204 respectively. I can see the data using wireshark but can not get my program to receive the data. all firewalls are shutdown. iptables is not running, i've set net.ipv4_icmp_ignore_broadcasts = 0 and still no luck.
I have just set up an FC 13 box for a small network application. At the core, the application is supposed to receive some data over a multicast on my local network. However, for some reason, I am not being able to receive any multicast data on this machine. Other machines, on the same network (connected on the same layer 2 switch) are receiving the multicast just fine. I have tried the following things:
1. ensure that I am joining the multicast on the correct interface: the machine has only one ethernet card. Also, after starting my application, I use netstat -g to check for group membership. The multicast subscription shows up fine.
2. ensure there is no error in the program: the program works fine on my person linux machine
3. ensure that the multicast is actually available: it is available on all other local machines. I also wrote my own small broadcaster. data from this broadcaster (running on the same box) is available to other machines but not to my own listener program.
4. no firewall/filtering settings on the layer2 switch
5. TTL setting on the broadcast: have tried changing it from 1 through 5 with no effect. Note that even if the broadcast is coming from the same machine, my machine does not pick it up while other machines on the network do so.
I suspect this has to do with some settings on the network card itself. Below is the output of /sbin/ifconfig on the card:
eth0 Link encap:Ethernet HWaddr 00:08:A1:67:BBA inet addr:192.200.20.32 Bcast:192.200.20.255 Mask:255.255.255.0 inet6 addr: fe80::208:a1ff:fe67:bbca/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Assume this: Machine A sends a packet to machine B, no application in machine B is waiting for the packet, Now: What happens in kernel? What happens to this packet exactly?
I am working on uClinux/almost same as Linux. I am new to socket programming. I have two micro controllers running on same code. Simple run with arguments mean send merged string. run 1st micro controller (Send): ./Name "anystring" run 2st micro controller (Recive):/Name
My code is: int receive() { // Create socket int sock_fd; struct sockaddr_in addr; char buffer[kBufferSize]; int bytes_received=0; int addr_len = sizeof(addr); printf("receive start "); sock_fd = socket(AF_INET, SOCK_DGRAM, 0); if ( sock_fd == -1 ) { printf("receive Create "); // Error occurred return 0; } printf("Res Create sucee "); // Create address from which we want to receive, and bind it memset(&addr, 0, sizeof(addr)); addr.sin_family = AF_INET; addr.sin_addr.s_addr = INADDR_ANY; addr.sin_port = htons(kPortNumber); if ( bind(sock_fd, (struct sockaddr*)&addr, sizeof(addr)) < 0 ) { printf("receive bind "); // Error occurred return 0; } printf("Bind Succeful sucee "); while ( 1 ) { // Receive a message, waiting if there's nothing there yet bytes_received = recvfrom(sock_fd, buffer, kBufferSize-0, 0, (struct sockaddr*)&addr, &addr_len); if ( bytes_received < 0 ) { // Error occurred printf("receive bytes "); return 0; } printf(" bytes_received succeful "); printf("Ressocketstring : %s ",buffer); memset(Ressocketstring,0x00 , sizeof(Ressocketstring)); strcpy(buffer,Ressocketstring); printf("Ressocketstring : %s ",Ressocketstring); printf(" "); printf("Hello Receive finished"); // Now we have bytes_received bytes of data in buffer. Print it! fwrite(buffer, sizeof(char), bytes_received, stdout); } } int transmit(char * data, int length) { int sock_fds[kMaxSockets]; // Obtain list of all network interfaces /* struct ifaddrs *addrs; if ( getifaddrs(&addrs) < 0 ) { // Error occurred return 0; } */ // Loop through interfaces, selecting those AF_INET devices that support broadcast, but aren't loopback or point-to-point struct sockaddr_in addr; int number_sockets = 0; struct hostent *he; /* const struct ifaddrs *cursor = addrs; while ( cursor != NULL && number_sockets < kMaxSockets ) { if ( cursor->ifa_addr->sa_family == AF_INET && !(cursor->ifa_flags & IFF_LOOPBACK) && !(cursor->ifa_flags & IFF_POINTOPOINT) && (cursor->ifa_flags & IFF_BROADCAST) ) { // Create socket*/ sock_fds[number_sockets] = socket(AF_INET, SOCK_DGRAM, 0); if ( sock_fds[number_sockets] == -1 ) // Error occurred { printf("Error Create "); return 0; } he = gethostbyname((char *)BCASTADDRESS) ; if (he==NULL ) {printf("Error gethostbyname "); herror("gethostbyname"); printf("Error host "); exit(1); } printf("Res He "); // Create address from which we want to send, and bind it memset(&addr, 0, sizeof(addr)); addr.sin_family = AF_INET; addr.sin_addr = *((struct in_addr *)he->h_addr);//((struct sockaddr_in *)cursor->ifa_addr)->sin_addr; addr.sin_port = htons(kPortNumber); if ( bind(sock_fds[number_sockets], (struct sockaddr*)&addr, sizeof(addr)) < 0 ) { // Error occurred printf("Error bind "); return 0; } // Enable broadcast int flag = 1; if ( setsockopt(sock_fds[number_sockets], SOL_SOCKET, SO_BROADCAST, &flag, sizeof(flag)) != 0 ) // Err occur { printf("Error Enable "); return 0; } number_sockets =1; printf("Succes 1 "); printf("transmit Create "); // Initialise broadcast address memset(&addr, 0, sizeof(addr)); addr.sin_family = AF_INET; addr.sin_addr.s_addr = INADDR_BROADCAST; addr.sin_port = htons(kPortNumber); // Send through each interface int i; for ( i=0; i<number_sockets; i++ ) { if ( sendto(sock_fds[i], data, length, 0, (struct sockaddr*)&addr, sizeof(addr)) < 0 ) { printf("Error Send "); // Error occurred return 0; } printf("Succes 2 "); } return 1; } void MergeMessage( ) { memset(socketstring,0x00,sizeof(socketstring)); sprintf(socketstring,"%s@%s@%s@%s@%s@%s@%s@%s@%s@%s@%s ",Tmeg.s1,Tmeg.s2,Tmeg.s3,Tmeg.s4,Tmeg.s5,Tm eg.s6,Tmeg.s7,Tmeg.s8,Tmeg.s9,Tmeg.s10,Tmeg.s11); printf(" MergeSocketMessage : %s ",socketstring); } int main (int argc, char** argv) { int fd=0,bdc=0; struct ifreq ifr; printf("Tsarting man "); fd = socket(AF_INET, SOCK_DGRAM, 0); strncpy(ifr.ifr_name, "eth0", IFNAMSIZ-1); ioctl(fd, SIOCGIFADDR, &ifr); close(fd); memset(MYIP,'-',sizeof(MYIP)); memset(BCASTADDRESS,'-',sizeof(BCASTADDRESS)); strcpy(MYIP, inet_ntoa(((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr)); printf("Etho: %s ,len:%d ", MYIP,strlen(MYIP)); for(bdc=strlen(MYIP);MYIP[bdc-1]!='.';bdc--) {} strncpy(BCASTADDRESS,MYIP,bdc-1); strcat(BCASTADDRESS,".255"); printf("BCASTADDRESS: %s ,len:%d ", BCASTADDRESS,strlen(BCASTADDRESS)); printf("Initial Broad Cast message "); { /*s0"0" (id=76) s1"500" (id=77)s2"100" (id=78)s3"100" (id=78)s4"startVD" (id=79) s5"lighting" (id=80)s6"reading" (id=81)s7"Anna" (id=82)s8"0" (id=76) s9"";s10"" (id=64)s11"" (id=64)*/ strcpy(Tmeg.s0,"0"); strcpy(Tmeg.s1,"500");strcpy(Tmeg.s2,"100");strcpy(Tmeg.s3,"100"); strcpy(Tmeg.s4,"startvd");strcpy(Tmeg.s5,"lighting");strcpy(Tmeg.s6,"reading"); strcpy(Tmeg.s7,"anna");strcpy(Tmeg.s8,"0"); } MergeMessage (Tmeg); if( strlen(argv[1]) ) { //strcpy(socketstring,Tmeg,sizeof(Tmeg)); if(transmit(socketstring, strlen(socketstring) ) ) { printf(""%s" transmitted. ", socketstring); } else { printf("Error occurred: %s ", strerror(errno)); return 1; } } else { for( ; ; ) { if ( argc < 2 ) // No argument: Just listen { printf("Listening... "); if ( !receive() ) { printf("Error occurred: %s ", strerror(errno)); return 1; } return 0; } } } printf("Finished "); return 0; } //////////////// .h file is ///////////// //#define WIN32_LEAN_AND_MEAN// Exclude rarely-used stuff from Windows headers #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <net/if.h> #include <fcntl.h> #include <netdb.h> #include <signal.h> #include <sys/wait.h> #include <sys/ioctl.h> #define SubLen50 //#include <ifaddrs.h> #include <errno.h> char MYIP[20]; char BCASTADDRESS[20]; typedef struct { char s0[SubLen]; char s1[SubLen]; char s2[SubLen]; char s3[SubLen]; char s4[SubLen]; char s5[SubLen]; char s6[SubLen]; char s7[SubLen]; char s8[SubLen]; char s9[SubLen]; char s10[SubLen]; char s11[SubLen]; }msg_struct; msg_struct Sendmsg; msg_struct Tmeg; //Recivemsg; Boolean pri[6]; char socketstring[SubLen*12]; char Ressocketstring[SubLen*12]; int kBufferSize = (SubLen*12);
I need to receive a number of raw ethernet packets (say, 100 packets) into a user-mode accessible buffer large enough to hold all the packets. The way I have done this so far is by looping over the recvfrom() system call 100 times, passing an incremented pointer addressing the location in my buffer to store the packet. Is there a way to receive the 100 packets into my buffer with one system call, perhaps by instructing the kernel to DMA the 100 packets into my buffer?
I am trying to do something outlandish with iptables (or so I think!).I have a source sending udp packets to a destination (say dst11). Using port mirroring I am able to get all these packets to a different machine (say dst22). I am able to see these packets on dst22 interface using tcpdump.I want to analyze the packets on dst22. So what I do is put dst22 interface in promiscuous mode (using ifconfig eth0 promisc). This in theory should get the packet through the MAC layer. Now using iptables I am trying to DNAT the packets in nat prerouting to change the packets destination IP to dst22's interface and change the destination port.
I'm having problems with my internet connection; it seems to be working fine then every other click of a page there is no connection, then I click it again a second later and it works. I am using a wired network connection plugged into an addon wireless router.
When I use ping under network tools it seems to be fine, then freezes halfway through and doesn't receive those few packets, giving me a transmission percentage of about 70%.
I am trying to build a socket to retrieve the ethernet packets from ECU(I do not know much about the ECU). When i run my code on windows there is no problem and the code runs correctly. But when i run my code on Debian it gets stuck at s.recv(1024).
I have already set static ip in /etc/network/interfaces as follows:
Code: Select all import socket import sys HOST = "160.48.199.91" port = 30490 s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_UDP) s.bind((HOST, 30490)) while True: data = s.recvfrom(1024) print(data)
There is no LAN or Router. When i check netstat -s i see that there are 0 UDP and 0 TCP messages received. But when i check in Wireshark on Debian i could see the displayed UDP packets. Does it mean that the UDP packets are reaching the Raspberry Pi but not received by Debian ? Or are these packets being dropped?
i have a linux server runnig oracle applications. i need to access this server from putty using ssh through internet. i did by registering my static ip with the dnydns.org and i am able to connect to the server. but now there is no security to authenticate any user as any one knowing the password can login to it.
i thought of configuring the firewall of linux server but the client ip`s are not static and they change continiously. so thought of keeping one more pc between the server and the router which will do the work of authenticating. but i am confuse as how to configure it to allow the packets coming from the internet after authenticating and to by pass the packets generated from internal LAN?
I have several multicast data feeds that I'm trying to connect to using a minimal server install of Ubuntu as a VM on a VMWare ESXi server.I have another VM on the same server running Solaris that can connect with no issues to the incoming multicast stream.
This is not a linux specific question more of a general network issue with the hope that someone may have already done this under linux.My problem:I have a red hat linux machine transmitting IP multicast packets onto an ethernet gigabit network (cisco switch).Wireshark (running on a different red hat linux box confirms packets on network.
If I have set up 2 network interfaces on a box, if I started sending multicast traffic, it will go out through both interfaces? Or is there a way to control through which interface it will go out?
I have a hardware device with two ethernet ports, eth0 and eth1 running Centos 5. Basically my goal is to forward packets from eth0->eth1 and eth1->eth0 as well as get a copy of these packets for analysis. If I set IP routing to do the forwarding then I won't get a copy of the packets for analysis.
I have 4 interfaces, dvb0_0 - dvb0_3. Each one has a multicast stream coming in on it. The program I am using to decode these streams only accepts one interface though. How can I "combine" so that the program, listening on 1 ip can get all 4 streams? they are on groups 224.0.1.1-4
In the ipv4 code i was using "ip_mc_join_group()" to join the multicast group. but i cannot find a similar function for ipv6 i have found one ipv6_sock_mc_join() but this function is not available for use with my module as it is not exported.
have a doubt about the multicast address.I have read that IP and ethernet multicast address have the same last 23 bits. While an ethernet multicast address always starts with 01:00:5E. Changing the last 23 bits of the IP address into hexadecimal form and "adding" them to the first 24 bits we find the ethernet address but what about the missing bit??? For istance I have: 230.11.111.10 = 11100110.00001011.01101111.00001010 So converting the last 23 bits I have b:6f:a The final ethernet address will be 01:00:5E:b:6f:a . And what about the missing bit?
I am trying to run some benchmark tests for multicast. What I want to do is have one system send multicast packets and another receive it on all it's interfaces (eth0-eth3). Whenever I run receiver on more than one interface I get echo effect (if I receive on x interfaces then I get same packet x number of times). Is this how it is supposed to behave? It does not make any difference whether I use loop-back or not. I have set SO_REUSEADDR to yes. I run separate instance of receiver on each interface. I am doing this on RHEL5 systems.
How can I find out list of multicast addresses and port in use?"netstat -ng" only gives list of multicast addresses that have been joined, it does not give port number.I have several hundred servers running application that listens to several multicast addresses on different ports. I want to write an audit script and get the list of multicast address and port numbers.
I have a PC connected by ethernet to a Galil motion controller card.I recently installed Centos 5.The Galil software for communicating with the card is reporting that it can't join a multicast socket group.The software used to work with another version of Linux.
I've just set up an LTSP server, with all its clients on a separate subnet to my main network - the main network is 192.168.1.x, and the LTSP clients are all 192.168.2.x. My LTSP server has 2 NICs, one on each network, and is merrily forwarding normal IP traffic from the clients to the rest of the network. I have a client/server application that has a server on one machine, and clients locate and attach to it using multicast protocols. The server is on the main network, and any other machines on the network can locate and talk to the server quite happily. The LTSP clients, however, cannot - I assume because the multicast communications aren't being forwarded by the LTSP server. How I can get this working?
When I have my IPTV inserted in the computer I am either having problems connecting to the internet or recieve the multicast streams from the iptv. I do get a valid ip on both the WAN and IPTV, but I am having problems getting them both to work at the same time.
Windows clients experience an issue of being unable to create folders inside the new share I setup. I do not want any share security on this folder since its a global share that our entire office houses client information. They can view the contents but not add it.
My smb.conf has the following settings on the share [global] log file = /var/log/samba/log.%m passwd chat = *Entersnews*spassword:* %n *Retypesnews*spassword:* %n *passwordsupdatedssuccessfully* .
I make an application on GNU/Linux which listening on a MULTICAST stream, so I open my unconnected socket, bind it on a MULTICAST address and a port, join the multicast group with the "setsockopt (IP_ADD_MEMBERSHIP)", then I receive datagram on my socket.
Now I've two different instances of the same application that run with their own MULTICAST address and port. And what I found strange is that, after a misconfiguration, I switch the ports, for example:
Emitting on 225.0.0.1/23451 and 225.0.0.2/23452 Receiving on 225.0.0.1/23452 and 225.0.0.2/23451
And my receiving part doesn't care about the MULTICAST address, it looks like the socket is listening on the port number only! I mean that the receiver [225.0.0.1/23452] take its datagrams from emitter [225.0.0.2/23452] and vice-versa!
My setup is...I have a wireless access point using laptop as a gateway. The AP is also connected to a switch as is the laptop. So the laptop has two interfaces one wireless and one wired. A third device is using the AP to connect to a server on the internet. The AP sends the packets to my laptop where they are dropped. I've been looking for a solution to this problem without success. Basically is there a way for my laptop to forward all packets it sees from a certain IP address to whatever destination address they have?To clarify, my laptop is just the gateway of the AP and none of the packets are addressed to it at all, it just picks them up using a sniffer or similar tool.
