all I get is the broadcast address can be used to send packets of information to all computers on a network simultaneously. Can that be used during MPI programming or anything of the such? What is the day to day use of the broadcast address?
View 3 RepliesHow do I calculate broadcast adrress if the address space is 192.168.36.16/28 then what would be broadcast address.
View 7 Replies View RelatedI dont know the difference between these topics.
View 1 Replies View RelatedFriends i have an idea to broadcast few local TV channels to the world via internet.But friends i can't directly broadcast from my country because of bandwidth.friends is there a way to do this through a remote server server? i just need to input my stream to a remote server and then broadcast it from the server.I can stream channels to the server from my country through a 10mbbs connection.
View 2 Replies View Relatedi m setting up a linux server and i have to setup ip , in static mode. so i know everything except those two things. how do i calculate them?
example ip:200.49.142.91
submask 255.255.255.248
gateway 200.49.142.89
I need to configure network. I have configured a labtop "1" as a wireless Access point. And connected 2 laptops. I want to broadcast from a labtop "2" a video and read it on labtop 3. This broadcast will be done first time using VLC server then using apache server.
View 2 Replies View RelatedI have a Dell Vostro 1400 with a BCM4311 Broadcom wireless card that I just reinstalled with 11.04 from 10.04. I have the drives installed and it seams to be working when i run the 'Additional Drives', but I can't get the wireless adapter broadcasting. I followed the instructions given in the knowledge base on installing Broadcom Wireless, to see if I could get it running and that is where I saw the difference between the example and my computer when writing the 'sudo lshw -C network' command. In the example it said it was broadcasting under configuration (just like my wired networks below) and in mine it does not (see below for copy past).
I can't find a tickbox in the systemtray to enable the wirless networking that I had before the update to 11.04 (the 'Enable Networking' tickbox is still there and the wired network works fine - that is how I got online to do this post). I have the hardware switch turned on and I have been in the BIOS and made sure that the Wireless is enabled.Anyone who knows what could be wrong? Where could I go from here?Quote:
morgan@morgan-Vostro-1400:~$ sudo lshw -C network
[sudo] password for morgan:
*-network UNCLAIMED
[code]....
I'm looking for a solution to broadcast messages on the network. All systems are Linux / Ubuntu.
It would be used in case the server has to be rebooted. It saves me a walk to every office in the building.
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.
View 4 Replies View RelatedI have a router and when my Debian machine connects I get "null" as the host name. How can I get it to display the host name?
View 11 Replies View RelatedHere is my problems :I have two networks :1. LAN (10.1.x.x subnet 255.255.0.0), and2. my internet public (IP 202.xx.xxx.xxxx subnet 255.255.255.240)I have an application in my LAN PC (10.1.2.240) which broadcast udp packet to its client. The client in my LAN can receive the udp packet, no problem.My question is how netcat/socat can RELAY the udp broadcast packet to one of my IP public address so the message can be received by other client from internet ?
View 5 Replies View RelatedLink 1 = my network [url]
My network:
Subnet 1
Subnet 2
When someone creates a network loop (a cat 5 cable is plugged into two ports on a switch), the 2 subnet get flooded and become very slow.
How can I prevent subnet 1 from getting flood if someone create a loop on subnet 2.
- eth2 go offline automatically until the network loop is canceled.
I am basically from system side and often confused about the calculation of the IP addresses.Just i want to know that what how can i calculate the following of a IP Address:
(1) Available IP in a Network
(2) Broadcast IP
(3) Network Prefix or Net Mask
if there is a simple wifi scanner for Linux. I need only basic information such as access points in the neighbourhood, signal strength and their broadcasting channels. I want to know the broadcasting channels in order to set my modem in such a way to avoid interference.
View 9 Replies View RelatedI'm using F15 with two nics, each on different subnets 192.168.1.0/25 and 192.168.1.128/25. My issue is that on boot my 192.168.1.2/25 interface sets a broadcast address of 192.168.1.255 which is incorrect I believe. Its broadcast should be 192.168.1.127. I've tried setting the broadcast param in ifcfg-p3p1 file "BROADCAST=192.168.1.127" with no benefit.I can change this after boot of course, but that removes my default gateway for some reason.
View 2 Replies View RelatedSo I just changed my network card settings recently, and I'm now getting no response when I ping the broadcast address for them... the cards are all connected through a switch with IP addresses 192.168.0.x, broadcast 192.168.0.255... ifconfig on all of them shows UP BROADCAST RUNNING MULTICAST, but nobody responds to a broadcast packet. Any thoughts?
EDIT: Pinging each machine individually works fine.
When setting up an alias for eth0, the interface works as expected for normal traffic, but does not receive broadcast traffic.
Host 1's setup:
Code:
Pinging host 1's normal interface from host 2 works as expected:
Code:
Pinging host 1's alias interface from host 2 works as expected:
Code:
Broadcast pinging from host 2 only gets a reply from host 1's real interface (as well as some other uninteresting devices on the network):
Code:
I have confirmed by listening on both interfaces using netcat, and broadcasting using netcat, and again only the real interface receives data.
Is this by design, or is it possible to get interface aliases to receive broadcast traffic?
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 am on a 172.16.x.x network with about 60 Windows XP home and Vista home clients in a peer-to-peer workgroup that uses DHCP to assign addresses. About half the traffic on my LAN is netbios broadcast. I do not want to do a WINS server because I do not want to have to manually change the registry on every machine. This is only for local name resolution and I do not have any web servers or e-mail servers. I do not have access to a Windows server to use as a DNS server. I am on Debian and using BIND but am open to other suggestions.
View 1 Replies View RelatedCurrently my OS is Ubuntu 9.04 Jaunty Jackalope Desktop OS and my web server is Apache2. I have a public address 60.x.y.z and my pc local address is 10.x.y.z. I have a web app in my Apache2 which currently run in localhost(10.x.y.z).
I would like to enable the web app so that it could be browse from outside. I know there maybe some port forwarding process and some commands involved in order to do that. But I have no idea on the steps to do that.
Version 10.04 LTS. Installed desktop version and network worked but I needed a static IP address and the install configures for a DHCP configured address. I tried changing to static address using the System->Preferences->Network Connections application but was unable to get the system to come up with the network up.
So I manually modified the /etc/network/interfaces and the /etc/resolv.conf files. I restart the system but when I do an ifconfig, I don't see a configured IP address on eth0 (only the loopback address). If I run /sbin/ifup eth0 everything then works fine and ifconfig shows the correct address bound to eth0.
My files are as follows:
I'm running Ubuntu 10.10 and I'm having problems trying to assign it a static IP address. No matter what I put in the Preferences->Networking area (identifying the interface as Manual)... it still will query DHCP for an address if I run the dhclient command. I'm using to using ubuntu server where I just set the IP in the interfaces config file.
View 1 Replies View RelatedI have just installed FC12 on my machine - and gone Windows free for the first time ever. Now I do use various flavours of Linux on a daily basis but not from an installation/sys admin point of view so my questions here may seem a little basic but pleas eindulge me if you will!
Now, my network connection works perfectly well under the following scenarios.
1) FC12, wired to router
2) FC12, wireless, SSID broadcast enabled
3) Ubuntu (laptop), wireless, SSID broadcast DISABLED
The only scenario that does not work is FC12, wireless with SSID broadcast disabled.
I can only assume that it is an issue with my USB modem (a linksys WUSB54GS) since the same set-up works fine from my laptop running Ubuntu with an internal wireless card.
Now, I know from reading the forums that it's pretty easy to get around a disabled SSID broadcast but this is an itch I just have to scratch....what the hell is causing this problem?
nm-tool ouput is as follows:
I have tried using wpa_supplicant but I am not sure which driver I am using here - is it ndiswrapper per chance?
(Driver: rndis_wlan)
How I can connect once again to my wireless router with SSID broadcast turned off.
I am working on implementing a protocol on NS2.34 .I really need help to solve this problem . Actually , I don't now whether the problem is generated by the tcl code or the c++ code when I run the simulation, I get this result :
Code:
num_nodes is set 64
INITIALIZE THE LIST xListHead
34
45
channel.cc:sendUp - Calc highestAntennaZ_ and distCST_
highestAntennaZ_ = 1.5, distCST_ = 550.0
SORTING LISTS ...DONE!
code....
Consider the following program:
Code:
#include <stdio.h>
#include <stdint.h>
[code]...
I am running my own Postfix mail server. Some time ago I noticed that most email was rejected because of the server's dynamic IP address. So I got a fixed IP address. However then I noticed that some mails got rejected due to failing the reverse DNS check. So my ISP told me to get a range of IP addresses and they could then create a PTR record for one of those addresses. That is now running but it turns out that the IP address used for the PTR record is a ... dynamic IP address. So Spamhaus PBL rejects my emails again.
View 1 Replies View RelatedIn my job I use some ethernet embedded devices. They take an ip address from dhcp server or auto ip. I only know mac address.How can I obtain ip from mac address? In other words I need a rarp packet generator.
View 6 Replies View RelatedI have a few external IP's assigned to me by my ISP. I have IPcop as my router/firewall. I am wondering how to bind 1 of my external ip's to my internal ip address. So I do not have to port forward, etc. For Example, 77.77.77.77 to 192.168.1.123 and on the server it see's the external IP address.
View 2 Replies View RelatedI dont know for what reason, since 2 days, I started having this message whenever I try to start httpd.I commented "Listen 443", restarted httpd started correctly. I needed to comment "listen 443" in order to be able to start httpdWhat is strange is when I do
Code:
telnet mylinux 443
it responds
[code]...
how to assign a address to my ethernet card all the options available
View 1 Replies View Related