[Winpcap-users] my packets sent with winpcap can't reach NIC interface

Nawel Souissi nawelsouissi at yahoo.fr
Sat May 28 09:04:10 PDT 2011


Hello,

i'am using winpcap in my project.
i want to send packets from one computer to another computer.

i
 developped a transmitter application that uses winpcap to send packets 
to my NIC interface, and a receiver application that capture packets 
from NIC interface in another computer using winpcap.
the two cards are related with a cross wire.

but
 i have a problem here: the transmitter application prints "Packet is 
sent" but my receiver doesn't receive this packet (that i have sent)!!
i tested the receiver application and it works well if i relate it with another network.
the connexion between two cards is working well also i tested it with ping.

i
 even tried with wireshark, i sent a packet to my NIC interface and i 
started wireshark (installed in the same computer) and i want him to 
capture from this NIC interface but he prints "no packets".  means that
 packets are dropped before reaching the Ethernet card!!

i really need your help!! why my packets can't reach my Ethernet card?
this is my transmitter code:

pcap_if_t* ChosenDevice;
    pcap_t *fp;
    const char *InterfaceName;
    char errbuf[PCAP_ERRBUF_SIZE];
    int i = 1;

    pcap_findalldevs_ex(PCAP_SRC_IF_STRING,NULL,&ChosenDevice,errbuf);
    for(pcap_if_t* CurrentDevice = ChosenDevice;CurrentDevice != NULL;CurrentDevice = CurrentDevice->next)
    {
        cout<<i << ". "<<  CurrentDevice->description << endl;
        i++;
    }
    
    int chosen;
    cin >> chosen;

    if ( (fp= pcap_open(ChosenDevice->name,                  
                        1500,                           
                        PCAP_OPENFLAG_PROMISCUOUS,          
                        1000,                             // read timeout
                        NULL,                         // authentication on the remote machine
                        errbuf                       //
 error buffer
                        ) ) == NULL)
    {
        fprintf(stderr,"\nUnable to open the adapter. %s is not supported by WinPcap\n", InterfaceName);
        
    }
if(pcap_sendpacket(fp,Frame,Framesize)==0)
cout<<"packet is sent"<<endl;

and i used these functions is my receiver code:

pcap_findalldevs_ex(PCAP_SRC_IF_STRING, NULL, &alldevs, errbuf);
pcap_handle=pcap_open_live(d->name,20480,1,0,errbuf);
pcap_next_ex( pcap_handle, &paquet_header, &Paquet_Ethernet);


i think that i have a problem with some parameter in winpcap functions.
so how can i solve my
 problem?
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