[Winpcap-users] Suppressed Packets

[Gianluca Varenni]

It seems as though the D-Link card drops packets whole Ethertype/Len is > 
46, i.e. packets declaring an ethernet payload size greater than 46--> total 
packet size > 60. You are actually transmitting 60-byte packets, so it's 
possible that the DLINK network card discards those "truncated" packets.

Have you tried transmitting bigger packets (say 200 bytes) and see what 
happens? I guess the dlink card will receive only the packets with 
Ethertype/len < 186 (200-14) bytes.

Hope it helps
GV

----- Original Message ----- 
From: "Peter Hegel" <peter.hegel at doli.de>
To: <winpcap-users at winpcap.org>
Sent: Friday, October 20, 2006 6:01 AM
Subject: [Winpcap-users] Suppressed Packets


> Hi Winpcap team
>
> I've modified the sendpack.c demo to send out broadcast messages of 60 
> bytes. The content of the packet is set to zero. Only the length field is 
> incremented with each send.
>
>   /* set mac destination to BROADCAST FF:FF:FF:FF:FF:FF */
> packet[0]=-1;
> packet[1]=-1;
> packet[2]=-1;
> packet[3]=-1;
> packet[4]=-1;
> packet[5]=-1;
>
> /* set mac source to 2:2:2:2:2:2 */
> packet[6]=2;
> packet[7]=2;
> packet[8]=2;
> packet[9]=2;
> packet[10]=2;
> packet[11]=2;
>
>   for(i=0; i<1500; i++)
>   {
>     /* set 802.3 length field */
>     packet[12]=i/0x100;
>     packet[13]=i%0x100;
>
>     /* Send down the packet */
>     if (pcap_sendpacket(fp, packet, 60) != 0)
>     {
>       printf("\nError sending the packet\n");
>       return 3;
>     }
>   }
>
> Wireshark running on a second PC receives all (1500) packets, if I use a 
> 3COM NIC. With a D-LINK DFE-528T or a NETGEAR GA311 (both Gigabit NICs) 
> only packets with lenght fields less than 0x2F are captured by Wireshark.
>
> Any hints why D-LINK and NETGEAR Gigabit NICs don't work with my demo?
>
> I requested support from D-LINK already and will post results to the list.
>
>
> Thank you,
>
> Peter
> _______________________________________________
> Winpcap-users mailing list
> Winpcap-users at winpcap.org
> https://www.winpcap.org/mailman/listinfo/winpcap-users