[Winpcap-users] Problem with automatic modification of the length/type field of mac frames

[Guy Harris]

Eduardo Escudero Sánchez wrote:

> I have a program which constructs MAC frames and sometimees i have to 
> build frames with the length field set to a value less than the data 
> field length (because i have to add a pad to the data

You do?  Are you certain that the network adapter driver, or any common 
802.3 code it uses, won't do the padding for you?

Try sending the frame with no padding, and with the "size" argument to 
pcap_inject() or pcap_sendpacket() being the original data size.