Need detail on TDI NBNS Request

Hi All,
I am trying to resolve short name in my TDI filter.
The short name is not resolvable in the local host/DNS.
I would like to pass this short name to the socks server for resolution.

I am getting ip xx.xx.xx.255 with port 137/138/139
response(RFC 1002/1003)in TDI_CONNECT for short name request frm IE.
Its a local broadcast address.

*Following steps I followed & working fine.*

  1. The NBNS request are filtered in the driver & sent to my SSLClient
  2. During Every application(IE) request, I am creating a listening
    socket for to accept data IN for
    the application & another socket to send data to my socks server.
  3. Read NBNS packet, Encrypted NBNS Request are converted in to text
    format (Decode Algorithm)
    to identify the short name request requested in the upper layer(IE).
    This details are available in RFC 1002 & 1003.
  4. The decoded short name sent to the socks server to resolve the same.
  5. Socks Server returning the resolved IP that are configured in the
    clean side DNS.

*Following are not working*
6. Formed NBNS response as per RFC 1001 & 1002. This packet formate is
not IP formate.
This contains 4bytes of header/flag(Not clear), Destination Ip,
Destination port , length of pkt, NBNS Response.
There is no source ip/port information. 90 % sure NBNS packet I
formed is correct except first 4 bytes.
If anybody know detail on this please send the info.
7. Using sentto command sent NBNS response packet to the upper
layer(Sent to listening loop back ip/port).
Shows No.of bytes sent with status success. I am trying to send the
NBNS response packet to the application that
requested the NBNS to give acknowledge. Before I send NBNS response
to the application(IE) requested,
IE is getting completed with “The Page Can not be displayed”. There
is no response on the NBNS response i sent to the
application. Pls give me detail regarding this.

In general the broadcast NBNS packets are sent to all PC’s, Whoever is
having a match on the short name will respond with NBNS response, But in
my application I am forming NBNS reply & there is no option to
get/specify source ip/port info.
I am specifying destination ip as & port as 137. Please give
me detail regarding this.

a. The packet received in the TDI level is not the exact Ethernet packet
format as we are looking in ethereal.
b. Partially some fields are identified & remaining are still i am
investigating(may be it represents NBNS request/flags).