How to make a tcp packet by our own using Ostinato software


Hello ,
I am working on Wiznet 812MJ module (having W5100 chip) .
I am trying to send a packet using Ostinato to my embedded board having this module connected with it through SPI .
In my case Ostinato shows packet send but on my side i am not getting any packet . Even the Flow graph doesn’t show 3 way hand shaking signals it only shows RST signal .
After looking for the solution for quite a while i got to know that this s/w doesn’t synchronise , it only sends the packet , Is this correct ??
In one case : I tried to send the TCP packets from PC1 to PC2 , my packets got correctly transmitted and received the correct data , then i could not understand why not with my board ?

waiting for reply


If you got the RST packet from your board, first check your board is listening correctly.
For the network debugging, I recommend to use the Wireshark (


When there is no listen port, W5100 send a RST packet.

You will check to write the listen port number correctly.
Becase W5100 have big-endian system, the lower address the higher value.
If you write listen port number 0x1122 of socket 0, you should write 0x11 to S0_PORT0 (at 0x0401) and write 0x22 to S0_PORT1(at 0x402).

thank you.