Server sends out RST message on receipt of SYN from the client

[VijaySwaminathan]

Hi All, I'm trying to use Trex to send TCP Connection . I initiate a TCP connection from the client, the server receives the traffic from the client, but as soon as the server receives the SYN packet , it responds with RST . on the Server side, i could see the following error message "*server first flow packet with no SYN" Could not understand much from the error message. could someone kindly help me to resolve this issue pls?

[VijaySwaminathan]

[bdollma]

Hi Vijay, The error says it all, the first packet received by the server is not a SYN.

1. Do you have a middle box that manipulates the client packets or are Client and Server connected in Loopback?
2. Can you capture the RX packets in the server ports and very that they are arriving with SYN?
3. The total number of Tx packets is 30, however the total number of Rx packets is 69. Is the server receiving packets from some 3rd party? Thanks,