Why does server miss the ack from client while tcp handshaker?

llclown · 04-12-2010, 10:10 PM

We have a problem with tcp link.
Os version: linux 2.6.9

Client will connect 2 tcp links to server.
One link is ok but another can't.

From tcpdump, we see:
1. client SYN-----> server
2. server SYN/ACK---> client
3. client ACK ----> server
4. client data ----> server
5. client retransmit data some times ----> server
6. server SYN/ACK ----> client (weird, it look like server miss the step 3)

Does anyone have some idea of this?

sagarkha · 04-13-2010, 02:22 AM

which applications you are using on client and server side? Is your client a browser connecting to a webserver?

cola · 04-13-2010, 07:10 AM

Quote:

Originally Posted by llclown

We have a problem with tcp link.
Os version: linux 2.6.9

Client will connect 2 tcp links to server.
One link is ok but another can't.

From tcpdump, we see:
1. client SYN-----> server
2. server SYN/ACK---> client
3. client ACK ----> server
4. client data ----> server
5. client retransmit data some times ----> server
6. server SYN/ACK ----> client (weird, it look like server miss the step 3)

Does anyone have some idea of this?

Post complete result of tcpdump from terminal.
And which linux distribution are you on?