Tcp offloading --- incorrect checksum

z_haseeb · 04-17-2020, 11:07 AM

I am able to telnet on a port at remote machine. However, I am unable to send packets on a connected socket. I run the command (ethtool -k rx off tx off) and then I am able to send packets on same connected socket and then application working accurately.

My Query is, why I need to off rx and tx ?

rtmistler · 04-18-2020, 04:28 AM

There's not enough information.

Disabling checksums is the answer for now.

z_haseeb · 04-18-2020, 08:18 AM

Thanks for your words rtmistler

How can we troubleshoot the packets travel on a connected socket ?

Disabiling checksum have put any impact on socket usually ?

When we disable the checksum, then does cpu calculate checksum ?

rtmistler · 04-18-2020, 08:52 AM

Quote:

Originally Posted by z_haseeb

Thanks for your words rtmistler

How can we troubleshoot the packets travel on a connected socket ?

Disabiling checksum have put any impact on socket usually ?

When we disable the checksum, then does cpu calculate checksum ?

Use a network sniffer
No
Not unless the protocol stack was written poorly

What I meant by there's not enough information is that you don't describe exactly what's not working, and how you know what isn't working. You also don't indicate whether you're using a custom program or something standard.