Default TCP Options creating problems
Subsystems (2)
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Quoted 11 lines · Nanda Kumar
Hi,
I am using Ubuntu 11.10 and unable to connect to my ISP login server. The same is working under windows. Under linux, ISP server does not respond TCP SYN packet even. I did a comparison of packet capture of windows and linux and found, linux include TCP options by default. After manually disabling TCP Timestamp via sysctl, the login is happening fine.
Quoted 4 lines
Is there any reason why TCP option is enabled by default? The same problem was happening under OpenSUSE 12.1
x86_64also. My friend informed me that his android mobile is also unable to connect to ISP login server.
I am very sorry, but you should complain to your ISP, 20 years after RFC 1323, it should support it.
TCP options are ... options, and as such should not be denied by a conformant TCP stack.
Hi Eric,
Quoted 14 lines · Eric Dumazet
Quoted 9 lines · Nanda Kumar
Hi,
I am using Ubuntu 11.10 and unable to connect to my ISP login server. The same is working under windows. Under linux, ISP server does not respond TCP SYN packet even. I did a comparison of packet capture of windows and linux and found, linux include TCP options by default. After manually disabling TCP Timestamp via sysctl, the login is happening fine.
Quoted 4 lines
Is there any reason why TCP option is enabled by default? The same problem was happening under OpenSUSE 12.1
x86_64also. My friend informed me that his android mobile is also unable to connect to ISP login server.
Quoted 9 lines
I am very sorry, but you should complain to your ISP, 20 years after RFC 1323, it should support it.
TCP options are ... options, and as such should not be denied by a conformant TCP stack.
Thank you for the reply. Yes even I feel so. I have put up this issue to ISP.
However this issue is happening only with TCP timestamp option. All other options are working fine. Any idea?
Regards,
Nandakumar
Quoted 6 lines · Nanda Kumar
Thank you for the reply. Yes even I feel so. I have put up this issue to ISP.
However this issue is happening only with TCP timestamp option. All other options are working fine. Any idea?
If you disable all options but tcp timestamps, what happens ?
Quoted 1 line · Eric Dumazet
If you disable all options but tcp timestamps, what happens ?
No, it doesn't work. I disabled SACK and window scaling. The connection gets established immediately once I disable tcp_timestamps. It may be problem with ISP. I am still awaiting their response. Not sure what sort of filtering they use for TCP Timestamps.
Thank you for your time.
Regards,
Nandakumar