hello list members, this is regarding linux tcp implementation .. if a tcp client application is requesting large receive window using setsockopt.. and is opening multiple connections to different servers... there is a possiblity that tcp buffers might get exhausted(in scenarios where there is lot of congestion or when a server is deliberately sending only some packets in the advertised window whereby the native tcp has to buffer all these packets before passing to the user, resulting in a DOS attack). Could u be more specific as how this would be a DOS attack? ->My question is whether linux tcp implementation deal with such situations by lowering the window sizes outgoing packets so that buffers will not get exhausted.... When application requested too much of buffer space, during connection establishment time, may be set to some default max value by systems. Use getsockopt to find the value. Modiying the window size once the connection is established, doesn't change the buffer space allocated. i have seen tcp_adv_win_scale and tcp_app_win of proc by which one can control the window sizes. 1st signifies size of the window+application buffer to isolate network from application latencies and scheduling. 2nd signifies size of the application buffer. ->how can one use these options to mitigate the aforesaid problems? and does this problem is automatically taken care of by linux stack... I might be missing some thing, if u are more specific abt the DOS attack that u see, I will try to explain. Correct me if I am wrong in ne of the above. cheers Suresh thanks and regards Syed -- ______________________________________________ IndiaInfo Mail - the free e-mail service with a difference! www.indiainfo.com Check out our value-added Premium features, such as an extra 20MB for mail storage, POP3, e-mail forwarding, and ads-free mailboxes! Powered by Outblaze -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
