Re: net.ipv4.tcp_max_syn_backlog implementation

2017-08-29 Thread Eric Dumazet
On Tue, 2017-08-29 at 11:05 -0400, Harsha Chenji wrote: > According to the man: > > The behavior of the backlog argument on TCP sockets changed with Linux > 2.2. Now it specifies the queue length for *completely established > sockets waiting to be accepted*, instead of the number of incomplete > c

Re: net.ipv4.tcp_max_syn_backlog implementation

2017-08-29 Thread Harsha Chenji
According to the man: The behavior of the backlog argument on TCP sockets changed with Linux 2.2. Now it specifies the queue length for *completely established sockets waiting to be accepted*, instead of the number of incomplete connection requests. The maximum length of the queue for incomplete s

Re: net.ipv4.tcp_max_syn_backlog implementation

2017-08-28 Thread Eric Dumazet
On Mon, 2017-08-28 at 23:47 -0400, Harsha Chenji wrote: > So I have ubuntu 12.04 x32 in a VM with syncookies turned off. I tried > to do a syn flood (with netwox) on 3 different processes. Each of them > returns a different value with netstat -na | grep -c RECV : > > nc -l returns 16 (netcat-

Re: net.ipv4.tcp_max_syn_backlog implementation

2017-08-28 Thread Willy Tarreau
On Mon, Aug 28, 2017 at 11:47:41PM -0400, Harsha Chenji wrote: > So I have ubuntu 12.04 x32 in a VM with syncookies turned off. I tried > to do a syn flood (with netwox) on 3 different processes. Each of them > returns a different value with netstat -na | grep -c RECV : > > nc -l returns 16 (

net.ipv4.tcp_max_syn_backlog implementation

2017-08-28 Thread Harsha Chenji
So I have ubuntu 12.04 x32 in a VM with syncookies turned off. I tried to do a syn flood (with netwox) on 3 different processes. Each of them returns a different value with netstat -na | grep -c RECV : nc -l returns 16 (netcat-traditional) apache2 port 80 returns 256 vsftpd on 21 returns 64.