tcpdump win

 win window

win--就是告诉对方自己能接受多大的数据。

Window is the number of bytes of receive buffer space available the other direction on this connection.

import socket
import time
s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
SEND_BUF_SIZE = 13
RECV_BUF_SIZE = 19
s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.setsockopt( socket.SOL_SOCKET, socket.SO_SNDBUF, SEND_BUF_SIZE)
s.setsockopt( socket.SOL_SOCKET, socket.SO_RCVBUF, RECV_BUF_SIZE)
print s.getsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF)
print s.getsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF)


C:Python27python.exe C:/Users/TLCB/PycharmProjects/untitled2/http/t5.py
19
13

RECV_BUF_SIZE 19
客户端定义SEND_BUF_SIZE 13





node1:/root#tcpdump -S -i eth1 '((tcp) and  (port 8080) and (host 192.168.137.1))'
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth1, link-type EN10MB (Ethernet), capture size 65535 bytes
05:47:27.887156 IP 192.168.137.1.56605 > node1.webcache: Flags [S], seq 476814817, win 19, options [mss 1460,nop,wscale 2,nop,nop,sackOK], length 0
05:47:27.887200 IP node1.webcache > 192.168.137.1.56605: Flags [S.], seq 2829851870, ack 476814818, win 1536, options [mss 256,nop,nop,sackOK,nop,wscale 6], length 0
05:47:27.887384 IP 192.168.137.1.56605 > node1.webcache: Flags [.], ack 2829851871, win 4, length 0


05:47:27.889388 IP 192.168.137.1.56605 > node1.webcache: Flags [P.], seq 476814818:476814823, ack 2829851871, win 4, length 5
05:47:27.889858 IP node1.webcache > 192.168.137.1.56605: Flags [.], ack 476814823, win 24, length 0
05:47:27.890020 IP node1.webcache > 192.168.137.1.56605: Flags [P.], seq 2829851871:2829851885, ack 476814823, win 24, length 14
05:47:27.890227 IP 192.168.137.1.56605 > node1.webcache: Flags [R.], seq 476814823, ack 2829851885, win 0, length 0


查看wireshark: