mac上本地网络传输问题

deletex

1. 
   
2. 在我的Mac电脑中，以太网网卡的ip为:10.3.48.82
   
3. 使用iperf -s 启动服务器
   
4. 使用iperf -c 10.3.48.82 -n 131072 进行测试，不到1秒就传完，131072 = 128K
   
5. 使用iperf -c 10.3.48.82 -n 131073 进行测试，需要34秒传完，131073 = 128K + 1
   
6. 
   
7. 以下是相关指令的执行结果，所有操作均在该Mac电脑上，请问为什么会这样
   
8. 
   
9. =================================================================================
   
10. 执行命令：ifconfig
    
11. lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 1500
    
12. options=3<RXCSUM,TXCSUM>        
    
13. inet 127.0.0.1 netmask 0xff000000
    
14. nd6 options=1<PERFORMNUD>
    
15. gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
    
16. stf0: flags=0<> mtu 1280
    
17. en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    
18. options=10b<RXCSUM,TXCSUM,VLAN_HWTAGGING,AV>
    
19. ether xx:xx:xx:xx:xx:xx
    
20. inet 10.3.48.82 netmask 0xffffff00 broadcast 10.3.48.255
    
21. nd6 options=1<PERFORMNUD>
    
22. media: autoselect (100baseTX <full-duplex>)
    
23. status: active
    
24. en1: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
    
25. ether xx:xx:xx:xx:xx:xx
    
26. nd6 options=1<PERFORMNUD>
    
27. media: autoselect
    
28. status: active
    
29. bridge100: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    
30. options=3<RXCSUM,TXCSUM>
    
31. ether xx:xx:xx:xx:xx:xx
    
32. inet 192.168.2.1 netmask 0xffffff00 broadcast 192.168.2.255
    
33. Configuration:
    
34. id 0:0:0:0:0:0 priority 0 hellotime 0 fwddelay 0
    
35. maxage 0 holdcnt 0 proto stp maxaddr 100 timeout 1200
    
36. root id 0:0:0:0:0:0 priority 0 ifcost 0 port 0
    
37. ipfilter disabled flags 0x2
    
38. member: en1 flags=3<LEARNING,DISCOVER>
    
39. ifmaxaddr 0 port 5 priority 0 path cost 0
    
40. media: autoselect
    
41. status: active
    
42. 
    
43. 
    
44. 
    
45. =================================================================================
    
46. 执行命令：iperf -s
    
47. ------------------------------------------------------------
    
48. Server listening on TCP port 5001
    
49. TCP window size:  128 KByte (default)
    
50. ------------------------------------------------------------
    
51. [  4] local 10.3.48.82 port 5001 connected with 10.3.48.82 port 52100
    
52. [  5] local 10.3.48.82 port 5001 connected with 10.3.48.82 port 52101
    
53. [ ID] Interval       Transfer     Bandwidth
    
54. [  4]  0.0-41.2 sec   128 KBytes  25.5 Kbits/sec
    
55. 
    
56. 
    
57. 
    
58. =================================================================================
    
59. 第一次执行命令:iperf -c 10.3.48.82 -n 131072
    
60. ------------------------------------------------------------
    
61. Client connecting to 10.3.48.82, TCP port 5001
    
62. TCP window size:  129 KByte (default)
    
63. ------------------------------------------------------------
    
64. [  4] local 10.3.48.82 port 52100 connected with 10.3.48.82 port 5001
    
65. [ ID] Interval       Transfer     Bandwidth
    
66. [  4]  0.0- 0.0 sec   128 KBytes  30.0 Gbits/sec
    
67. 
    
68. 
    
69. 
    
70. =================================================================================
    
71. 第二次执行命令:iperf -c 10.3.48.82 -n 131073
    
72. ------------------------------------------------------------
    
73. Client connecting to 10.3.48.82, TCP port 5001
    
74. TCP window size:  129 KByte (default)
    
75. ------------------------------------------------------------
    
76. [  4] local 10.3.48.82 port 52101 connected with 10.3.48.82 port 5001
    
77. [ ID] Interval       Transfer     Bandwidth
    
78. [  4]  0.0-34.3 sec   256 KBytes  61.1 Kbits/sec
    
79. 
    
80. 
    
81. 
    
82. =================================================================================
    
83. 内核参数：
    
84. net.inet.ip.fw.enable: 0
    
85. net.local.stream.sendspace: 65535
    
86. net.local.stream.recvspace: 65535
    
87. net.local.dgram.recvspace: 4096
    
88. net.inet.tcp.sendspace: 131072
    
89. net.inet.tcp.recvspace: 131072
    
90. net.inet.udp.recvspace: 196724
    
91. net.inet.raw.recvspace: 8192
    

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