TCP【四次挥手】#
数据包
- 客户端发送一个FIN、ACK给服务端，表示关闭连接。
Frame 52: 54 bytes on wire (432 bits), 54 bytes captured (432 bits) on interface -, id 0
Ethernet II, Src: NexoCommunic_00:04:01 (00:50:00:00:04:01), Dst: 50:00:00:07:00:00 (50:00:00:07:00:00)
Internet Protocol Version 4, Src: 192.168.1.10, Dst: 192.168.1.11
Transmission Control Protocol, Src Port: 80, Dst Port: 49706, Seq: 1, Ack: 2, Len: 0
Source Port: 80
Destination Port: 49706
[Stream index: 1]
[Conversation completeness: Complete, NO_DATA (23)]
[TCP Segment Len: 0]
Sequence Number: 1 (relative sequence number)
Sequence Number (raw): 682890236
[Next Sequence Number: 2 (relative sequence number)]
Acknowledgment Number: 2 (relative ack number)
Acknowledgment number (raw): 4033182580
0101 .... = Header Length: 20 bytes (5)
Flags: 0x011 (FIN, ACK)
Window: 502
[Calculated window size: 64256]
[Window size scaling factor: 128]
Checksum: 0xbf72 [unverified]
[Checksum Status: Unverified]
Urgent Pointer: 0
[Timestamps]
[SEQ/ACK analysis]
- 服务端收到FIN、ACK，返回ACK给客户端。
Frame 53: 54 bytes on wire (432 bits), 54 bytes captured (432 bits) on interface -, id 0
Ethernet II, Src: 50:00:00:07:00:00 (50:00:00:07:00:00), Dst: NexoCommunic_00:04:01 (00:50:00:00:04:01)
Internet Protocol Version 4, Src: 192.168.1.11, Dst: 192.168.1.10
Transmission Control Protocol, Src Port: 49706, Dst Port: 80, Seq: 2, Ack: 2, Len: 0
Source Port: 49706
Destination Port: 80
[Stream index: 1]
[Conversation completeness: Complete, NO_DATA (23)]
[TCP Segment Len: 0]
Sequence Number: 2 (relative sequence number)
Sequence Number (raw): 4033182580
[Next Sequence Number: 2 (relative sequence number)]
Acknowledgment Number: 2 (relative ack number)
Acknowledgment number (raw): 682890237
0101 .... = Header Length: 20 bytes (5)
Flags: 0x010 (ACK)
Window: 256
[Calculated window size: 65536]
[Window size scaling factor: 256]
Checksum: 0xc068 [unverified]
[Checksum Status: Unverified]
Urgent Pointer: 0
[Timestamps]
[SEQ/ACK analysis]
- 客户端收到ACK，发送一个FIN、ACK给服务端，表示关闭连接。
Frame 54: 54 bytes on wire (432 bits), 54 bytes captured (432 bits) on interface -, id 0
Ethernet II, Src: NexoCommunic_00:04:01 (00:50:00:00:04:01), Dst: 50:00:00:07:00:00 (50:00:00:07:00:00)
Internet Protocol Version 4, Src: 192.168.1.10, Dst: 192.168.1.11
Transmission Control Protocol, Src Port: 80, Dst Port: 49705, Seq: 306, Ack: 455, Len: 0
Source Port: 80
Destination Port: 49705
[Stream index: 0]
[Conversation completeness: Complete, WITH_DATA (31)]
[TCP Segment Len: 0]
Sequence Number: 306 (relative sequence number)
Sequence Number (raw): 1435287877
[Next Sequence Number: 307 (relative sequence number)]
Acknowledgment Number: 455 (relative ack number)
Acknowledgment number (raw): 1069963691
0101 .... = Header Length: 20 bytes (5)
Flags: 0x011 (FIN, ACK)
Window: 501
[Calculated window size: 64128]
[Window size scaling factor: 128]
Checksum: 0xb7bb [unverified]
[Checksum Status: Unverified]
Urgent Pointer: 0
[Timestamps]
[SEQ/ACK analysis]
- 服务端收到FIN，返回ACK给客户端。
Frame 55: 54 bytes on wire (432 bits), 54 bytes captured (432 bits) on interface -, id 0
Ethernet II, Src: 50:00:00:07:00:00 (50:00:00:07:00:00), Dst: NexoCommunic_00:04:01 (00:50:00:00:04:01)
Internet Protocol Version 4, Src: 192.168.1.11, Dst: 192.168.1.10
Transmission Control Protocol, Src Port: 49705, Dst Port: 80, Seq: 455, Ack: 307, Len: 0
Source Port: 49705
Destination Port: 80
[Stream index: 0]
[Conversation completeness: Complete, WITH_DATA (31)]
[TCP Segment Len: 0]
Sequence Number: 455 (relative sequence number)
Sequence Number (raw): 1069963691
[Next Sequence Number: 455 (relative sequence number)]
Acknowledgment Number: 307 (relative ack number)
Acknowledgment number (raw): 1435287878
0101 .... = Header Length: 20 bytes (5)
Flags: 0x010 (ACK)
Window: 255
[Calculated window size: 65280]
[Window size scaling factor: 256]
Checksum: 0xb8b1 [unverified]
[Checksum Status: Unverified]
Urgent Pointer: 0
[Timestamps]
[SEQ/ACK analysis]
