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Tra Cứu Tiêu Đề Giao Thức
Interactive 7 Protocols Hex ParserKhám phá tiêu đề giao thức HTTP/SMTP/DNS.
Field Details
Click on any field in the diagram to see details.
Ethernet II Header
14 bytes
0
8
16
24
32
40
48
56
Field boundary
Bit offset indicator
Ethernet II
| Field | Size | Description |
|---|---|---|
| Destination MAC | 6 bytes | Target hardware address |
| Source MAC | 6 bytes | Sender hardware address |
| EtherType | 2 bytes | Protocol type (0x0800=IPv4, 0x86DD=IPv6) |
IPv4 Header
| Field | Size | Description |
|---|---|---|
| Version | 4 bits | IP version (4) |
| IHL | 4 bits | Header length in 32-bit words |
| TOS | 1 byte | Type of Service / DSCP |
| Total Length | 2 bytes | Total packet size |
| TTL | 1 byte | Time to Live (hop limit) |
| Protocol | 1 byte | Next protocol (6=TCP, 17=UDP) |
| Checksum | 2 bytes | Header checksum |
TCP Header
| Field | Size | Description |
|---|---|---|
| Source Port | 2 bytes | Sender port number |
| Dest Port | 2 bytes | Receiver port number |
| Seq Number | 4 bytes | Sequence number |
| Ack Number | 4 bytes | Acknowledgment number |
| Data Offset | 4 bits | Header length / 4 |
| Flags | 9 bits | NS,CWR,ECE,URG,ACK,PSH,RST,SYN,FIN |
| Window | 2 bytes | Receive window size |
Common EtherTypes
| Value | Protocol |
|---|---|
0x0800 | IPv4 |
0x0806 | ARP |
0x86DD | IPv6 |
0x8100 | VLAN (802.1Q) |
What are Protocol Headers?
Protocol headers are structured data that precede the payload in network packets. They contain control information such as source and destination addresses, protocol types, sequence numbers, and checksums. Understanding header structure is essential for network debugging, packet analysis, and protocol implementation.
How to Use This Tool
Select a protocol from the tabs to view its header structure. Each colored block represents a field with its size indicated. Click on any field to see detailed information including field name and description, bit/byte offset, common values and their meanings, and RFC reference. Use the hex dump parser to analyze real packet captures by pasting hex output from tools like tcpdump or Wireshark.
Common Use Cases
Packet analysis to understand the structure of captured network traffic, protocol learning as a visual aid for studying network protocols, debugging to identify malformed headers or incorrect field values, and development reference when implementing network protocols.
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