네트워크 참조
DNS 레코드, 일반 포트, HTTP 상태 코드, 프로토콜 헤더를 하나의 탭형 도구에서 제공하는 네 가지 참조입니다.
DNS 레코드 참조
대화형DNS 레코드 유형에 대한 대화형 참조 자료입니다.
- 명령어 빌더
Description
Syntax Format
Example
Use Cases
TTL Recommendation
Security Notes
Command Builder
DKIM/SPF/DMARC use TXT records at specific subdomains.
dig example.com Anslookup -type=A example.comRoot Zone
The DNS hierarchy starts at the root (.) — 13 logical root name servers (a.root-servers.net through m.root-servers.net) handle queries for top-level domains.
Top-Level Domains (TLDs)
Managed by registries. Examples: .com, .org, .net (generic), .uk, .de (country-code), .app, .dev (new gTLDs). TLD servers delegate to authoritative name servers for each domain.
Authoritative Name Servers
These servers hold the actual DNS records for a domain. NS records point to them. They're the final authority for queries about that domain's records.
DNS Resolution Flow
- Stub resolver checks local cache
- Query recursive resolver (ISP or public DNS like 8.8.8.8)
- Recursive resolver queries root servers
- Root refers to TLD servers
- TLD refers to authoritative name servers
- Authoritative server returns the record
- Result is cached at each level
포트 참조
IANA 공식보안 위험 수준과 프로토콜 필터가 포함된 IANA 포트 데이터베이스입니다.
- 보안 플래그
- 클라이언트 전용
Search Ports
Quick Stats
Total Ports
0
Filtered
0
Results
| Port | Service | Protocol | Description | Risk |
|---|---|---|---|---|
| Start typing to search for ports... | ||||
Top 50 Most Common Ports
Port Number Ranges
| Range | Name | Description |
|---|---|---|
0-1023 | Well-Known | Reserved for system services (HTTP, SSH, etc.) |
1024-49151 | Registered | User-registered ports for applications |
49152-65535 | Dynamic/Private | Ephemeral ports for client connections |
High Risk Ports
| Port | Service | Risk |
|---|---|---|
21 | FTP | Unencrypted file transfers |
23 | Telnet | Plain text authentication |
25 | SMTP | Email spam relay risk |
53 | DNS | DDoS amplification attacks |
445 | SMB | Ransomware propagation |
3389 | RDP | Brute force attacks |
Security Best Practices
- Close unused ports: Reduce attack surface by disabling services you don't need
- Use firewalls: Implement network-level access controls
- Monitor traffic: Log connections to sensitive ports (22, 443, 3389)
- Prefer encrypted protocols: Use SSH (22) instead of Telnet (23), SFTP instead of FTP
- Change defaults: Consider non-standard ports for SSH/RDP (security through obscurity)
HTTP 상태 코드 참조
RFC 9110표준 HTTP 상태 코드를 사용 사례와 캐싱 지침과 함께 검색합니다.
- 검색 가능
- 브라우저에서 처리
Search HTTP statuses
Search by code, phrase, class, description, or when-to-use guidance.
Status codes
Showing all HTTP status codes.
Class meanings
| Class | Meaning | Typical use |
|---|---|---|
1xx | Informational | Interim responses while a request continues. |
2xx | Successful | The request was received, understood, and accepted. |
3xx | Redirection | The client needs another request or cached representation. |
4xx | Client Error | The request has a client-side problem or cannot be fulfilled. |
5xx | Server Error | The server failed to fulfill an apparently valid request. |
Safety, idempotency, and caching
Status codes do not make a request safe or idempotent by themselves. Safety and idempotency come from the request method and application semantics.
RFC caching rules allow some responses to be reused by default, including common statuses such as 200, 203, 204, 206, 300, 301, 308, 404, 405, 410, 414, and 501. Other statuses generally need explicit cache headers.
프로토콜 헤더 참조
HTTP/SMTP/DNS 프로토콜 헤더를 살펴봅니다.
Field Details
Click on any field in the diagram to see details.
Ethernet II Header
14 bytesEthernet 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) |