Is port 123 (NTP) dangerous?

Port 123 is classified as low risk. This service uses encryption or has a minimal attack surface, making it relatively safe to expose with standard security practices.

Should port 123 be open on my firewall?

Port 123 is generally safe to have open. Apply standard security practices: keep software updated and monitor access logs.

What transport protocol does port 123 use?

Port 123 (NTP) uses the UDP transport protocol and falls under the System & Infrastructure category.

:123 (UDP)

NTP

Low 风险

UDP — System & Infrastructure

端口概览

端口号 123

服务名称 NTP

传输协议 UDP

类别 System & Infrastructure

安全风险 Low

端口范围知名端口 (0-1023)

什么是端口 123?

Network Time Protocol. Synchronizes clocks across networked computers with millisecond accuracy. Essential for logging, security certificates, and distributed systems.

UDP System & Infrastructure 常用

安全注意事项

端口123（NTP）被归类为低风险。该服务使用加密或攻击面极小，相对安全可以暴露。

建议：应用标准安全实践。保持软件更新并监控访问。

NTP

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端口概览

什么是端口 123?

安全注意事项

相关协议

相关端口 — System & Infrastructure

相关术语