連接埠檢測器
檢測某個TCP連接埠是否開放並接受來自網際網路的連線。
如何使用本工具
- 1
Type the public hostname or IP you want to probe (for example example.com) into the host field.
- 2
Set the port number, either by typing it or clicking one of the quick presets like 22, 80, 443, or 3306.
- 3
Click Check and wait up to five seconds for the result.
- 4
Read the result banner: green means the port accepted a TCP connection (with latency in milliseconds), red means it did not (with the reason code).
什麼是連接埠檢測器？
網路服務在TCP連接埠上監聽：Web伺服器在80/443，SSH在22，資料庫在3306/5432。如果某個連接埠被關閉或受防火牆保護，則任何連線都無法成功。本工具會嘗試從我們的伺服器向你指定連接埠上的主機開啟一個TCP通訊端：這對於偵錯防火牆規則、驗證服務是否確實對外暴露或稽核安全性很有用。
常見使用場景
Confirm a freshly deployed web app is reachable on port 443 before pointing DNS or a load balancer at it.
Diagnose why clients cannot connect to a database by checking whether 3306 or 5432 is actually exposed.
Verify a new firewall or security-group rule opened (or closed) the port you intended.
Check that a sensitive service like Redis on 6379 or MongoDB on 27017 is NOT left open to the public internet.
Test whether an outbound SSH or SMTP port is blocked between a remote host and the public internet.
Validate that a port-forward or reverse proxy is passing traffic through to the expected backend port.