TWSD-1337 FTPS Upload Fails with “553 Could Not Create File”, Eventually Exhausting Port Numbers
Review Request #1175 — Created Nov. 18, 2025 and submitted
| Information | |
|---|---|
| weikai | |
| APV10 | |
| rel_apv_10_7, rel_apv_10_7_3, rel_apv_10_7_4,rel_apv_10_7_3_26_HSOL,rel_apv_10_7_3_29_HSOL | |
| TWSD-1337 | |
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| Reviewers | |
| kevin.poh, mingji, peteryeh | |
Root cause:
When the APV actively sends out an RST, it does not block the L7 application firewall.Solution:
Complete the missing cases.
Reproduce:
1. The VS port range is limited, for example a minimum range of 20 ports.
2. Upload two or more files at once using CoreFTP.
Incorrect file permissions on the FTP server, such as attempting to upload and overwrite a file without write access. Error: “553 Could not create file.”
3. The issue accumulates over time and eventually gets triggered.
Error: “425 insuffioent ports please try again later“
