FTP - File Transfer Protocol

What is FTP?

FTP stands for File Transfer Protocol. It’s a standard network protocol used to transfer files between a client and a server over a TCP/IP network, such as the internet or a local network.

What is the purpose of FTP?

• Uploading and downloading files between systems.

• Managing website files on a remote server.

• Backing up data to a remote location.

• Sharing large files that are too big for email.

• It provides a simple way to move files across systems, especially in web development and system administration.

How does it work?

• Client connects to FTP server – Using an FTP client (like FileZilla), the user connects to the server using a username and password.

• Authentication – The server verifies the credentials.

• File operations – The user can upload, download, rename, delete, or move files on the server.

• Connection closes – Once done, the client disconnects from the server.

• FTP uses two channels: 1. Command channel – For sending commands and responses 2. Data channel – For transferring actual files

Where is FTP used?

• Web hosting – To upload website files to a server.

• Corporate environments – For internal file sharing and backups.

• Software distribution – To provide downloadable files (e.g., drivers, updates).

• Remote administration – For managing files on remote systems.

Which OSI Layer does this protocol belong to?

• FTP operates at the Application Layer (Layer 7) of the OSI model.

• It provides file transfer services to applications and users.

• It relies on TCP (Layer 4) for reliable communication.

Topics in this section,

• Learnings in this section

• Terminology

• Version Info

• FTP Basic Setup on Ubuntu using IPv4

• FTP Basic Setup on Ubuntu using IPv6

• FTP Protocol Packet Details

• FTP Usecases

• FTP Basic Features

• FTP Feature : File Transfer

• FTP Feature : Authentication

• FTP Feature : Directory Operations

• FTP Feature : File Management

• FTP Feature : Modes of Transfer

• FTP Feature : Transfer Types

• FTP Feature : Multiple Platforms

• FTP Feature : Control & Data Channels

• FTP Feature : Logging & Auditing

• Reference links

Learnings in this section

• In this section, you are going to learn

Terminology

• Terminology

Version Info

• Version Info

FTP Version&RFC Details

FTP Version	FTP Version	Year	Core Idea / Contribution
FTP v1
	RFC 114	1971	First definition of FTP; basic file transfer over ARPANET.
	RFC 141	1971	First definition of FTP; basic file transfer over ARPANET.
	RFC 172	1971	Additional clarifications.
FTP v2
	RFC 265	1972	Revised protocol with structured commands and replies.
FTP v3
	RFC 354	1972	Improved reliability and functionality.
FTP v4
	RFC 454	1973	More complete FTP model with refined control and data channels.
FTP v5
	RFC 542	1973	Pre-standard stable draft with enhanced command sets.
FTP [Standard]
	RFC 765	1980	First formal FTP standard; complete protocol specification.
FTP v6 [Modern]
	RFC 959	1985	Finalized and modern FTP; passive mode, structured replies, etc.
	RFC 1123	1989	Defined FTP compliance for Internet hosts.
	RFC 1579	1994	Enabled FTP to work through firewalls and NATs.
	RFC 2228	1997	Introduced AUTH, MIC, CONF, ENC for secure authentication.
	RFC 2389	1998	FEAT and OPTS commands for capability discovery.
	RFC 2428	1998	EPRT and EPSV for IPv6 and better NAT handling.
	RFC 4217	2005	Secured FTP communication using TLS.
	RFC 5797	2010	Standardized method for tracking FTP extensions via IANA.

FTP Basic Setup on Ubuntu using IPv4

• Setup

FTP Basic Setup on Ubuntu using IPv6

• Setup

FTP Protocol Packet Details

FTP USER Command

S.No	Protocol Packets	Description	Size(bytes)
1	FTP USER Command	Used to initiate login by sending the username to the FTP server.	57
	Command	USER	4
	Arguments	Username	20
	Response Code	331 (Username OK, need password)	3
	Response Message	“User name okay, need password.”	30
	Data (Payload)	Text-based command sent over TCP port 21	0

FTP PASS Command

2	FTP PASS Command	Sends the password for authentication after the USER command.	51
	Command	PASS	4
	Arguments	Password	20
	Response Code	230 (User logged in) or 530 (Login incorrect)	3
	Response Message	“User logged in, proceed.”	24
	Data (Payload)	Text-based command sent over TCP port 21	0

FTP LIST Command

3	FTP LIST Command	Requests a directory listing from the server.	60
	Command	LIST	4
	Arguments	Optional directory path	20
	Response Code	150 (Opening data connection), 226 (Transfer complete)	3
	Response Message	“Here comes the directory listing.”	33
	Data (Payload)	Sent over control channel; actual listing sent over data channel	0

FTP RETR Command

4	FTP RETR Command	Requests to download a file from the server.	63
	Command	RETR	4
	Arguments	Filename	20
	Response Code	150, 226	3
	Response Message	“Opening BINARY mode data connection.”	36
	Data (Payload)	File data sent over a separate TCP data connection (port 20)	0

FTP STOR Command

5	FTP STOR Command	Requests to upload a file to the server.	63
	Command	STOR	4
	Arguments	Filename	20
	Response Code	150, 226	3
	Response Message	“Opening BINARY mode data connection.”	36
	Data (Payload)	File data sent over a separate TCP data connection (port 20)	0

FTP QUIT Command

6	FTP QUIT Command	Terminates the FTP session.	15
	Command	QUIT	4
	Arguments	None	0
	Response Code	221	3
	Response Message	“Goodbye.”	8
	Data (Payload)	Sent over control channel	0

FTP Data Packet

7	FTP Data Packet	Carries actual file or directory listing data.	1013
	Source Port	Usually port 20 (server)	2
	Destination Port	Random high port (client)	2
	Sequence Number	Managed by TCP	4
	Acknowledgment Number	Managed by TCP	4
	Flags	PSH, ACK	1
	Data (Payload)	File content or directory listing	1000

FTP Usecases

S.no	Use Case	Description
1	Website Deployment	Upload website files to a remote server.
2	Software Distribution	Provide downloadable files via FTP server example - Drives.
3	Data Backup	Automatically back up files to an off-site server.
4	File Sharing Across Network	Share large files not suitable for email.
5	IoT and Embedded Devices	Transfer logs or firmware updates.

FTP Basic Features

S.no	Feature	Description
1	File Transfer	Requires a username and password (for secure access).
		Also supports anonymous access (limited permissions).
2	Authentication	Requires a username and password (for secure access).
		Also supports anonymous access (limited permissions).
3	Directory Operations
		View directory contents (LIST, NLST commands).
		Change directories (CWD Change Working Directory).
		Create (MKD) and delete (RMD) directories.
4	File Management
		Rename (RNFR, RNTO commands).
		Delete files (DELE).
		Resume interrupted downloads (using REST command).
5	Modes of Transfer
		Active Mode: Server initiates data connection to client.
		Passive Mode: Client initiates both control and data connections (useful behind firewalls).
6	Transfer Types
		ASCII mode: For text files.
		Binary mode: For images, videos, executables, etc.
7	Multiple Platforms
		Works across platforms (Windows, Linux, macOS).
		Many clients available: FileZilla, WinSCP, command line, etc.
8	Control & Data Channels
		Uses separate channels for control (commands) and data (files).
		Port 21 for control, and dynamic ports for data.
9	Logging & Auditing	FTP servers can log user activity for auditing and debugging.

FTP Feature : File Transfer

File Transfer - Testcases

S.No	Test Case	Description	Expected Result
1	Connect to FTP Server	Attempt to connect to a valid FTP server	Connection successful
2	Invalid Server Address	Connect using an incorrect server address	Connection fails with error
3	Anonymous Login	Login using anonymous credentials	Login successful
4	Invalid Credentials	Login with wrong username/password	Login fails
5	Upload Small File	Upload a small text file	File uploaded successfully
6	Upload Large File	Upload a large file (e.g., 1GB)	File uploaded successfully
7	Download Existing File	Download a file that exists on the server	File downloaded successfully
8	Download Non-existent File	Attempt to download a file that doesn’t exist	Error message shown
9	Resume Interrupted Upload	Resume an upload after interruption	Upload resumes from last point
10	Resume Interrupted Download	Resume a download after interruption	Download resumes from last point
11	Passive Mode Transfer	Transfer file using passive mode	File transferred successfully
12	Active Mode Transfer	Transfer file using active mode	File transferred successfully
13	Upload Binary File	Upload a binary file (e.g., .exe)	File uploaded without corruption
14	Upload ASCII File	Upload a text file in ASCII mode	File uploaded correctly
15	File Overwrite Prompt	Upload a file with same name	Prompt to overwrite or rename
16	File Rename on Upload	Rename file during upload	File uploaded with new name
17	File Rename on Download	Rename file during download	File saved with new name
18	Upload with Special Characters	Upload file with special characters in name	File uploaded successfully
19	Upload with Long Filename	Upload file with long name (>255 chars)	Error or successful upload
20	Transfer Timeout	Simulate network timeout during transfer	Transfer fails with timeout error
21	Transfer Retry	Retry file transfer after failure	Transfer resumes or restarts
22	Upload to Non-existent Directory	Upload to a directory that doesnt exist	Error or directory created
23	Download from Non-existent Directory	Download from invalid directory	Error message shown
24	File Permission Denied	Upload to a restricted directory	Permission denied error
25	Concurrent Uploads	Upload multiple files simultaneously	All files uploaded successfully
26	Concurrent Downloads	Download multiple files simultaneously	All files downloaded successfully
27	File Integrity Check	Verify checksum after transfer	Checksums match
28	Upload Hidden File	Upload a hidden file (e.g., .env)	File uploaded successfully
29	Download Hidden File	Download a hidden file	File downloaded successfully
30	Upload Folder	Upload a folder with multiple files	All files uploaded
31	Download Folder	Download a folder	Folder and contents downloaded
32	Cancel Upload	Cancel an ongoing upload	Upload stops immediately
33	Cancel Download	Cancel an ongoing download	Download stops immediately
34	Upload with Limited Bandwidth	Upload under bandwidth limit	Upload completes slowly
35	Download with Limited Bandwidth	Download under bandwidth limit	Download completes slowly
36	Upload with Encryption (FTPS)	Upload using FTPS	File uploaded securely
37	Download with Encryption (FTPS)	Download using FTPS	File downloaded securely
38	Upload with SFTP	Upload using SFTP protocol	File uploaded successfully
39	Download with SFTP	Download using SFTP protocol	File downloaded successfully
40	Upload with Firewall Enabled	Upload with firewall restrictions	Transfer may fail or succeed
41	Download with Firewall Enabled	Download with firewall restrictions	Transfer may fail or succeed
42	Upload with Proxy	Upload using FTP proxy	File uploaded successfully
43	Download with Proxy	Download using FTP proxy	File downloaded successfully
44	Upload with Logging Enabled	Enable logging during upload	Logs show transfer details
45	Download with Logging Enabled	Enable logging during download	Logs show transfer details
46	Upload with File Lock	Upload a file that is locked	Upload fails with error
47	Download with File Lock	Download a locked file	Download fails or succeeds
48	Upload Duplicate Files	Upload same file multiple times	Files renamed or overwritten
49	Upload with Interrupted Network	Disconnect network mid-upload	Upload fails with error
50	Download with Interrupted Network	Disconnect network mid-download	Download fails with error

FTP Feature : Authentication

Authentication - Testcases

S.No	Test Case	Description	Expected Result
1	Valid Login	Login with correct username and password	Login successful
2	Invalid Username	Login with incorrect username	Authentication fails
3	Invalid Password	Login with incorrect password	Authentication fails
4	Empty Username	Attempt login with empty username	Authentication fails
5	Empty Password	Attempt login with empty password	Authentication fails
6	Both Fields Empty	Attempt login with empty username and password	Authentication fails
7	Case Sensitivity	Login with correct credentials but wrong case	Authentication fails
8	Special Characters in Username	Use special characters in username	Authentication fails or succeeds based on server rules
9	Special Characters in Password	Use special characters in password	Authentication succeeds if password is correct
10	Long Username	Use a very long username	Authentication fails or succeeds based on server limits
11	Long Password	Use a very long password	Authentication fails or succeeds based on server limits
12	SQL Injection Attempt	Try SQL injection in login fields	Authentication fails, input sanitized
13	Anonymous Login Allowed	Login using anonymous credentials	Login successful
14	Anonymous Login Disallowed	Attempt anonymous login when disabled	Authentication fails
15	Login with Expired Account	Use expired user credentials	Authentication fails
16	Login with Locked Account	Use credentials of a locked account	Authentication fails
17	Login with Disabled Account	Use credentials of a disabled account	Authentication fails
18	Login with Inactive Account	Use credentials of an inactive account	Authentication fails
19	Login with Multiple Sessions	Login from multiple clients simultaneously	All sessions authenticated if allowed
20	Login with IP Restriction	Login from unauthorized IP	Authentication fails
21	Login with Time Restriction	Login outside allowed time window	Authentication fails
22	Login with Role Restriction	Login with user not allowed FTP access	Authentication fails
23	Login with Correct Credentials After Failure	Retry login after failed attempt	Login successful
24	Login After Multiple Failures	Login after several failed attempts	Account may be locked or login succeeds
25	Login with Encrypted Password	Use encrypted password (e.g., FTPS)	Authentication successful
26	Login with Plaintext Password	Use plaintext password (FTP)	Authentication successful
27	Login with SFTP	Authenticate using SFTP protocol	Authentication successful
28	Login with FTPS	Authenticate using FTPS protocol	Authentication successful
29	Login with Invalid Port	Attempt login on wrong port	Connection fails
30	Login with Correct Port	Attempt login on correct port	Authentication successful
31	Login with Proxy	Authenticate via FTP proxy	Authentication successful
32	Login with VPN	Authenticate via VPN connection	Authentication successful
33	Login with Firewall Enabled	Authenticate with firewall restrictions	Authentication may fail or succeed
34	Login with Brute Force Attempt	Simulate brute force login	Account locked or blocked
35	Login with Captcha (if enabled)	Attempt login with captcha	Authentication succeeds if captcha passed
36	Login with MFA Enabled	Authenticate with multi-factor authentication	Authentication successful
37	Login with MFA Disabled	Authenticate without MFA	Authentication successful
38	Login with Certificate	Authenticate using client certificate	Authentication successful
39	Login with Invalid Certificate	Use invalid certificate	Authentication fails
40	Login with Expired Certificate	Use expired certificate	Authentication fails
41	Login with Revoked Certificate	Use revoked certificate	Authentication fails
42	Login with Public Key	Authenticate using SSH public key	Authentication successful
43	Login with Invalid Public Key	Use wrong public key	Authentication fails
44	Login with Password Policy Violation	Use password not meeting policy	Authentication fails
45	Login with Session Timeout	Login after session timeout	Re-authentication required
46	Login with Session Persistence	Maintain session after login	Session remains active
47	Login with Session Hijacking Attempt	Simulate session hijack	Session invalidated
48	Login with Logging Enabled	Enable logging during login	Login attempts logged
49	Login with Audit Trail	Ensure audit trail is recorded	Login recorded in audit logs
50	Login with Server Restart	Attempt login after server restart	Authentication successful

FTP Feature : Directory Operations

Directory Operations - Testcases

S.No	Test Case	Description	Expected Result
1	List Root Directory	List contents of root directory	Directory contents displayed
2	List Subdirectory	List contents of a subdirectory	Subdirectory contents displayed
3	List Empty Directory	List contents of an empty directory	No files/folders shown
4	Create New Directory	Create a new directory	Directory created successfully
5	Create Nested Directory	Create a directory inside another	Nested directory created
6	Create Directory with Special Characters	Use special characters in directory name	Directory created or error shown
7	Create Directory with Long Name	Use a name >255 characters	Error or directory created
8	Create Directory with Spaces	Use spaces in directory name	Directory created successfully
9	Create Duplicate Directory	Create a directory that already exists	Error or overwrite prompt
10	Delete Empty Directory	Delete a directory with no contents	Directory deleted successfully
11	Delete Non-empty Directory	Delete a directory with files	Error or recursive delete
12	Delete Non-existent Directory	Attempt to delete a directory that doesn’t exist	Error message shown
13	Rename Directory	Rename an existing directory	Directory renamed successfully
14	Rename to Existing Directory Name	Rename to a name that already exists	Error or overwrite prompt
15	Change to Existing Directory	Change working directory to a valid one	Directory changed successfully
16	Change to Non-existent Directory	Change to a directory that doesnt exist	Error message shown
17	Change to Parent Directory	Move up one level in directory tree	Directory changed successfully
18	Change to Root Directory	Move to root directory	Directory changed successfully
19	Upload File to Directory	Upload a file into a specific directory	File uploaded successfully
20	Download File from Directory	Download a file from a specific directory	File downloaded successfully
21	Directory Permission Denied	Try to access restricted directory	Permission denied error
22	Directory Listing with Passive Mode	List directory in passive mode	Directory listed successfully
23	Directory Listing with Active Mode	List directory in active mode	Directory listed successfully
24	Directory Listing with Timeout	Simulate timeout during listing	Timeout error shown
25	Directory Listing with Firewall	List directory with firewall enabled	Listing may succeed or fail
26	Directory Listing with Proxy	List directory using proxy	Directory listed successfully
27	Directory Listing with VPN	List directory over VPN	Directory listed successfully
28	Directory Listing with FTPS	List directory over FTPS	Directory listed securely
29	Directory Listing with SFTP	List directory over SFTP	Directory listed securely
30	Directory Listing with Logging Enabled	Enable logging during listing	Logs show directory access
31	Directory Listing with Hidden Files	List directory with hidden files	Hidden files shown if allowed
32	Directory Listing with Filters	List files with specific extension	Only matching files shown
33	Directory Listing with Sorting	List files sorted by name/date	Files sorted as expected
34	Directory Listing with Pagination	List large directory with pagination	Files shown in pages
35	Directory Listing with Symbolic Links	List directory with symlinks	Symlinks displayed correctly
36	Directory Listing with Unicode Names	List directory with Unicode names	Names displayed correctly
37	Directory Listing with Corrupted Entry	List directory with corrupted entry	Error or partial listing
38	Directory Listing with Large Number of Files	List directory with 1000+ files	All files listed
39	Directory Listing with No Read Permission	List directory without read access	Permission denied
40	Directory Listing After Server Restart	List directory after FTP server restart	Directory listed successfully
41	Directory Listing After Session Timeout	List directory after session timeout	Re-authentication required
42	Directory Listing with Invalid Path	Use invalid path for listing	Error message shown
43	Directory Listing with Relative Path	Use relative path for listing	Directory listed successfully
44	Directory Listing with Absolute Path	Use absolute path for listing	Directory listed successfully
45	Directory Listing with Case Sensitivity	Use wrong case in directory name	Error or directory listed
46	Directory Listing with Concurrent Users	Multiple users list same directory	All users see consistent results
47	Directory Listing with File Lock	List directory with locked files	Files listed, lock status ignored
48	Directory Listing with Symbolic Path	Use symbolic path (e.g., . or ..)	Correct directory listed
49	Directory Listing with Invalid Characters	Use invalid characters in path	Error message shown
50	Directory Listing with Server Load	List directory under high server load	Listing may be delayed

FTP Feature : File Management

File Management - Testcases

S.No	Test Case	Description	Expected Result
1	Upload File	Upload a file to the server	File uploaded successfully
2	Download File	Download a file from the server	File downloaded successfully
3	Delete File	Delete a file from the server	File deleted successfully
4	Rename File	Rename a file on the server	File renamed successfully
5	Move File	Move a file to another directory	File moved successfully
6	Copy File	Copy a file to another directory	File copied successfully
7	Overwrite File	Upload a file with the same name	File overwritten or prompt shown
8	Upload File with Special Characters	Upload file with special characters in name	File uploaded successfully
9	Upload File with Long Name	Upload file with name >255 characters	Error or file uploaded
10	Upload File with No Extension	Upload file without extension	File uploaded successfully
11	Upload Hidden File	Upload a hidden file (e.g., .env)	File uploaded successfully
12	Download Hidden File	Download a hidden file	File downloaded successfully
13	Delete Hidden File	Delete a hidden file	File deleted successfully
14	Rename Hidden File	Rename a hidden file	File renamed successfully
15	Upload Binary File	Upload a binary file (e.g., .exe)	File uploaded without corruption
16	Upload Text File	Upload a plain text file	File uploaded successfully
17	Upload Large File	Upload a file >1GB	File uploaded successfully
18	Download Large File	Download a file >1GB	File downloaded successfully
19	Delete Non-existent File	Attempt to delete a file that doesnt exist	Error message shown
20	Rename Non-existent File	Attempt to rename a file that doesnt exist	Error message shown
21	Move Non-existent File	Attempt to move a file that doesnt exist	Error message shown
22	Copy Non-existent File	Attempt to copy a file that doesnt exist	Error message shown
23	File Permission Denied	Try to modify a file without permission	Permission denied error
24	File Lock Handling	Try to delete a locked file	Error or file deleted
25	File Timestamp Update	Check timestamp after file upload	Timestamp updated correctly
26	File Size Verification	Verify file size after upload	Size matches original
27	File Integrity Check	Verify checksum after upload/download	Checksums match
28	Upload with Timeout	Simulate timeout during upload	Upload fails with timeout error
29	Download with Timeout	Simulate timeout during download	Download fails with timeout error
30	Cancel Upload	Cancel an ongoing upload	Upload stops immediately
31	Cancel Download	Cancel an ongoing download	Download stops immediately
32	Resume Upload	Resume interrupted upload	Upload resumes from last point
33	Resume Download	Resume interrupted download	Download resumes from last point
34	Upload with Passive Mode	Upload file using passive mode	File uploaded successfully
35	Upload with Active Mode	Upload file using active mode	File uploaded successfully
36	File Listing	List all files in a directory	Files listed successfully
37	File Listing with Filter	List files with specific extension	Filtered files listed
38	File Listing with Sorting	List files sorted by name/date	Files sorted correctly
39	File Listing with Pagination	List large number of files	Files shown in pages
40	File Listing with Hidden Files	Include hidden files in listing	Hidden files shown
41	File Listing with No Permission	List files in restricted directory	Permission denied
42	File Listing with Corrupted Entry	List directory with corrupted file	Error or partial listing
43	File Listing After Server Restart	List files after FTP server restart	Files listed successfully
44	File Listing After Session Timeout	List files after session timeout	Re-authentication required
45	File Listing with Invalid Path	Use invalid path for listing	Error message shown
46	File Listing with Relative Path	Use relative path for listing	Files listed successfully
47	File Listing with Absolute Path	Use absolute path for listing	Files listed successfully
48	File Listing with Symbolic Links	List directory with symlinks	Symlinks displayed correctly
49	File Listing with Unicode Names	List files with Unicode names	Names displayed correctly
50	File Listing with Server Load	List files under high server load	Listing may be delayed

FTP Feature : Modes of Transfer

Modes of Transfer - Testcases

S.No	Test Case	Description	Expected Result
1	Connect in Active Mode	Establish FTP connection in active mode	Connection successful
2	Connect in Passive Mode	Establish FTP connection in passive mode	Connection successful
3	Upload File in Active Mode	Upload a file using active mode	File uploaded successfully
4	Upload File in Passive Mode	Upload a file using passive mode	File uploaded successfully
5	Download File in Active Mode	Download a file using active mode	File downloaded successfully
6	Download File in Passive Mode	Download a file using passive mode	File downloaded successfully
7	Switch from Active to Passive Mode	Change mode during session	Mode switched successfully
8	Switch from Passive to Active Mode	Change mode during session	Mode switched successfully
9	Upload in ASCII Mode	Upload a text file in ASCII mode	File uploaded with correct formatting
10	Upload in Binary Mode	Upload a binary file in binary mode	File uploaded without corruption
11	Download in ASCII Mode	Download a text file in ASCII mode	File downloaded with correct formatting
12	Download in Binary Mode	Download a binary file in binary mode	File downloaded without corruption
13	Upload Binary File in ASCII Mode	Upload binary file in ASCII mode	File corrupted or error shown
14	Upload Text File in Binary Mode	Upload text file in binary mode	File uploaded successfully
15	Download Binary File in ASCII Mode	Download binary file in ASCII mode	File corrupted or error shown
16	Download Text File in Binary Mode	Download text file in binary mode	File downloaded successfully
17	Upload Large File in Passive Mode	Upload large file using passive mode	File uploaded successfully
18	Upload Large File in Active Mode	Upload large file using active mode	File uploaded successfully
19	Download Large File in Passive Mode	Download large file using passive mode	File downloaded successfully
20	Download Large File in Active Mode	Download large file using active mode	File downloaded successfully
21	Passive Mode Behind NAT	Use passive mode behind NAT firewall	Transfer successful
22	Active Mode Behind NAT	Use active mode behind NAT firewall	Transfer fails or requires port forwarding
23	ASCII Mode Line Ending Conversion	Check line endings after ASCII transfer	Line endings converted correctly
24	Binary Mode Line Ending Preservation	Check line endings after binary transfer	Line endings preserved
25	Passive Mode with Firewall Enabled	Transfer file in passive mode with firewall	Transfer successful
26	Active Mode with Firewall Enabled	Transfer file in active mode with firewall	Transfer may fail
27	ASCII Mode with Unicode File	Transfer Unicode text file in ASCII mode	File may be corrupted
28	Binary Mode with Unicode File	Transfer Unicode file in binary mode	File transferred correctly
29	ASCII Mode with Special Characters	Transfer file with special characters	Characters may be altered
30	Binary Mode with Special Characters	Transfer file with special characters	Characters preserved
31	ASCII Mode with Large Text File	Transfer large text file in ASCII mode	File transferred successfully
32	Binary Mode with Executable File	Transfer .exe file in binary mode	File transferred without corruption
33	ASCII Mode with HTML File	Transfer HTML file in ASCII mode	File transferred correctly
34	Binary Mode with Image File	Transfer image file in binary mode	Image transferred without corruption
35	ASCII Mode with CSV File	Transfer CSV file in ASCII mode	File transferred correctly
36	Binary Mode with ZIP File	Transfer ZIP file in binary mode	File transferred without corruption
37	Passive Mode with Multiple Files	Transfer multiple files in passive mode	All files transferred successfully
38	Active Mode with Multiple Files	Transfer multiple files in active mode	All files transferred successfully
39	ASCII Mode with File Rename	Rename file during ASCII transfer	File renamed and transferred
40	Binary Mode with File Rename	Rename file during binary transfer	File renamed and transferred
41	Passive Mode with Resume Support	Resume interrupted transfer in passive mode	Transfer resumes successfully
42	Active Mode with Resume Support	Resume interrupted transfer in active mode	Transfer resumes successfully
43	ASCII Mode with Resume Support	Resume ASCII transfer	Transfer resumes successfully
44	Binary Mode with Resume Support	Resume binary transfer	Transfer resumes successfully
45	Passive Mode with Proxy	Use passive mode through proxy	Transfer successful
46	Active Mode with Proxy	Use active mode through proxy	Transfer may fail
47	ASCII Mode with Logging Enabled	Enable logging during ASCII transfer	Logs show correct data
48	Binary Mode with Logging Enabled	Enable logging during binary transfer	Logs show correct data
49	Passive Mode with High Latency	Transfer file in passive mode with delay	Transfer completes slowly
50	Active Mode with High Latency	Transfer file in active mode with delay	Transfer completes slowly or fails

FTP Feature : Transfer Types

Transfer Types - Testcases

S.No	Test Case	Description	Expected Result
1	Set Transfer Type to ASCII	Set transfer type to ASCII	Transfer type set successfully
2	Set Transfer Type to Binary	Set transfer type to Binary	Transfer type set successfully
3	Set Transfer Type to EBCDIC	Set transfer type to EBCDIC	Transfer type set successfully
4	Upload Text File in ASCII Mode	Upload .txt file in ASCII mode	File uploaded with correct formatting
5	Upload Binary File in Binary Mode	Upload .exe file in binary mode	File uploaded without corruption
6	Upload Text File in Binary Mode	Upload .txt file in binary mode	File uploaded successfully
7	Upload Binary File in ASCII Mode	Upload .exe file in ASCII mode	File corrupted or error shown
8	Download Text File in ASCII Mode	Download .txt file in ASCII mode	File downloaded with correct formatting
9	Download Binary File in Binary Mode	Download .zip file in binary mode	File downloaded without corruption
10	Download Binary File in ASCII Mode	Download .zip file in ASCII mode	File corrupted or error shown
11	Download Text File in Binary Mode	Download .txt file in binary mode	File downloaded successfully
12	Upload File in EBCDIC Mode	Upload file using EBCDIC encoding	File uploaded with EBCDIC format
13	Download File in EBCDIC Mode	Download file using EBCDIC encoding	File downloaded with EBCDIC format
14	Switch from ASCII to Binary	Change transfer type mid-session	Transfer type switched successfully
15	Switch from Binary to ASCII	Change transfer type mid-session	Transfer type switched successfully
16	Switch from ASCII to EBCDIC	Change transfer type mid-session	Transfer type switched successfully
17	Upload HTML File in ASCII Mode	Upload .html file in ASCII mode	File uploaded with correct formatting
18	Upload Image File in Binary Mode	Upload .jpg file in binary mode	File uploaded without corruption
19	Upload CSV File in ASCII Mode	Upload .csv file in ASCII mode	File uploaded with correct formatting
20	Upload Executable in Binary Mode	Upload .exe file in binary mode	File uploaded successfully
21	Upload PDF in Binary Mode	Upload .pdf file in binary mode	File uploaded successfully
22	Upload Unicode Text in ASCII Mode	Upload UTF-8 text in ASCII mode	File may be corrupted
23	Upload Unicode Text in Binary Mode	Upload UTF-8 text in binary mode	File uploaded successfully
24	Upload File with Special Characters in ASCII	Upload file with special characters	Characters may be altered
25	Upload File with Special Characters in Binary	Upload file with special characters	Characters preserved
26	Upload File with Line Breaks in ASCII	Upload file with different line endings	Line endings converted
27	Upload File with Line Breaks in Binary	Upload file with different line endings	Line endings preserved
28	Upload File with Tabs in ASCII	Upload file with tab characters	Tabs preserved or converted
29	Upload File with Tabs in Binary	Upload file with tab characters	Tabs preserved
30	Upload File with Control Characters in ASCII	Upload file with control characters	Characters may be altered
31	Upload File with Control Characters in Binary	Upload file with control characters	Characters preserved
32	Upload File with Mixed Content in ASCII	Upload file with text and binary data	File corrupted
33	Upload File with Mixed Content in Binary	Upload file with text and binary data	File uploaded successfully
34	Upload File with BOM in ASCII	Upload file with Byte Order Mark	BOM may be altered
35	Upload File with BOM in Binary	Upload file with Byte Order Mark	BOM preserved
36	Upload File with Encoding Errors in ASCII	Upload file with invalid characters	Errors may occur
37	Upload File with Encoding Errors in Binary	Upload file with invalid characters	File uploaded successfully
38	Upload File with Compression in Binary	Upload compressed file	File uploaded successfully
39	Upload File with Compression in ASCII	Upload compressed file	File corrupted
40	Upload File with Encryption in Binary	Upload encrypted file	File uploaded successfully
41	Upload File with Encryption in ASCII	Upload encrypted file	File corrupted
42	Upload File with Metadata in Binary	Upload file with metadata	Metadata preserved
43	Upload File with Metadata in ASCII	Upload file with metadata	Metadata may be lost
44	Upload File with BOM in EBCDIC	Upload file with BOM in EBCDIC mode	BOM may be altered
45	Upload File with Unicode in EBCDIC	Upload UTF-8 file in EBCDIC mode	File may be corrupted
46	Upload File with ASCII in EBCDIC	Upload ASCII file in EBCDIC mode	File converted to EBCDIC
47	Upload File with Binary in EBCDIC	Upload binary file in EBCDIC mode	File corrupted
48	Upload File with EBCDIC in Binary	Upload EBCDIC file in binary mode	File preserved
49	Upload File with EBCDIC in ASCII	Upload EBCDIC file in ASCII mode	File corrupted
50	Upload File with EBCDIC in EBCDIC	Upload EBCDIC file in EBCDIC mode	File uploaded successfully

FTP Feature : Multiple Platforms

Multiple Platforms - Testcases

S.No	Test Case	Description	Expected Result
1	Connect from Windows Client	Connect to FTP server from Windows	Connection successful
2	Connect from Linux Client	Connect to FTP server from Linux	Connection successful
3	Connect from macOS Client	Connect to FTP server from macOS	Connection successful
4	Connect from Android App	Connect using FTP client on Android	Connection successful
5	Connect from iOS App	Connect using FTP client on iOS	Connection successful
6	Connect from Embedded Device	Connect from an IoT/embedded system	Connection successful
7	Upload File from Windows	Upload file from Windows system	File uploaded successfully
8	Upload File from Linux	Upload file from Linux system	File uploaded successfully
9	Upload File from macOS	Upload file from macOS system	File uploaded successfully
10	Download File to Windows	Download file to Windows system	File downloaded successfully
11	Download File to Linux	Download file to Linux system	File downloaded successfully
12	Download File to macOS	Download file to macOS system	File downloaded successfully
13	Upload File with Windows Line Endings	Upload file with CRLF endings	Line endings preserved or converted
14	Upload File with Unix Line Endings	Upload file with LF endings	Line endings preserved or converted
15	Upload File with macOS Line Endings	Upload file with CR endings	Line endings preserved or converted
16	File Permission Handling on Linux	Upload file and check permissions	Permissions set correctly
17	File Permission Handling on Windows	Upload file and check access	File accessible
18	File Permission Handling on macOS	Upload file and check access	File accessible
19	Directory Listing on Windows	List directory contents	Files listed correctly
20	Directory Listing on Linux	List directory contents	Files listed correctly
21	Directory Listing on macOS	List directory contents	Files listed correctly
22	Rename File on Windows	Rename file from Windows client	File renamed successfully
23	Rename File on Linux	Rename file from Linux client	File renamed successfully
24	Rename File on macOS	Rename file from macOS client	File renamed successfully
25	Delete File on Windows	Delete file from Windows client	File deleted successfully
26	Delete File on Linux	Delete file from Linux client	File deleted successfully
27	Delete File on macOS	Delete file from macOS client	File deleted successfully
28	Use Passive Mode on Windows	Transfer file in passive mode	Transfer successful
29	Use Passive Mode on Linux	Transfer file in passive mode	Transfer successful
30	Use Passive Mode on macOS	Transfer file in passive mode	Transfer successful
31	Use Active Mode on Windows	Transfer file in active mode	Transfer successful
32	Use Active Mode on Linux	Transfer file in active mode	Transfer successful
33	Use Active Mode on macOS	Transfer file in active mode	Transfer successful
34	Connect via CLI on Linux	Use command-line FTP client	Connection successful
35	Connect via GUI on Windows	Use GUI FTP client	Connection successful
36	Connect via Terminal on macOS	Use terminal FTP client	Connection successful
37	Upload Unicode File from Windows	Upload file with Unicode name	File uploaded successfully
38	Upload Unicode File from Linux	Upload file with Unicode name	File uploaded successfully
39	Upload Unicode File from macOS	Upload file with Unicode name	File uploaded successfully
40	Upload File from Mobile FTP App	Upload file from Android/iOS	File uploaded successfully
41	Download File to Mobile FTP App	Download file to Android/iOS	File downloaded successfully
42	Upload File from Web-based FTP Client	Use browser-based FTP client	File uploaded successfully
43	Download File to Web-based FTP Client	Use browser-based FTP client	File downloaded successfully
44	Upload File from Virtual Machine	Upload file from VM (e.g., VMware)	File uploaded successfully
45	Download File to Virtual Machine	Download file to VM	File downloaded successfully
46	Upload File from Docker Container	Upload file from containerized app	File uploaded successfully
47	Download File to Docker Container	Download file to container	File downloaded successfully
48	Upload File from Cloud Platform	Upload file from cloud VM (e.g., AWS EC2)	File uploaded successfully
49	Download File to Cloud Platform	Download file to cloud VM	File downloaded successfully
50	Cross-Platform Compatibility	Upload from one OS, download on another	File integrity maintained

FTP Feature : Control & Data Channels

Control & Data Channels - Testcases

S.No	Test Case	Description	Expected Result
1	Establish Control Channel	Connect to FTP server	Control channel established
2	Send Command Over Control Channel	Send USER command	Server responds appropriately
3	Send Invalid Command	Send malformed command	Server returns error
4	Open Data Channel for File Transfer	Initiate file transfer	Data channel opens successfully
5	Close Data Channel After Transfer	Complete file transfer	Data channel closes properly
6	Keep Control Channel Alive During Transfer	Transfer file	Control channel remains active
7	Send Command During Data Transfer	Send command while transferring	Command queued or rejected
8	Reuse Control Channel for Multiple Transfers	Transfer multiple files	Control channel reused successfully
9	Control Channel Timeout	Leave control channel idle	Session times out
10	Data Channel Timeout	Leave data channel idle	Transfer fails with timeout
11	Control Channel Encryption (FTPS)	Use FTPS for control channel	Encrypted control channel established
12	Data Channel Encryption (FTPS)	Use FTPS for data channel	Encrypted data channel established
13	Control Channel on Port 21	Connect using default port	Connection successful
14	Data Channel on Dynamic Port	Transfer file	Data channel uses dynamic port
15	Control Channel Disconnection	Disconnect control channel	Session terminated
16	Data Channel Disconnection	Disconnect data channel mid-transfer	Transfer fails
17	Passive Mode Data Channel	Use passive mode	Data channel initiated by client
18	Active Mode Data Channel	Use active mode	Data channel initiated by server
19	Control Channel with NAT	Connect through NAT	Control channel established
20	Data Channel with NAT	Transfer through NAT	Data channel may require port forwarding
21	Control Channel with Firewall	Connect with firewall enabled	Control channel may be blocked
22	Data Channel with Firewall	Transfer with firewall enabled	Data channel may be blocked
23	Control Channel Logging	Enable logging	Commands logged correctly
24	Data Channel Logging	Enable logging	Transfer details logged
25	Control Channel with Proxy	Connect via proxy	Control channel established
26	Data Channel with Proxy	Transfer via proxy	Data channel established
27	Control Channel with VPN	Connect via VPN	Control channel established
28	Data Channel with VPN	Transfer via VPN	Data channel established
29	Control Channel with TLS	Use TLS encryption	Secure control channel
30	Data Channel with TLS	Use TLS encryption	Secure data channel
31	Control Channel with Multiple Clients	Multiple clients connect	All control channels managed independently
32	Data Channel with Multiple Transfers	Multiple transfers initiated	Data channels handled correctly
33	Control Channel with Unicode Commands	Send commands with Unicode	Server handles correctly
34	Data Channel with Unicode Filenames	Transfer files with Unicode names	Files transferred correctly
35	Control Channel with Invalid Encoding	Send command with wrong encoding	Server returns error
36	Data Channel with Invalid Encoding	Transfer file with wrong encoding	File may be corrupted
37	Control Channel with Compression	Compress control channel	Commands transmitted correctly
38	Data Channel with Compression	Compress data channel	File transferred correctly
39	Control Channel with Session Persistence	Maintain session across reconnect	Session resumes or re-authenticates
40	Data Channel with Resume Support	Resume interrupted transfer	Transfer resumes successfully
41	Control Channel with Command Queue	Queue multiple commands	Commands executed in order
42	Data Channel with Parallel Transfers	Transfer multiple files simultaneously	All transfers succeed
43	Control Channel with Invalid Port	Use incorrect port	Connection fails
44	Data Channel with Port Conflict	Use port already in use	Transfer fails
45	Control Channel with Server Restart	Server restarts mid-session	Control channel disconnected
46	Data Channel with Server Restart	Server restarts mid-transfer	Transfer interrupted
47	Control Channel with Load Balancer	Connect through load balancer	Control channel routed correctly
48	Data Channel with Load Balancer	Transfer through load balancer	Data channel routed correctly
49	Control Channel with IPv6	Connect using IPv6	Control channel established
50	Data Channel with IPv6	Transfer using IPv6	Data channel established

FTP Feature : Logging & Auditing

Logging & Auditing - Testcases

S.No	Test Case	Description	Expected Result
1	Enable Logging	Turn on logging on FTP server	Logging enabled successfully
2	Disable Logging	Turn off logging	Logging disabled successfully
3	Log User Login	User logs in to FTP server	Login event recorded in log
4	Log User Logout	User logs out from FTP server	Logout event recorded in log
5	Log File Upload	Upload a file to server	Upload event recorded
6	Log File Download	Download a file from server	Download event recorded
7	Log File Deletion	Delete a file from server	Deletion event recorded
8	Log File Rename	Rename a file on server	Rename event recorded
9	Log Directory Creation	Create a new directory	Directory creation logged
10	Log Directory Deletion	Delete a directory	Directory deletion logged
11	Log Failed Login Attempt	Attempt login with wrong credentials	Failed login recorded
12	Log Successful Login	Login with correct credentials	Successful login recorded
13	Log Session Timeout	Session times out due to inactivity	Timeout event logged
14	Log Session Termination	User disconnects manually	Disconnection logged
15	Log Passive Mode Transfer	Transfer file in passive mode	Transfer logged with mode info
16	Log Active Mode Transfer	Transfer file in active mode	Transfer logged with mode info
17	Log ASCII Transfer	Transfer file in ASCII mode	Transfer type logged
18	Log Binary Transfer	Transfer file in binary mode	Transfer type logged
19	Log EBCDIC Transfer	Transfer file in EBCDIC mode	Transfer type logged
20	Log IP Address	Record client IP address	IP logged with session info
21	Log Port Number	Record port used for connection	Port number logged
22	Log Transfer Size	Record size of transferred file	File size logged
23	Log Transfer Duration	Record time taken for transfer	Duration logged
24	Log Transfer Status	Record success/failure of transfer	Status logged
25	Log Command Execution	Record FTP commands issued	Commands logged
26	Log Invalid Commands	Record invalid or rejected commands	Errors logged
27	Log Permission Denied	Attempt unauthorized action	Permission error logged
28	Log File Overwrite	Overwrite existing file	Overwrite event logged
29	Log File Resume	Resume interrupted transfer	Resume event logged
30	Log Concurrent Sessions	Multiple sessions from same user	All sessions logged
31	Log Anonymous Login	Login using anonymous credentials	Anonymous access logged
32	Log Encrypted Session	Use FTPS/SFTP	Encryption method logged
33	Log Firewall Block	Blocked connection attempt	Block event logged
34	Log Proxy Access	Access via proxy	Proxy details logged
35	Log VPN Access	Access via VPN	VPN IP logged
36	Log File Integrity Check	Verify checksum after transfer	Checksum result logged
37	Log File Metadata	Record file name, type, size	Metadata logged
38	Log Directory Navigation	Change working directory	Navigation logged
39	Log Server Restart	Restart FTP server	Restart event logged
40	Log Configuration Change	Change FTP settings	Change logged
41	Log User Creation	Create new FTP user	User creation logged
42	Log User Deletion	Delete FTP user	Deletion logged
43	Log User Role Change	Modify user permissions	Role change logged
44	Log Audit Trail Export	Export audit logs	Export event logged
45	Log Log File Rotation	Rotate log files	Rotation event logged
46	Log Log File Archival	Archive old logs	Archival event logged
47	Log Log File Deletion	Delete old logs	Deletion event logged
48	Log Access to Logs	Access or read log files	Access event logged
49	Log Tampering Attempt	Attempt to modify logs	Tampering attempt logged
50	Log Retention Policy	Apply log retention rules	Policy enforcement logged

Reference links

• Reference links