Troubleshooting Questions

How do I know if the FTP ALG is active?
- The ALG protocol field in the conversation should display ftp.
- There should be a valid frame count (Frm count) in the control flows.
- A valid frame count in the data flows indicates that data transfer has taken place.
What do I need to check if the FTP connection is established but data transfer does not take place?
- Most probably, the control connection is up, but the data connection is down.
- Check the conversations output to determine whether both the control and data flows are present.
How do I interpret each flow? What does each flow mean?
- FTP control flow initiator flow—flow with destination port 21
- FTP control flow responder flow—flow with source port 21
- FTP data flow initiator flow—flow with destination port 20
- FTP data flow responder flow—flow with source port 20