Explanation
The FTP client sent a PORT
command to the z/OS® FTP
server. The PORT command is not appropriate for the current session
because the session protocol is not IPv4. The FTP client might send
such a command to the server if the user is trying to proxy transfer
files between two servers, and the two servers are known to the client
by IP addresses of different protocol families. Even a z/OS FTP server
with both IPv4 and IPv6 interfaces will not accept a PORT command
if the client logged in to that server with an IPv6 IP address.
System action
The FTP server rejects the
PORT command. The server waits for the next FTP command.
User response
If you received this reply
while attempting a proxy transfer of data between two servers, and
the proxy transfer failed subsequent to this reply, try the strategies
listed below. If you received this reply under any other circumstance,
report the error to the system programmer.
- Log in to the FTP servers as before, but reverse the order in
which you log in to those servers. Try the proxy transfer again.
The strategy is to reverse the roles of the FTP servers from the
client's perspective so that the FTP client sends PORT or EPRT to
the other FTP server.
- Log in to each server again by specifying server IP addresses
of the same protocol family, and try the proxy transfer again.
If you know the servers only by DNS names, ask the system programmer
what the server IP addresses are. If both servers are z/OS FTP servers,
this is the only way to successfully proxy transfer files.
- If neither of the above strategies succeeds, you cannot proxy
transfer files directly between the servers. Transfer the file first
to the client, then from the client to the other server.
System programmer response
If the user
is attempting proxy transfer between two FTP servers, verify that
the user correctly attempted the strategies in the User or Operator
Response. Otherwise, report the error to the provider of the
FTP client software.