how to set up an ftp server behind huawei smartAX MT880?

You need to allow forward port 21, in the Virtual Server list of your modem.

and how is that supposed to be?

Access your Router admin page, by typing 192.168.1.1 in your browser, use admin/admin as username/password, and then click Virtual Servers from the left pane.

Edit the Virtual FTP on the list, if present or add a new one for FTP. Enter your ip address, and port no as 21.

i already have port TCP 21/21 on the list and it is scheduled for "always"...
so no i cant figure out what to do....
i just cant get it!
if i forgot to mention........ there is a hub between the computr and the modem....

The firewall is also working fine.....

Well, you'll see it on the list, It wont be checked. Click on edit (That notepad icon at the extreme right) and chanhe the status to "enabled"

and do i fill my computer's network ip (192.168.1.2) in the private ip field?

PS: i get this error "Error adding NAT reserved mapping pool def01"

mario_pant said:

and do i fill my computer's network ip (192.168.1.2) in the private ip field?

Click to expand...

YES

mario_pant said:

PS: i get this error "Error adding NAT reserved mapping pool def01"

Click to expand...

That usually mean the created port forward rules by UPnP were conflicted with the existing port forward rules which were created manually. Just ignore the warning