SFTP client inside router

RouterOS Beginner Basics
1

I’m unclear on what needs to be done to allow an SFTP (WinSCP) client to work from the inside computer to an external server. Standard FTP worked without doing anything.

My router log records “Auth Timeout” as the only entry, and it only did that once, despite multiple attempts.

The router is pretty much “stock” except for a L2TP server and providing local DHCP. It seems like the router should see the outgoing port 22 traffic and know where to send the returning packets.

My SFTP client log shows “Access Granted” to it’s second authentication choice, then:
Opening main session channel
Network error: Software caused connection abort
Network error: Software caused connection abort

2

Perhaps this applies??
http://forum.mikrotik.com/t/sftp-uploads-to-remote-sftp-server-solved/143724/7

3

It turns out the server had a folder permission wrong, so it let me logon but not see folders. Ended up not needing any special router settings.