Mac – Unable to scp from remote to local Mac

I'd prefer to use a syntax like interactive FTP and just 'pull' files from the server to my local pwd.

Use sftp.

(Hint: If you cannot or do not want to open a new window, you can suspend the SSH connection by pressing Enter, ~, CtrlZ, transfer your files, and resume SSH with fg.)

Another possible solution might be to have some way to automatically set up my client computer as an ssh alias

There are a few ways.

• Static alias for ssh and scp – add this to your ~/.ssh/config:

  Host home
      # If you don't have a domain name, check out DynDNS...
      # ...or just use your IP address.
      Hostname homepc.somedomain.tld
  
      # If necessary, uncomment:
      #User john
      #Port 1234
  

  Use:

  scp foo home:
  

  (If you don't provide a path after :, the file will go to your home directory.)

• Use the SSH_CLIENT environment variable.

  export client=${SSH_CLIENT%% *}
  if [[ $client == *:* ]]; then
      client="[$client]"
  fi
  

  Put that in ~/.profile or ~/.bash_profile or wherever you want, then use $client when you need your own address.

  scp foo "$client:"
  

• Mix both.

  ~/.ssh/config:

  Host client
      ProxyCommand ~/bin/reverse-connect %p
  

  ~/bin/reverse-connect:

  #!/bin/sh
  if [[ $SSH_CLIENT ]]; then
      client=${SSH_CLIENT%% *}
  else
      echo "I don't know your address." >&2
      exit 1
  fi
  if [[ $client == *:* ]]; then
      client="[$client]"
  fi
  
  port=${1:-22}
  
  exec socat - "tcp:$client:$port"
  

  Use:

  scp foo client:
  

You can use SSH tunneling for this.

Using tunneling you can forward a TCP port either from your local machine to the remote machine, or from the remote machine to your local machine. I use it frequently to forward e.g. SMTP or IMAP ports from a remote machine behind a firewall to my local machine (and then access the services locally, as if they were running locally).

To forward port 22 (SSH) from you local machine to the remote machine try this:

ssh -R12345:localhost:22 yourremoteuser@remotemachine

(Note that localhost refers to the local name of the remote machine)

After running this you should be able to ssh back home using:

ssh -p12345 yourlocaluser@127.0.0.1

When using scp, you would do something like (scp has an uppercase P for port forwarding):

scp -P12345 filename 127.0.0.1:/tmp/filename

Port forwarding in the other direction (from remote to local) uses -L instead of -R.

The above commands assume that you are using a terminal ssh client. Graphical clients, like PuTTY for Windows, also support tunneling