The scp program must be part of all SSH servers that want to provide SCP service, as scp functions as SCP server too. The scp program is the secure analog of the rcp command. The openssh versions of scp and sftp have a built in 1 MB buffer that severely limits performance on a WAN. While these tools work fine in a local environment, they perform poorly on a WAN.
This is useful for specifying options for which there is no separate scp command-line flag. This is similar to our basic scp command, except for this special command: -o Prox圜ommand='ssh nc 172.31.8.133 22' -o ssh_option Can be used to pass options to ssh in the format used in ssh_config (5).
