Setup a New Serv-U Domain with Higher SFTP Encryption Level

Overview

How to set different encryption levels in Serv-U without affecting existing users. This will suit if a single user requires stronger SSH encryption. Strong (2048 or greater) SSH encryption has an negative effect on performance but is more secure. This does not suitable for every user.

Environment

Serv-U all versions

Steps

Create a new Serv-U Domain

If the computer running Serv-U has only one IP address, the way to setup multiple domains is to configure each listener on each domain to listen on a different port (i.e. SFTP on port:222) to prevent listener conflict.

If the sole purpose of the new domain is SFTP, then open the relevant port on the firewall and allow only SFTP traffic.

Domain1 :22 > SFTP
Domain2 :222 > SFTP

You may set Domain level Limits and Settings > Encryption settings on Domain2 which will not impact Domain1
Domain2 will have a 2048 bits key and will only be used for its own domain.