Silktree updates the /etc/passwd and /etc/group files on a list of child nodes via SSH. At the lowest level, six Debian system utilities are employed: {add,del}{user,group}, {user,group}mod. The information is transferred from the head-node to the child-nodes. Several sudo-capable mini-scripts on the child nodes ensure limitations while committing the changes. End-to-end checking ensures a reliable update.