[ALUG] sshd configuration problem

[Chris G]

By default I have sshd set up to disallow root logins, if I want to
get to root from a remote login I login as myself (one password) and
then su to root (another password).

However I want to allow root login from one other system on the local
LAN.  To this end I added the following to the end of sshd_config:-

    PasswordAuthentication no
    AllowUsers root at 192.168.1.7   

However this, of course, prevents anyone logging in from anywhere
except for root at 192.168.1.7.

How can I allow any non-root user from anywhere but root only from
192.168.1.7? 

-- 
Chris Green