Can someone please tell me how to restrict SSH access only to certain IP ranges (e.g. local network) and not the whole Internet? I guess this has to be done via firewall.
/etc/hosts.allow /etc/hosts.deny Access controls that should be enforced by tcp-wrappers are defined here. Further details are described in hosts_access(5).
https://debian-administration.org/article/87/Keeping_SSH_access_secure offers these examples:
# /etc/hosts.allow sshd: 220.127.116.11/255.255.255.0 sshd: 192.168.0.0/255.255.255.0 # /etc/hosts.deny sshd: ALL
The TCP wrapper program in Mac OS X is: