I've whitelisted my own domains in /etc/hosts.allow
ALL: localhost, .domain.tld
plus all of my IP adresses.
I also have about 4k lines in /etc/hosts.deny
.
Everything works but I do not understand the warning I get from time to time, because not all connections return a mismatch:
Feb 4 09:01:13 my sshd[24068]: warning: /etc/hosts.allow, line 14: host name/name mismatch: UNKNOWN-110-75-188-34.aliyun.com != my.domain.tld
Update:
My IP mapps to domain.tld, and domain.tld maps to my IP.
*.aliyun.com is some BruteForcing machine, attacking my server.