TCP Wrappers in Linux/CentOS/Redhat/Fedora
yum info tcp_wrappers
yum install tcp_wrappers-devel.x86_64
506 reboot
507 ifdown ens33
508 ifup ens33
509 yum install tcp_wrappers-devel.x86_64
510 yum -y install tcp_wrappers-devel.x86_64
511 ls /var/ftp/pub/Packages/
512 ls /etc/yum.repos.d/local.repo
513 vim /etc/yum.repos.d/local.repo
514 systemctl status vsftpd
515 systemctl start vsftpd
516 systemctl enable vsftpd
517 yum -y install tcp_wrappers-devel.x86_64
518 cat /etc/hosts.allow
519 cat /etc/hosts.deny
520 two config files as above. hosts.allow will be consulted first and then hosts.deny is consulted
521 the format of the file content: service: user@source pc
522 service examples: All, All Except, sshd, vsftpd, sshd. multiple services can be given in one line with commas
523 user@source pc examples can be: All, just an IP, 192.168.1.1 Local, subnet: 192.168.0.0/24, network address with except host like: 192.168.0 except 192.168.0.25. multiple host can be given – comma separated. user1@192.168.1.1
524 the above content will serve the purpose of the file. if the content is found on the allow file – that services and user and pc will be allowed. if the content is written in the .deny file – corresponding user, service, pc will be denied
525 exit
526 history