sellinux가 네트웤관련 서비스들의 포트들을 고정시켜뒀기 때문이므로 아래와 같이 포트를 허용하던가 selinux를 사용하지 않던가 선택을 해야함.
5.4. Allowing Access to a Port
We may want a service such as Apache to be allowed to bind and listen for incoming connections on a non-standard port. By default, the SELinux policy will only allow services access to recognized ports associated with those services. If we wanted to allow Apache to listen on tcp port 81, we can add a rule to allow that using the 'semanage' command:
# semanage port -a -t http_port_t -p tcp 81
A full list of ports that services are permitted access by SELinux can be obtained with:
# semanage port -l
예2) ssh 포트변경하려면... semanage port -l | grep ssh //(-l옵션으로 리스트 확인하여 상황에 맞게 처리) semanage port -a -t ssh_port_t -p tcp 81
