物理机和虚拟机互相可以ping通，还是无法连接

CentOS、Fedora

# systemctl stop firewalld.service
# yum install openssh-server
# service sshd start

Debian

# iptables -F
# apt install openssh-server
# service sshd start

Ubuntu

# ufw disable
# apt install openssh-server
# service sshd start