# 切換終端機
# Ctrl + Alt + F1 ~ Ctrl + Alt + F6 (CentOS 6)
# Alt + F1 ~ Alt + F6 (CentOS 7)
# 檢查 IP
$ ip a
# CentOS 6 ip/CentOS 7 ip 互 ping
$ ping <CentOS 6 ip/CentOS 7 ip>
# CentOS 6 ip/CentOS 7 ip 互 ping
$ ping <CentOS 6 ip/CentOS 7 ip>
# ping 外網
$ ping <domain>