ubuntu,couldn't read interfaces file - Linux

因為網路一直不通
輸入:
sudo /etc/init.d/networking restart
或是
ifup eth1
等指令

就會出現

/etc/network/interfacs:30: duplicate interface
ifdown: couldn't read interfaces file "/etc/network/interfaces"

等訊息
到/etc/network去看interface
權限也都有r讀取阿
那為甚麼他說無法讀取

還有30是什麼意思?

謝謝!

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