当我从MacOS Sierra终端连接到我的AWS Ubuntu实例时，我会在几分钟内启动，并出现以下错误：
packet_write_wait: Connection to 52.152.221.18 port 22: Broken pipe
我使用所有默认设置设置AWS Ubuntu服务器。我已经阅读了有关获得启动问题的其他帖子 - 我相信我能搞清楚。但是，我的问题是，一旦启动，我就无法重新连接到AWS实例。以下是错误和尝试重新连接失败的ssh命令。我该如何纠正这种情况？
ubuntu@ip-171-31-50-30:~/scripts$ packet_write_wait: Connection to 52.152.221.18 port 22: Broken pipe
jk-MacBook-Pro:credentials jk$ ssh -i ubuntu-server-12-18-2016.pem ubuntu@ec2-52-152-221-18.compute-1.amazonaws.com
ssh: connect to host ec2-52-152-221-18.compute-1.amazonaws.com port 22: Operation timed out
jk-MacBook-Pro:credentials jk$ ssh -i ubuntu-server-12-18-2016.pem ubuntu@ec2-52-152-221-18.compute-1.amazonaws.com
ssh: connect to host ec2-52-152-221-18.compute-1.amazonaws.com port 22: Operation timed out
jk-MacBook-Pro:credentials jk$