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My current settings are here:

I understand the HTTP and the SSH lines but do I need the first three lines for icmp, tcp and udp? I must have set this up a couple years ago but I am looking to get it right this time and use EC2 properly.

Any help is appreciated - thanks!

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up vote 1 down vote accepted

The first three lines allows to enable the communications on all ports between EC2 instances which have started behind your default Security Group.

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So, I should keep them there if I want someday to have a web/app server on a separate instance than my DB right? – drhyde Mar 13 '11 at 20:36
Yes, otherwise your web app server can not connect with your DB. – fafanoulele Mar 14 '11 at 9:41
Got it, thanks. I am unable to ping the EC2 instance though it serves up HTTP and I can ssh to it just fine. What's the best way to enable ping - change the icmp protocol's source to - or do I do that for the tcp protocol? – drhyde Mar 14 '11 at 17:54
Yes, for enable ping, change or add the icmp protocol's source to Source to allows to authorize ping from all IP. – fafanoulele Mar 15 '11 at 10:59

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