Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I created a new ec2 ubuntu instance. I can't connect to the instance, all I get is connection timed out when I try to connect. I can't ping the instance either. If I try to add new security rules in the amazon ec2 dashboard I cannot save them (the save button will not become active).

I may be using an ami that doesn't work with the free instance (from some things I have read that can be a problem) but I can't see how I am suppose to tell if that is the problem or how to find a ami that will work.

share|improve this question provides some very good information but didn't help me. I still just get connection timeout and no indication of what to try next. – curiouscat Dec 11 '10 at 19:44

The reason you cannot reach the instance is because the Firewall (controlled by the Security Groups) is not open to you. The reason you cannot save is because you need to include an IP address AND a CIDR mask. In plain english, you need to format your rules like this.

  • xx.xx.xx.xx/#

The /# is something in the range /0 to /32. /32 basically says only open to this IP, while something like /24 would say open to this IP, and anything with an IP with the same first 3 groupings. For you, if your IP was, in the security group pick your port to open and add


At the end, then click save. This will open the firewall to just your current IP, and should let you access your instance.

share|improve this answer
Thanks. Signing in to try to look into this, I see Amazon has decided to charge me $30 for the free trial I setup. I have to say I liked the idea of it but the execution has driven me away. I am much more comfortable with Linode or Slicehost they tell you what they will charge. They don't say this will be $20 and then just charge $40 to your credit card with no authorization from you. I only wanted to try since they said it was a free trial. I won't try them again for a long time unless I have a business case that screams out to use them - I'll avoid them if I can. – curiouscat Dec 21 '10 at 4:37
It sounds like the instance you turned up was not a micro instance, probably a m1.small or m1.large, which will incur costs =/ – Flashman Dec 21 '10 at 17:38

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.