Amazon EC2 instance cannot resolve hostnames

Question

My free tier EC2 instance (ubuntu 11.04, created last year) is expired. I just created a new one (ubuntu 12.04), but found that the new EC2 cannot resolve any hostname. By checking /etc/resolv.conf.

The old one looks like:

domain ap-northeast-1.compute.internal
search ap-northeast-1.compute.internal
nameserver 172.16.0.23

Where the new one looks like:

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN

Is the nameserver configuration not automatically set up now? How should I configure the nameserver, through the AWS console? Do I have to use Route 53? I would rather use a free solution if it's not too complicated to set up.

That is strange, `resolve.conf` should not be empty. Did you use the stock Ubuntu 12.04 AMI or did you use a community AMI to create your instance? — David Levesque, Oct 10 '13 at 17:17
I picked the one from "quick start" list. AMI full name: Ubuntu Server 12.04.2 LTS. — Stan, Oct 10 '13 at 18:28

David Levesque · Accepted Answer · 2013-10-11T03:18:25.297

5

I was curious so I just launched an instance using AMI "Ubuntu Server 12.04.2 LTS" and I have this in resolv.conf:

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 172.16.0.23
search us-west-2.compute.internal

So maybe something went wrong when you created your instance. Try launching a new one.

Edit: Since your instance is inside a VPC, try Creating a DHCP Options Set with domain-name-servers=AmazonProvidedDNS, then assign the options set to your VPC.

edited Oct 11 '13 at 03:18

answered Oct 10 '13 at 19:01

David Levesque

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My resolv.conf is same as yours. But after rebooting the instance in the AWS console, the resolv.conf is gone. How can I get it back? – Stan Oct 10 '13 at 20:16
Is your instance inside a VPC? – David Levesque Oct 10 '13 at 20:37
Yes, it got a VPC id. – Stan Oct 11 '13 at 02:10
See my edit about VPC. – David Levesque Oct 11 '13 at 03:18

score 3 · Answer 2 · edited Feb 18 '14 at 10:09

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Here's what I appear to have observed: when I skipped the configure steps in the Create Wizard, my instance had an empty resolv.conf, but when I clicked through the steps (didn't change the defaults, just clicked through dutifully), then the resolution configuration had the nameserver in it.

edited Feb 18 '14 at 10:09

Falcon Momot

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answered Feb 16 '14 at 21:08

sameers

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score 1 · Answer 3 · answered Aug 28 '15 at 22:38

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Change the DNS options for your VPC. http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_DHCP_Options.html You can add your private DNS there, and instead of adding the AWS DNS server, the DHCP update will put the addresses you have configured.

answered Aug 28 '15 at 22:38

Victor Oliveira

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Please expand your answer to include relevant details from the link, so that when the content linked to disappears, your answer is still useful. – womble Aug 28 '15 at 23:29

Amazon EC2 instance cannot resolve hostnames

3 Answers3