Unable to install services on my instance.


What am I doing wrong?

I could have swore I am doing it right.

[ec2-user@localhost ~]$ sudo yum install -y telnet-server

Amazon Linux 2023 repository 0.0 B/s | 0 B 00:00
Errors during downloading metadata for repository 'amazonlinux':

asked 3 months ago508 views
1 Answer


This seems to be a DNS error: your EC2 instance cannot access DNS servers to the resolve the name in questions to IP addresses.

2 possible main causes:

  • security group(s) or network ACLs barring access to DNS service (UDP 53)
  • internet access to reach the DNS servers not possible: so, either a routing table, a NAT (+ Internet) gateway missing in your VPC.

Please, check those elements!



profile pictureAWS
answered 3 months ago
  • I am not a network wizard. I have no idea how to check this or fix it.

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