An Amazon EC2 Instance Is Unable to Connect an SMTP

question 919

Multiple Choice

An Amazon EC2 instance is unable to connect an SMTP server in a different subnet. Other instances are successfully communicating with the SMTP server, however VPC Flow Logs have been enabled on the SMTP server's network interface and show the following information: 2 223342798652 eni-abe77dab 10.1.1.200 10.100.1.10 1123 25 17 70 48252 1515534437 1515535037 REJECT OK What can be done to correct this problem?

• A) Add the instance to the security group for the SMTP server and ensure that is permitted to communicate over TCP port 25.
• B) Disable the iptables service on the SMTP server so that the instance can properly communicate over the network.
• C) Install an email client on the instance to ensure that it communicates correctly on TCP port 25 to the SMTP server.
• D) Add a rule to the security group for the instance to explicitly permit TCP port 25 outbound to any address.

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Definitions:

Point Estimate

A single value that serves as the best guess or best estimate of a population parameter based on sample data.

Point Estimate

A single value given as the best guess or estimate representing a population parameter, based on sample data.

Proportion

A part, share, or number considered in comparative relation to a whole; a statistical measure often used to describe a characteristic of a sample.

Variability

The extent to which data points in a statistical distribution or dataset differ from the average or mean value.