I have a networking issue I'm trying to solve. I have two EC2 instances, same zone, same type.

On one of the two EC2 instances (the 'bad' instance), the download speed is really poor (200k/s), while on the other (the 'good' instance), the download speed is fine, comfortable at 30M/s +). To clarify, I'm talking about downloading files to the EC2 instance while ssh'd into the server, e.g running wget with a large file. I've tried different files, including S3 objects and a large linux ISO from elsewhere.

Running ethtool eth0 only returns 'Link detected: yes' for both.

When running ifconfig, both return the same for most part, aside from how the good instance shows no error packets yet the bad instance shows many:

UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
RX packets:168372370 errors:5075643 dropped:0 overruns:0 frame:0
TX packets:122116480 errors:0 dropped:0 overruns:0 carrier:0

Both servers are configured the same, at least were supposed to be. How can I go about diagnosing the cause for the slow download speed? Is there anything particular to EC2 instances that could cause this?

Having trouble knowing where to start. Thanks for any help!