If you set up two EC2 in tow AWS regions, and test latency between them, there is no any result comes out. Even though the connection is valid, but sees all of packages are dropped by some reason.
For instance: one EC2 in us-east-1, and the other in ap-southeast-1, you run command like below:

for server EC2:
./ethr -s --port 5023.
for client EC2:
./ethr -c xxxx.xxxx.xxxx.xxxx -n 16 --port 5023 -p tcp -t l

And you got nothing related to valid result, but the connection is ok.
Screen Shot 2022年05月19日 at 19 25 23

If you put two EC2 in the same region, and do the same test, and you will get the expected result..
Screen Shot 2022年05月19日 at 19 27 17

I noticed that AWS has a MTU 1500 bytes restriction for traffic over an internet gateway, so my question is does ethr latency test will send a package over the 1500 bytes size? And how can I solve this issue