I have created kubernetes cluster using kops and kubectl in main EC2 instance and master-child node created automatically.

kops create cluster \
--state=${KOPS_STATE_STORE} \
--node-count=2 \
--master-size=t2.medium \
--node-size=t2.medium \
--zones=ap-south-1a,ap-south-1b \
--name=${KOPS_CLUSTER_NAME} \
--dns private \
--master-count 1

I am able to connect kops ec2 instance(main) from git bash,or directly. But I am not able to open master instance either way.

 ssh -i key1.pem ec2-user@kops-ip  #working for kops 

While connecting to master node its giving:

There was a problem setting up the instance connection
Log in failed. If this instance has just started up, try again in a minute or two.

My question is:

1.How to open master ec2 instance?

2.Do I need to install kubernetes dashboard in master or in kops instance(currently having)?

AWS Instances:

kops(ec2-user)
master-ap-south-1a.masters.a.com
nodes.a.com 
nodes.a.com