it's quite usual, that the DB servers are protected from access from the internet, and if your hadoop cluster is not in the company network, it is considered as being internet, so you security team will not allow access.
You can discuss with your networks security team, if a VPN tunnel from your hadoop cluster to the sql server is possible, but in most cases, network security will require in that cases to apply all internal security standards on your hadoop cluster as well, as otherwise they are not considered as trustworthy.
Another option is, if a SSH connection is allowed from the ms SQL server to your hadoop cluster, in that case you could tunnel the port 1433 as well to use it from hadoop.
A common solution to this situation is also to migrate the hadoop cluster from a cloud location to a on premise installation.