# Using tuna in a corporate network

Most often there should be no problems with this, as corporate firewalls allow outgoing connections, however there may be restrictions on connection ports that may interfere with tuna operation.

If you encounter errors when creating a tunnel, run the `tuna diagnose` command to get diagnostic information. The report will help you better understand where exactly the problem is.

```shell
Please wait, testing connectivity...

TLS connectivity:
  Google.com: ok [1.46189625s]
  Yandex.ru: ok [1.246520375s]
  tuna API: ok [1.484186875s]
  tuna NL location: ok [739.467083ms]
  tuna RU location: ok [597.777167ms]
TCP connectivity:
  tuna NL location: ok [75.757708ms]
  tuna RU location: ok [34.079541ms]

```

As a rule, tuna uses port `443` to connect to nodes when creating a tunnel. If the `TCP connectivity` checks fail, contact your network administrators to resolve the issue.