In some network environments, firewalls may be blocking the communication with Splashtop servers and thereby preventing Splashtop from working properly.
Testing Network Accessibility
You can determine whether this is the case by running the Splashtop network check tool from within those network environments. Just browse to www.splashtop.com/check using a device that's on the network you want to test.
Allowing Communication with Splashtop Servers
If communication is blocked, please enable your firewalls to allow communication in both directions with these domains:
- *.api.splashtop.com (* represents wildcard)
- *.relay.splashtop.com (* represents wildcard)
- sn.splashtop.com (for endpoints auto-update)
Port 443 needs to be open, including non-ssl traffic
There are numerous Splashtop servers across several regions, but they are all covered under the above wildcard domains. This is the easiest way to allow access through firewalls.
If both devices are on the same network, communications are point-to-point via TCP ports 6783-6785 (default setting). For tight firewalls, you may need to allow these TCP ports internally (not externally).
IP Addresses of Splashtop Servers
Splashtop servers reside in datacenters hosted by Amazon & Google Cloud Platform. The servers' IP addresses are dynamically allocated and change over time. Therefore, it is not really practical to configure your firewall exceptions using IP addresses. The list of IP addresses is long, and they may change from time-to-time. The best way is to configure your firewall exceptions using the wildcard domains above.
If you do need the IP addresses of the Splashtop API servers, you can use the following commands to look up the current IP addresses:
- nslookup ca-st2.api.splashtop.com
- nslookup oregon-st2.api.splashtop.com
- nslookup ca-st2-relay.api.splashtop.com
- nslookup oregon-st2-relay.api.splashtop.com
- nslookup cn-st2-relay.api.splashtop.com
If you need the IP addresses of the Splashtop relay servers, please contact our support team.