Ssh: Could not resolve hostname

If you encounter this message while trying to ssh to the discovery or endeavour cluster you are most likely having problems with VPN.

ssh: Could not resolve hostname nodename nor servname provided, or not known

This message is letting you know that that ssh is having trouble matching the hostname or to an IP address. The first step to resolving this issue is to make sure you are connected to the USC VPN. You can read more about that process here:

Occasionally Mac users will still encounter this message despite being on VPN. In this case the issue is most likely due to your DNS cache. After connecting to VPN you can flush your cache by running the following commands:

sudo dscacheutil -flushcache 
sudo killall -HUP mDNSResponder

You should then be able to connect to the cluster. If you’re still having problems, you can open a ticket with us by sending mail to