Apparently SSH outbound connections are not allowed in ESX by default, or are at least not allowed anymore by default. I say this as I have never had to allow ssh outbound before. Anyway, I ran into this today when attempting to scp a file off of one of my esx servers.
To allow check if outbound ssh connections are allowed run the following command to see if sshClient is blocked.
[root]# esxcfg-firewall -q sshClient
Service sshClient is blocked.
Run the following command to allow sshClient traffic.
[root]#esxcfg-firewall -e sshClient
I have previously posted how to configure the ESX firewall to allow SNMP and NTP here. Its also important to note that this the process below does not allow ssh inbound connections. That is configured by allowing the sshServer service through the firewall. Commands below.
[root]#esxcfg-firewall -e sshServer