I'm not really seeing a lot in the results you uploaded.  Here are a few suggestions to see if we can make some progress.

1. Reboot all VMs (including your prime client and client0) and try again.
2. If you are still seeing an issue: Although you said you only have one NIC on your primeclient I see two IP addresses.  You may want to review your networking configuration.  Additionally, it would help if you went ahead and posted your Standby0's /etc/hosts file and it's /usr/local/staf/bin/STAF.cfg file for us to review.
3. You could also add the alias "primeclient" to the primeclient's /etc/hosts file (with IP 127.0.0.1)