Worker Troubleshooting

Hi all

I'm having issues setting up a worker on a site separate to the super. I'm not sure if I'm attempting to troubleshooting connectivity issues or if something else is occurring so I hoped to get some assistance or a troubleshooting worker connectivity guide before I escalate this. 

The issue I'm seeing is as follows:

Add node in super
Super connects to worker on service 7900 and attempts to register
Comms both ways on my tcpdump 
Worker attempts to connect to my NFS server (seems successful there) 
Super advises that the add operation for the worker failed

According to the firewall teams we're not seeing anything dropped that could be causing the issue. We are currently using 6.3.3 of the software. We have a collector in the same subnet that isn't having comms issues but still not ruling it out (collector is only 443 traffic so not nearly as complex a setup). 

Please advise?

Thanks!