Dell N-3048P switch setup with a management vlan and a default gateway.  Trying to copy the running or startup config, " copy run config tftp://x.x.x.x/filename" and failed.

There's connectivity between the switch and the server (verified with ping source ip from management vlan).  UDP por 69 is opened on the firewall.  I don't see tftp traffic hitting the firwall (counter 0 traffic) when I initiate tftp from the switch.