@george1421 Edit: Misread the question.

Everything is on the same subnet. We’re on a .23 subnet. In fact all the devices I’m using for testing are plugged into the same switch.

I’ll work on getting the info you need.

Much thanks, George and others for the help. As well as saving my company thousands of dollars! :)

@george1421 I tested that earlier. It works.

Okay, I managed to upload a PCAP from Wireshark:

Wireshark Capture

After much frustration, I set up another Fog installation on Ubuntu that is working much better. I still get a “TFTP open timeout” but at least I can transfer TFTP in both Windows and on the Fog server.

So there’s something wrong with my CentOS install. I reinstalled it twice and followed the Wiki instructions to the T.

@george1421 Where is the output.pcap file saved?

@Sebastian-Roth Here’s the output of my iptables:

Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination

Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination

@Sebastian-Roth I disabled firewalld in CentOS.

@george1421 Edit: Misread the question.

Everything is on the same subnet. We’re on a .23 subnet. In fact all the devices I’m using for testing are plugged into the same switch.

I’ll work on getting the info you need.

@Sebastian-Roth Same error in Windows tftp test with firewall disabled. Its not an access denied so I’m fairly confident its not a firewall issue. I’m getting this on a VM and physical hardware install of CentOS 7.

Very strange. I even rebooted after the change for good measure.

@Sebastian-Roth Attached is output.

CentOS FW output.pdf