Mac Pro TCP/IP stops working

Good morning,

I have a new problem with networking on my Mac Pro. Beginning on 7/23, it would stop sending packets out of the network. When this happens, I can ping 127.0.0.1, but I cannot ping my local 192.168.x.y address from my own machine. Other machines on the network, however can ping that IP.

The troubleshooting I've tried so far:

1. Disabled WiFi and connected only via en0
2. Disabled WiFi and connected only via en1
3. Disabled en0 and en1 and connected only via WiFi
4. Turned off firewall
5. Turned off antivirus solution
6. Manually assigned IP, Gateway and DNS

So far none of those have done the trick. The only "fix" is a reboot, and then networking works for 30 minutes up to a few hours.

Are there other diagnostics I can do when the problem occurs? Or is there something I can have running to capture traffic for analysis after the fact? Any insight would be appreciated.