> But the onus was on me to prove it by finding the bug. As a network engineer who has had to prove numerous times that "it's not the firewall" or "it's not th

> But the onus was on me to prove it by finding the bug. As a network engineer who has had to prove numerous times that "it's not the firewall" or "it's not the network", you have my deepest sympathies. -- Story time: My most memorable instance of this was when I worked at a .edu and was going through yet another iteration of the back-and-forth, "it's not on our side, must be on your side", "no, it's not us, it's your firewall", finger-pointing blame game. This particular issue had been dragging on for a while and, eventually, I got a packet capture from their side (packet captures are, to me, the ultimate source of truth, "the last word"). Yet, even after showing (and explaining) it to them, they continued to insist that their firewall was absolutely, positively, 100% configured properly and, thus, it had to be my firewall which was not properly configured. Finally, I called in a favor from a (Ph.D.) faculty member who "owed me one". After explaining what was going on and, more importantly, showing him the timestamps, he agreed to help me out. He wrote up a wonderful e-mail (which I still have a copy of, somewhere) stating how it just was not possible, literally, that mine was the "offending firewall". He explained how he was able to conclude this with absolute certainty, thanks to the laws of physics and politely suggested that -- unless they had evidence that Checkpoint was able to somehow violate those laws of physics (in which case he would be extremely interested in their proof) -- that perhaps they might wanna take another look at their firewall? I waited anxiously, curious what the response (and latest excuse) would be. A few days passed before, finally, an e-mail appeared in my inbox. I quickly opened it and read the one-line reply: We found the problem, it's working now.