Wireshark is my favourite "I told you so" tool. You can't imagine how useful it is for network troubleshooting. Heck, It's been many times that I've told a cus

Wireshark is my favourite "I told you so" tool. You can't imagine how useful it is for network troubleshooting. Heck, It's been many times that I've told a customer "you've got this device running this OS in your network doing DPI/ALG/etc and it's probably sitting points at the network diagram exactly here, which you conveniently forgot to add to the diagram" just by looking at a network trace with Wireshark.