I wasn't very familiar with dot1q tunneling aka Q-in-Q. But since I started working for a service provider, I was more and more involved with this technology almost on a daily basis. So I started researching and reading more about. While studying and reviewing switching topics, I came across dot1q and while implementing the INE lab, I noticed a few things that I thought this is worth a post here and it is officially my first study post! So enough talking and let's start tagging!! QinQ is simply a techniuq used (mainly by ISPs) to keep traffic from customers segregated within the ISP's cloud. Suppose Customer A has 2 sites and it needs to have both sites privately connected within the ISP