 So, now that we have seen how does the connection-oriented protocol TCP work and how does the connection less protocol called UDP work, let's go into packet tracer and see how this action happens in a virtual network. Welcome to this video on transport layer in packet tracer. In this video, we are going to see two concepts of TCP and UDP in transport layer. We have already seen that TCP is a connection-oriented protocol and UDP is a connection less protocol. So, we'll look in detail how does these two work. Here I have the same network which we which you have been seeing from past couple of weeks. I have a campus network here with this being the network of a hostel and this being the backbone and the campus web server which is connecting the computers on the campus computers and devices on the campus to the outside world. Let us try to access a website from a laptop from a hostel and see when a website is being accessed, it initially sends a DNS request, DNS protocol works on top of UDP so we can also see how UDP works while we access a website. But before that, you have to make sure that we have to make sure that we have turned on all the required packets to be seen in the simulation mode. Let us go and try to access a website called hotel.com. You can see that a DNS request is made and if we go and see the DNS request, you can see that it is working on top of UDP protocol. Both the protocols in the transport layer TCP and UDP make use of what are known as port numbers. So, here we can see that a port number of 1041 has been assigned as the source port and destination port is 53 which is the port number for DNS service. So, the DNS request is wrapped in a UDP packet encapsulated in a UDP segment and it is sent off the network. Now what happened was the laptop sent a DNS query to its DNS server and got back a reply. If you compare the path travelled by the DNS packets while going and while coming back, it need not be the same path because DNS traverses on UDP which is a connection less protocol.