This course on Computer Networks is intended for both undergraduate and postgraduate students. It consists of lectures on different protocols used in computer networks. The protocols will be taught according to the TCP/IP Protocol suite. The students will get detailed knowledge about the functioning of different layers of the TCP/IP Protocol suite. The different protocols at application layer like HTTP, FTP, DNS, SMTP , Transport Layer Protocols like TCP, UDP, Network layer protocols like IPv4, IPv6 etc will be taught. The students will also get knowledge of setting up Network, LAN, VLAN etc. There will also be a focus on different vulnerabilities in the Network, possible attacks on Network and countermeasures will be discussed. Discussion of different Network architectures like Client Server, Peer to Peer will be helpful for understanding different concepts by the students. I will be teaching computer networks with reference to Computer Networks A Top Down approach by Kurose Ross.