Computer Networks

Hands-on networking work in one place: a virtual routing lab built from Linux VMs and VyOS routers, and a socket-based group messaging system in C++. The larger load-balancing project lives in its own repository.

Part	What it is	Highlights
routing-lab/	Two Ubuntu hosts and two VyOS routers on Linux bridges under QEMU/KVM, with static routing for IPv4 and IPv6	3-hop path, dual-stack ping and traceroute, iperf throughput, router and host configs
messaging-system/	Group messaging with a TCP control channel, UDP multicast data path, IPv4 and IPv6, hostname resolution and TLS	Select-based I/O multiplexing, per-group multicast addresses, timestamps and timing on the echo service
LoadBalancerLab	Discrete-event load-balancer simulator with a real-process deployment path and a Prequal paper reproduction	Separate repository

Routing lab at a glance

flowchart LR
    H1["H1 (Ubuntu)<br/>10.0.1.10<br/>10:0:1::10"] --- B1(["bri1<br/>10.0.1.0/24"])
    B1 --- R1["R1 (VyOS)<br/>eth0 10.0.1.254<br/>eth1 10.0.2.1"]
    R1 --- B2(["bri2<br/>10.0.2.0/24"])
    B2 --- R2["R2 (VyOS)<br/>eth0 10.0.2.254<br/>eth1 10.0.3.1"]
    R2 --- B3(["bri3<br/>10.0.3.0/24"])
    B3 --- H2["H2 (Ubuntu)<br/>10.0.3.10<br/>10:0:3::10"]

Loading

H1 reaches H2 across both routers in three hops over IPv4 and IPv6, with about 11.7 ms average round trip and 4.3 Gbit/s TCP throughput measured by iperf. Details and screenshots are in routing-lab/.

Messaging system at a glance

A server and several clients communicate over two planes: TCP carries group management (create, join, leave), and UDP multicast carries the group messages. A separate TCP echo service supports plain and TLS connections and reports receive and send timestamps and timings. See messaging-system/README.md for architecture, commands and build steps.

cd messaging-system
g++ -std=c++17 -Wall -Wextra -O2 server.cpp -o server -lssl -lcrypto -pthread
g++ -std=c++17 -Wall -Wextra -O2 client.cpp -o client -lssl -lcrypto -pthread

License

MIT, see LICENSE.