UDP Ping Client and Server

This project consists of a UDP ping client and server written in C++.
The client sends UDP packets to the server, which echoes them back.
Useful for measuring round-trip time (RTT) and network diagnostics.

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Build Instructions

Requirements:

• g++ (GNU C++ compiler)
• Make

Build:

1. Run the following command to compile both the client and the server:

   make

2. To clean up object files and binaries:

   make clean

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Usage

1. UDP Ping Server

The server listens for incoming UDP packets and echoes them back to the sender.

Start the Server:

./udp-ping-server [-p port] [-a subnet]

Options:

• -p <port> – (Optional) Port to listen on. Default is 7777.
• -a <subnet> – (Optional) Allow packets from specific subnets.
  • Can be used multiple times to add multiple subnets.
  • If no subnet is specified, all IPs are allowed.

Examples:

• Start the server on the default port (7777) and allow all IPs:

  ./udp-ping-server

• Start the server on port 9000, allowing packets from 192.168.1.x and 10.0.0.x:

  ./udp-ping-server -p 9000 -a 192.168.1. -a 10.0.0.

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2. UDP Ping Client

The client sends UDP packets to the server and calculates the round-trip time (RTT).

Start the Client:

./udp-ping-client <server_ip_or_hostname> [-i interval] [-c count] [-d duration] [-s payload_size]

Options:

• -p <port> – (Optional) Port. Default is 7777.
• -i <interval> – (Optional) Interval between packets in seconds (supports fractions, e.g., 0.05). Default is 1 second.
• -c <count> – (Optional) Number of packets to send. Default is infinite.
• -d <duration> – (Optional) Stop after a specified duration (in seconds).
• -s <payload_size> – (Optional) Size of the payload in bytes. Default is 64 bytes.

Examples:

• Send packets to 192.168.0.10 every second, indefinitely:

  ./udp-ping-client 192.168.0.10

• Send packets every 50 ms for 30 seconds:

  ./udp-ping-client 192.168.0.10 -i 0.05 -d 30

• Send 100 packets with 512-byte payloads:

  ./udp-ping-client 192.168.0.10 -c 100 -s 512

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How It Works

• The client sends UDP packets containing a sequence number and timestamp.
• The server echoes the packets back.
• The client calculates round-trip time (RTT) for each packet and prints the result.
• High latency and packet loss are reported in the statistics.

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Example Output

Response - seq: 1, rtt: 16.35 ms
Response - seq: 2, rtt: 32.50 ms [HIGH LATENCY]
Response - seq: 3, rtt: 15.28 ms

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Notes:

• Performance Optimization: Logging for accepted packets is disabled to improve server performance.
• Only rejected packets from unauthorized IPs are logged.