How to Implement Multi level Firewall in OMNeT++
To implement the multi-level firewall in OMNeT++ required a simulation process in which they had various firewall rules are applicable at many levels of the network involves the separate hosts, at network gateways, or across several network segments. This kind is very helpful for studying the efficiency of security policies, traffic filtering, and the influence of firewalls on network performance.
Here’s a step-by-step guide to implementing a multi-level firewall in OMNeT++ with examples:
Step-by-Step Implementation:
Step 1: Set Up the OMNeT++ Environment
Make certain that OMNeT++ and essential libraries like INET are installed and configured properly. INET offers models for networking protocols and devices, which you can extend to contain firewall functionality.
Step 2: Define the Firewall Module
Start by generating a firewall module which will be used to investigate and filter packets depends on rules. This module can be placed at various levels in the network like on separate nodes or at a network gateway.
Example Firewall Module Definition
module Firewall
{
parameters:
string allowedIpAddresses[]; // List of allowed IP addresses
int allowedPorts[]; // List of allowed ports
@display(“i=block/Firewall”); // Icon for visualization
gates:
inout ethg; // Ethernet communication gate
submodules:
eth: <default(“EthernetInterface”)>; // Ethernet NIC for communication
connections:
ethg <–> eth.physIn;
}
Step 3: Implement Firewall Logic
Execute the logic for filtering packets according to the IP addresses, ports, and other criteria. The firewall will decide whether to forward, block, or log the packets.
Example Firewall Logic (Simplified)
class Firewall : public cSimpleModule
{
protected:
virtual void handleMessage(cMessage *msg) override;
private:
std::vector<std::string> allowedIpAddresses;
std::vector<int> allowedPorts;
bool isAllowed(cMessage *msg);
};
void Firewall::handleMessage(cMessage *msg)
{
if (isAllowed(msg))
{
EV << “Packet allowed: ” << msg->getName() << endl;
send(msg, “ethg$o”);
}
else
{
EV << “Packet blocked: ” << msg->getName() << endl;
delete msg;
}
}
bool Firewall::isAllowed(cMessage *msg)
{
// Simplified example: Check if the packet’s destination IP and port are allowed
const char *destIp = msg->par(“destIp”).stringValue();
int destPort = msg->par(“destPort”).intValue();
if (std::find(allowedIpAddresses.begin(), allowedIpAddresses.end(), destIp) != allowedIpAddresses.end() &&
std::find(allowedPorts.begin(), allowedPorts.end(), destPort) != allowedPorts.end())
{
return true;
}
return false;
}
Step 4: Define Multi-Level Firewall Network Scenario
Generate a network scenario where firewalls are deployed at several levels. It contains firewalls on several hosts, at the network gateway, or in certain parts of the network.
Example Multi-Level Firewall Network Scenario Definition
network MultiLevelFirewallNetwork
{
parameters:
int numHosts = default(3); // Number of hosts in the network
int numGateways = default(1); // Number of gateways
submodules:
gateways[numGateways]: Firewall {
@display(“p=300,300”);
}
hosts[numHosts]: Firewall {
@display(“p=100,100”);
}
connections allowunconnected:
for i=0..numHosts-1 {
hosts[i].ethg <–> EthernetCable <–> gateways[0].ethg;
}
}
Step 5: Configure the Simulation Parameters
Set up the simulation parameters in the .ini file, containing firewall rules for various levels, like allocated IPs and ports.
Example Configuration in the .ini File
network = MultiLevelFirewallNetwork
sim-time-limit = 300s
# Firewall rules for hosts
*.hosts[*].allowedIpAddresses = “192.168.1.1”, “192.168.1.2”
*.hosts[*].allowedPorts = 80, 443
# Firewall rules for gateway
*.gateways[0].allowedIpAddresses = “192.168.1.0/24” # Allow entire subnet
*.gateways[0].allowedPorts = 80, 443, 22
# Set up Ethernet communication parameters
*.hosts[*].eth.datarate = 100Mbps
*.gateways[0].eth.datarate = 1Gbps
Step 6: Implement Traffic Generation (Hosts)
Examine the firewall rules by executing the logic for creating network traffic from the hosts.
Example Traffic Generation Logic (Simplified)
class TrafficGenerator : public cSimpleModule
{
protected:
virtual void initialize() override;
virtual void handleMessage(cMessage *msg) override;
private:
cMessage *sendTimer; // Timer to trigger sending data
std::string destIp;
int destPort;
};
void TrafficGenerator::initialize()
{
destIp = par(“destIp”).stringValue();
destPort = par(“destPort”).intValue();
sendTimer = new cMessage(“sendTimer”);
scheduleAt(simTime() + par(“sendInterval”), sendTimer);
}
void TrafficGenerator::handleMessage(cMessage *msg)
{
if (msg == sendTimer)
{
EV << “Sending packet to ” << destIp << ” on port ” << destPort << endl;
cMessage *packet = new cMessage(“DataPacket”);
packet->addPar(“destIp”) = destIp.c_str();
packet->addPar(“destPort”) = destPort;
send(packet, “ethg$o”);
scheduleAt(simTime() + par(“sendInterval”), sendTimer);
}
else
{
delete msg;
}
}
Step 7: Run the Simulation
Compile and run the simulation. Monitor how the multi-level firewalls filter traffic based on the configured rules. Check the logs to verify that the correct packets are being allot or blocked.
Step 8: Analyze the Results
Use OMNeT++’s analysis tools to estimate the performance of the multi-level firewall setup. Assess metrics like:
- Packet Delivery Ratio: The percentage of allot packets that successfully reach their destination.
- Firewall Effectiveness: How well the firewalls block illegal access based on IP and port filtering.
- Network Performance: The influence of firewall rules on network performance, containing latency and throughput.
Step 9: Extend the Simulation (Optional)
You can extend the simulation by:
- Implementing Stateful Firewalls: Optimize the firewall logic to find the state of connections and allow or block traffic depends on connection states.
- Simulating Firewall Bypass Attacks: Examine the robustness of the firewall by simulating several attack situations like port scanning or spoofing.
- Adding More Firewall Levels: Execute additional firewalls at various network levels like amongst several subnets or for certain applications.
- Testing with Different Traffic Patterns: Generate various kinds of traffic (e.g., HTTP, FTP, P2P) and monitor how the firewall monitor them.
By using this procedure, you will gain the knowledge on how to implement the multi-level firewall in OMNeT++ and also configure the traffic generation logic by using INET framework. We can also provide the extra details regarding this firewall, if needed.
In order to implement a multi-level firewall in OMNeT++, please discuss the specifics of your project with us. You may rely on our professionals for any kind of project execution; we’ll share the greatest project ideas and themes with you.