To simulate the classless routing protocols using MATLAB that need to operate with protocols such as CIDR (Classless Inter-Domain Routing) or RIP v2 (Routing Information Protocol Version 2) that utilize variable-length subnet masks (VLSM) and do not depend on the predefined class-based addressing system (Class A, B, or C). In classless protocols, IP addresses and subnet masks are openly contained in the routing tables and routing updates.
We offer a simple guide on how to simulate classless routing protocols in MATLAB:
Steps to Simulate Classless Routing Protocols
- Define the Network Topology:
- Make a network of nodes (routers) and describe its connections (links).
- Allocate every single node an IP address and a subnet mask (CIDR notation).
Example:
% Number of routers (nodes) in the network
num_routers = 5;
% Assign IP addresses with CIDR notation (Classless)
% Example: Router 1 has 192.168.1.0/24, Router 2 has 192.168.2.0/24
ip_addresses = {‘192.168.1.0/24’, ‘192.168.2.0/24’, ‘192.168.3.0/24’, ‘192.168.4.0/24’, ‘192.168.5.0/24’};
% Adjacency matrix representing direct links between routers
adjacency_matrix = [0 1 0 0 1;
1 0 1 0 0;
0 1 0 1 0;
0 0 1 0 1;
1 0 0 1 0];
% Plot network topology
G = graph(adjacency_matrix, ip_addresses);
plot(G, ‘EdgeLabel’, G.Edges.Weight, ‘NodeLabel’, ip_addresses);
title(‘Network Topology with Classless IP Addresses’);
- Assign Subnet Masks and Network Addresses (CIDR):
- In classless routing protocols, IP addresses are joined with subnet masks making flexible and efficient addressing schemes. CIDR notation like 192.168.1.0/24 that denotes the network address and the length of the network prefix.
% Assign subnet masks for each router (CIDR notation)
subnet_masks = {‘255.255.255.0’, ‘255.255.255.0’, ‘255.255.255.0’, ‘255.255.255.0’, ‘255.255.255.0’};
- Create a Routing Table:
- Every single router sustains a routing table that encompasses destination networks, next-hop information, and subnet masks.
- Classless routing protocols such as RIP v2 and OSPF contain both destination network and subnet mask within routing updates.
Example of routing table for a router:
% Initialize routing table for each router
routing_table = cell(num_routers, 1);
% Example routing table entry for Router 1
% Format: {Destination Network, Subnet Mask, Next Hop, Metric (Distance)}
routing_table{1} = {
‘192.168.2.0’, ‘255.255.255.0’, ‘192.168.1.1’, 1;
‘192.168.3.0’, ‘255.255.255.0’, ‘192.168.2.1’, 2
};
% Similarly, populate the routing tables for other routers
- Routing Protocol (RIP v2 as an Example):
- RIP v2 is a classless routing protocol, which transmits routing updates comprising both the destination network and their subnet mask. It utilizes the hop count as a routing metric.
Example of RIP v2 routing update simulation:
% Simulate RIP v2 routing update process
% Router 1 sends routing updates to its neighbors
current_router = 1; % Router 1
for i = 1:num_routers
if adjacency_matrix(current_router, i) % If Router i is a neighbor
fprintf(‘Router %d sending routing update to Router %d\n’, current_router, i);
% Merge Router 1’s routing table into Router i’s routing table
for j = 1:size(routing_table{current_router}, 1)
destination_network = routing_table{current_router}{j, 1};
subnet_mask = routing_table{current_router}{j, 2};
metric = routing_table{current_router}{j, 4} + 1; % Increment metric
next_hop = routing_table{current_router}{j, 3};
% Check if Router i already has the route
route_exists = false;
for k = 1:size(routing_table{i}, 1)
if strcmp(routing_table{i}{k, 1}, destination_network) && strcmp(routing_table{i}{k, 2}, subnet_mask)
route_exists = true;
% Update the route if the new one has a better metric
if metric < routing_table{i}{k, 4}
routing_table{i}{k, 3} = next_hop;
routing_table{i}{k, 4} = metric;
end
break;
end
end
% Add the route if it doesn’t already exist
if ~route_exists
routing_table{i} = [routing_table{i}; {destination_network, subnet_mask, next_hop, metric}];
end
end
end
end
- Simulate Packet Forwarding:
- When the routing tables are found then replicate the packet forwarding according to the optimal path (lowest metric) within the routing table.
Example:
% Simulate packet forwarding from Router 1 to Router 3
source_router = 1;
destination_network = ‘192.168.3.0’;
current_router = source_router;
while ~strcmp(routing_table{current_router}{1, 1}, destination_network)
% Find next hop
next_hop = routing_table{current_router}{1, 3}; % Assuming next hop is the first entry in the routing table
fprintf(‘Forwarding packet from Router %d to Router %s\n’, current_router, next_hop);
% Move to next router
current_router = find(strcmp(ip_addresses, next_hop));
end
- Analyze Performance and Metrics:
- Latency: Compute how long it takes for packets to move from the origin to the destination.
- Hop Count: Calculate the amount of hops is taken to attain the destination.
- Energy Consumption (Optional): Execute an energy models for transmission and reception if replicating a wireless situation.
- Convergence Time: Estimate how long it takes for every router to know the comprehensive topology via routing updates.
Example of performance analysis:
% Measure number of hops
num_hops = size(routing_table{source_router}, 1);
fprintf(‘Packet took %d hops to reach the destination.\n’, num_hops);
% Plot the final routing table for Router 1
disp(‘Final Routing Table for Router 1:’);
disp(routing_table{1});
- Loop Over Multiple Rounds:
- For large-scale simulation, we can execute the simulation for several rounds in which diverse routers probably fail or new routes are found.
Example:
% Simulate multiple rounds of routing updates
rounds = 10;
for round = 1:rounds
for router = 1:num_routers
% Send routing updates and update routing tables (steps 4-5)
% This can be encapsulated into a function for cleaner code
end
end
Simulating Other Classless Protocols:
- OSPF (Open Shortest Path First):
- OSPF is a link-state routing protocol to calculate the finest path, which utilizes Dijkstra’s shortest path algorithm.
- In OSPF, routers swap Link State Advertisements (LSAs) to construct a comprehensive map of the network.
- We can change the above simulation to utilize Dijkstra’s algorithm for shortest path routing.
- BGP (Border Gateway Protocol):
- BGP is other classless protocol utilized for inter-domain routing. It depends on path vectors instead of the distance parameters.
In this project, we understood how to create a routing table, routing protocol and how to simulate Classless Protocol project and analyze their performance using MATLAB tool and also we provided some other classless protocol through simulation procedure. We will deliver likewise further information on this topic in upcoming manual. We at phdprime.com will help you achieve great results in simulating classless protocol projects using MATLAB. We provide customized project ideas and conduct performance analysis based on your interests. We work with protocols like CIDR (Classless Inter-Domain Routing) and RIP v2 (Routing Information Protocol Version 2).