python import yaml from ipaddress import ip_network, IPv4Network

1. Write Python object "switches" to YAML

switches = [ {"vendor": "cisco", "model": "2960"}, {"vendor": "juniper", "model": "ex2200"}, {"vendor": "cisco", "model": "3750"}, ]

with open("switches.yaml", "w") as f: yaml.dump(switches, f)

2. Keep only cisco switches

cisco_switches = [sw for sw in switches if sw["vendor"] == "cisco"]

3. Get the last host address in the network 172.16.0.0/28

network = ip_network("172.16.0.0/28") last_host = list(network.hosts())[-1]

4. Parse dhcp_snooping_table

dhcp_snooping_table = """ 00:E9:BC:3F:A6:50 100.1.1.6 FastEthernet0/20 00:E9:22:11:A6:50 100.1.1.7 FastEthernet0/21 """

dhcp_snooping_table_parsed = [] for line in dhcp_snooping_table.strip().splitlines(): mac, ip, interface = line.split() dhcp_snooping_table_parsed.append({"mac": mac, "ip": ip, "interface": interface})

5. NetworkSubnet class

class NetworkSubnet: def init(self, aggregate_network: str): self.aggregate = ip_network(aggregate_network) self.available_subnets = [self.aggregate]

def get_subnet(self, length: int) -> IPv4Network:
    for i, subnet in enumerate(self.available_subnets):
        if subnet.prefixlen <= length:
            # Split the subnet into smaller ones
            subnets = list(subnet.subnets(new_prefix=length))
            # Take the first subnet
            chosen = subnets[0]
            # Update the pool of available subnets
            self.available_subnets.pop(i)
            self.available_subnets.extend(subnets[1:])
            self.available_subnets.sort(key=lambda x: int(x.network_address))
            return chosen
    raise ValueError("No available subnets of the required length")

def show_network_pool(self) -> list[IPv4Network]:
    return self.available_subnets

Example usage

net = NetworkSubnet(aggregate_network="172.16.0.0/24") net_1 = net.get_subnet(length=26) print(f"{net_1=}") # 172.16.0.0/26 print(net.get_subnet(length=25)) # 172.16.0.64/25 print(net.get_subnet(length=30)) # 172.16.0.192/30 print(net.show_network_pool()) # Remaining subnets