How to setup an DNS server ?

A DNS server can be hosted in any DOTNET CORE project like ASP.NET CORE or Console application. Follow the steps below to deploy a DNS server into a console application :

1. Create an empty Console application.
2. Install the Nuget package DnsServer.
3. In the Program.cs file, insert the following code into the Main method.
4. Configure the network interface to use the local DNS server.
5. Open a command prompt and execute ping www.example.com.

var dnsServer = new DnsServerHostBuilder(o =>
{
    o.ExcludeForwardRequests.Add(new Regex("^.*example\\.com$"));
    o.ExcludeForwardRequests.Add(new Regex("^.*in-addr\\.arpa$"));
})
.AddDNSZones(new List<DNSZone>
{
    new DNSZone("example.com")
    {
            ResourceRecords = new List<ResourceRecord>
            {
                    new AResourceRecord(3600)
                    {
                            Address = "127.0.0.1"
                    },
                    new AResourceRecord(3600, "www")
                    {
                            Address = "127.0.0.1"
                    },
                    new AResourceRecord(3600, "ns1")
                    {
                            Address = "127.0.0.1"
                    },
                    new SOAResourceRecord(3600)
                    {
                            MName = "ns1.example.com",
                            RName = "admin.example.com",
                            Serial = 5,
                            Refresh = 604800,
                            Expire = 2419200,
                            Minimum = 604800,
                            Retry = 86400
                    },
                    new NSResourceRecord(3600)
                    {
                            NSDName = "ns1.example.com"
                    }
            }
    },
    new DNSZone("1.0.0.127.in-addr.arpa")
    {
            ResourceRecords = new List<ResourceRecord>
            {
                    new PTRResourceRecord(100)
                    {
                            PTRDNAME = "localhost"
                    }
            }
    }
})
.AddDNSRootServers(DnsServerConstants.DefaultRootServers)
.Build();
dnsServer.Run();

The DnsServerHostBuilder class accepts in its constructor a callback which can be used by developers to change the options of the DNS server. There are several operations exposed by the DnsServerHostBuilder class :

• AddDNSZones : Configure DNS zones.
• AddDNSRootServers : Configure the DNS root servers.

A WPF client also exists here.