PrefixOrigin Enumeration

 

Specifies how an IP address network prefix was located.

Namespace:   System.Net.NetworkInformation
Assembly:  System (in System.dll)

Public Enumeration PrefixOrigin

Member nameDescription
Dhcp

The prefix was supplied by a Dynamic Host Configuration Protocol (DHCP) server.

Manual

The prefix was manually configured.

Other

The prefix was located using an unspecified source.

RouterAdvertisement

The prefix was supplied by a router advertisement.

WellKnown

The prefix is a well-known prefix. Well-known prefixes are specified in standard-track Request for Comments (RFC) documents and assigned by the Internet Assigned Numbers Authority (Iana) or an address registry. Such prefixes are reserved for special purposes.

IP addresses are divided into two parts: the prefix and the suffix. The address prefix identifies the network portion of an IP address, and the address suffix identifies the host portion. Prefixes are assigned by global authorities, and suffixes are assigned by local system administrators.

This enumeration is used by the UnicastIPAddressInformation and MulticastIPAddressInformation classes. Instances of this class are returned when you retrieve the address information for a NetworkInterface object.

The following code example displays prefix and suffix information for unicast addresses.

Public Shared Sub DisplayUnicastAddresses() 

    Console.WriteLine("Unicast Addresses")
    Dim adapters As NetworkInterface() = NetworkInterface.GetAllNetworkInterfaces()
    Dim adapter As NetworkInterface
    For Each adapter In  adapters
        Dim adapterProperties As IPInterfaceProperties = adapter.GetIPProperties()
        Dim uniCast As UnicastIPAddressInformationCollection = adapterProperties.UnicastAddresses
        If uniCast.Count > 0 Then
            Console.WriteLine(adapter.Description)
            Dim lifeTimeFormat As String = "dddd, MMMM dd, yyyy  hh:mm:ss tt"
            Dim uni As UnicastIPAddressInformation
            For Each uni In  uniCast
                Dim [when] As DateTime

                Console.WriteLine("  Unicast Address ......................... : {0}", uni.Address)
                Console.WriteLine("     Prefix Origin ........................ : {0}", uni.PrefixOrigin)
                Console.WriteLine("     Suffix Origin ........................ : {0}", uni.SuffixOrigin)
                Console.WriteLine("     Duplicate Address Detection .......... : {0}", uni.DuplicateAddressDetectionState)

                ' Format the lifetimes as Sunday, February 16, 2003 11:33:44 PM
                ' if en-us is the current culture.
                ' Calculate the date and time at the end of the lifetimes.    
                [when] = DateTime.UtcNow + TimeSpan.FromSeconds(uni.AddressValidLifetime)
                [when] = [when].ToLocalTime()
                Console.WriteLine("     Valid Life Time ...................... : {0}", [when].ToString(lifeTimeFormat, System.Globalization.CultureInfo.CurrentCulture))
                [when] = DateTime.UtcNow + TimeSpan.FromSeconds(uni.AddressPreferredLifetime)
                [when] = [when].ToLocalTime()
                Console.WriteLine("     Preferred life time .................. : {0}", [when].ToString(lifeTimeFormat, System.Globalization.CultureInfo.CurrentCulture))

                [when] = DateTime.UtcNow + TimeSpan.FromSeconds(uni.DhcpLeaseLifetime)
                [when] = [when].ToLocalTime()
                Console.WriteLine("     DHCP Leased Life Time ................ : {0}", [when].ToString(lifeTimeFormat, System.Globalization.CultureInfo.CurrentCulture))
            Next uni
            Console.WriteLine()
        End If
    Next adapter

End Sub 'DisplayUnicastAddresses

.NET Framework
Available since 2.0
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