SocketOptionName Enum

Definition

Namespace:

System.Net.Sockets

Assembly:

System.Net.Sockets.dll

Defines configuration option names.

public enum class SocketOptionName

public enum SocketOptionName

type SocketOptionName = 

Public Enum SocketOptionName

Inheritance

Object

ValueType

Enum

SocketOptionName

Fields

Name	Value	Description
DontLinger	-129	Close the socket gracefully without lingering.
ExclusiveAddressUse	-5	Enables a socket to be bound for exclusive access.
Debug	1	Record debugging information.
IPOptions	1	Specifies the IP options to be inserted into outgoing datagrams.
NoChecksum	1	Send UDP datagrams with checksum set to zero.
NoDelay	1	Disables the Nagle algorithm for send coalescing.
AcceptConnection	2	The socket is listening.
BsdUrgent	2	Use urgent data as defined in RFC-1222. This option can be set only once; after it is set, it cannot be turned off.
Expedited	2	Use expedited data as defined in RFC-1222. This option can be set only once; after it is set, it cannot be turned off.
HeaderIncluded	2	Indicates that the application provides the IP header for outgoing datagrams.
TcpKeepAliveTime	3	The number of seconds a TCP connection will remain alive/idle before keepalive probes are sent to the remote.
TypeOfService	3	Change the IP header type of the service field.
IpTimeToLive	4	Set the IP header Time-to-Live field.
ReuseAddress	4	Allows the socket to be bound to an address that is already in use.
KeepAlive	8	Use keep-alives.
MulticastInterface	9	Set the interface for outgoing multicast packets.
MulticastTimeToLive	10	An IP multicast Time to Live.
MulticastLoopback	11	An IP multicast loopback.
AddMembership	12	Add an IP group membership.
DropMembership	13	Drop an IP group membership.
DontFragment	14	Do not fragment IP datagrams.
AddSourceMembership	15	Join a source group.
FastOpen	15	Enables TCP Fast Open as defined in RFC-7413. The actual observed behavior depends on OS configuration and the state of the kernel TCP cookie cache. Enabling TFO can impact interoperability and cause connectivity issues.
DontRoute	16	Do not route; send the packet directly to the interface addresses.
DropSourceMembership	16	Drop a source group.
TcpKeepAliveRetryCount	16	The number of TCP keep alive probes that will be sent before the connection is terminated.
BlockSource	17	Block data from a source.
TcpKeepAliveInterval	17	The number of seconds a TCP connection will wait for a keepalive response before sending another keepalive probe.
UnblockSource	18	Unblock a previously blocked source.
PacketInformation	19	Return information about received packets.
ChecksumCoverage	20	Set or get the UDP checksum coverage.
HopLimit	21	Specifies the maximum number of router hops for an Internet Protocol version 6 (IPv6) packet. This is similar to Time to Live (TTL) for Internet Protocol version 4.
IPProtectionLevel	23	Enables restriction of a IPv6 socket to a specified scope, such as addresses with the same link local or site local prefix. This socket option enables applications to place access restrictions on IPv6 sockets. Such restrictions enable an application running on a private LAN to simply and robustly harden itself against external attacks. This socket option widens or narrows the scope of a listening socket, enabling unrestricted access from public and private users when appropriate, or restricting access only to the same site, as required. This socket option has defined protection levels specified in the IPProtectionLevel enumeration.
IPv6Only	27	Indicates if a socket created for the AF_INET6 address family is restricted to IPv6 communications only. Sockets created for the AF_INET6 address family may be used for both IPv6 and IPv4 communications. Some applications may want to restrict their use of a socket created for the AF_INET6 address family to IPv6 communications only. When this value is non-zero (the default on Windows), a socket created for the AF_INET6 address family can be used to send and receive IPv6 packets only. When this value is zero, a socket created for the AF_INET6 address family can be used to send and receive packets to and from an IPv6 address or an IPv4 address. Note that the ability to interact with an IPv4 address requires the use of IPv4 mapped addresses. This socket option is supported on Windows Vista or later.
Broadcast	32	Permit sending broadcast messages on the socket.
UseLoopback	64	Bypass hardware when possible.
Linger	128	Linger on close if unsent data is present.
OutOfBandInline	256	Receives out-of-band data in the normal data stream.
SendBuffer	4097	Specifies the total per-socket buffer space reserved for sends. This is unrelated to the maximum message size or the size of a TCP window.
ReceiveBuffer	4098	Specifies the total per-socket buffer space reserved for receives. This is unrelated to the maximum message size or the size of a TCP window.
SendLowWater	4099	Specifies the low water mark for Send operations.
ReceiveLowWater	4100	Specifies the low water mark for Receive operations.
SendTimeout	4101	Send a time-out. This option applies only to synchronous methods; it has no effect on asynchronous methods such as the BeginSend(Byte[], Int32, Int32, SocketFlags, AsyncCallback, Object) method.
ReceiveTimeout	4102	Receive a time-out. This option applies only to synchronous methods; it has no effect on asynchronous methods such as the BeginSend(Byte[], Int32, Int32, SocketFlags, AsyncCallback, Object) method.
Error	4103	Gets the error status and clear.
Type	4104	Gets the socket type.
ReuseUnicastPort	12295	Indicates that the system should defer ephemeral port allocation for outbound connections. This is equivalent to using the Winsock2 SO_REUSE_UNICASTPORT socket option.
UpdateAcceptContext	28683	Updates an accepted socket's properties by using those of an existing socket. This is equivalent to using the Winsock2 SO_UPDATE_ACCEPT_CONTEXT socket option and is supported only on connection-oriented sockets.
UpdateConnectContext	28688	Updates a connected socket's properties by using those of an existing socket. This is equivalent to using the Winsock2 SO_UPDATE_CONNECT_CONTEXT socket option and is supported only on connection-oriented sockets.
MaxConnections	2147483647	Not supported; will throw a SocketException if used.

Examples

The following code example uses this enumeration to set socket options.

// Specifies that the Socket will linger for 10 seconds after Close is called.
LingerOption^ lingerOption = gcnew LingerOption(true, 10);
s->SetSocketOption(SocketOptionLevel::Socket, SocketOptionName::Linger, lingerOption);

// The socket will linger for 10 seconds after Socket.Close is called.
var lingerOption = new LingerOption(true, 10);
s.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Linger, lingerOption);

' The socket will linger for 10 seconds after Socket.Close is called.
Dim lingerOption As New LingerOption(True, 10)
s.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Linger, lingerOption)

Remarks

The SocketOptionName enumeration defines the name of each Socket configuration option. Sockets can be configured with the Socket.SetSocketOption method.

See also

• SocketOptionLevel
• SocketOptionName