what does SocketOptionName.KeepAlive mean?

[Ryan Liu]

Hi,

SocketOptionName.KeepAlive is a bool or an int value?

Is it "belongs to" SocketOptionLevel.Socket?

What does value 0 means? Is that meaning always "keep alive", or never "send
keep-alives"?

And what does "Send keep-alives" mean anyway?

Thanks a million?
Ryan

[Dave Sexton]

Hi Ryan,

SocketOptionName.KeepAlive must be associated with a TCP Socket and supplied
as a Boolean value, true or false, to the SetSocketOption method.

See section 4.2.3.6 TCP Keep-Alives of RFC 1122 for the standardized
design:

http://www.faqs.org/rfcs/rfc1122.html

In short, enabling keep-alives causes a packet to be sent every 2 hours, by
default, to keep the connection alive when there has been no data sent by
the application within that 2 hour period. In practice, however, a Socket
connection will be closed long before that 2 hour period if no data is sent
within that interval.

- David Sexton

"Ryan Liu" <ad********@online.sh.cnwrote in message
news:O0**************@TK2MSFTNGP03.phx.gbl...

Hi,

SocketOptionName.KeepAlive is a bool or an int value?

Is it "belongs to" SocketOptionLevel.Socket?

What does value 0 means? Is that meaning always "keep alive", or never
"send
keep-alives"?

And what does "Send keep-alives" mean anyway?

Thanks a million?
Ryan

[DC]

>"In practice, however, a Socket connection will be closed long before that

>2 hour period >if no data is sent within that interval."

Why so Dave? I have never seen that happen.

"Dave Sexton" <dave@jwa[remove.this]online.comwrote in message
news:uI**************@TK2MSFTNGP05.phx.gbl...

Hi Ryan,

SocketOptionName.KeepAlive must be associated with a TCP Socket and
supplied as a Boolean value, true or false, to the SetSocketOption method.

See section 4.2.3.6 TCP Keep-Alives of RFC 1122 for the standardized
design:

http://www.faqs.org/rfcs/rfc1122.html

In short, enabling keep-alives causes a packet to be sent every 2 hours,
by default, to keep the connection alive when there has been no data sent
by the application within that 2 hour period. In practice, however, a
Socket connection will be closed long before that 2 hour period if no data
is sent within that interval.

- David Sexton

"Ryan Liu" <ad********@online.sh.cnwrote in message
news:O0**************@TK2MSFTNGP03.phx.gbl...

>Hi,

SocketOptionName.KeepAlive is a bool or an int value?

Is it "belongs to" SocketOptionLevel.Socket?

What does value 0 means? Is that meaning always "keep alive", or never
"send
keep-alives"?

And what does "Send keep-alives" mean anyway?

Thanks a million?
Ryan

[Dave Sexton]

Hi DC,

I was referring to the fact that sockets in .NET are used mostly for Web
Services, remoting or ASP.NET applications, which are all disconnected
models (i.e. one connection per request, although in remoting there may be
several requests per connection if submitted within a specific interval), or
custom services that have built-in timeouts way before 2 hours since the
longer a socket is left open the bigger the security risk. 2 hours is quite
a lot of time to wait for a response.

"DC" <***@***.comwrote in message
news:ux**************@TK2MSFTNGP05.phx.gbl...

"In practice, however, a Socket connection will be closed long before
that 2 hour period >if no data is sent within that interval."

Why so Dave? I have never seen that happen.

"Dave Sexton" <dave@jwa[remove.this]online.comwrote in message
news:uI**************@TK2MSFTNGP05.phx.gbl...

>Hi Ryan,

SocketOptionName.KeepAlive must be associated with a TCP Socket and
supplied as a Boolean value, true or false, to the SetSocketOption
method.

See section 4.2.3.6 TCP Keep-Alives of RFC 1122 for the standardized
design:

http://www.faqs.org/rfcs/rfc1122.html

In short, enabling keep-alives causes a packet to be sent every 2 hours,
by default, to keep the connection alive when there has been no data sent
by the application within that 2 hour period. In practice, however, a
Socket connection will be closed long before that 2 hour period if no
data is sent within that interval.

- David Sexton

"Ryan Liu" <ad********@online.sh.cnwrote in message
news:O0**************@TK2MSFTNGP03.phx.gbl...

>>Hi,

SocketOptionName.KeepAlive is a bool or an int value?

Is it "belongs to" SocketOptionLevel.Socket?

What does value 0 means? Is that meaning always "keep alive", or never
"send
keep-alives"?

And what does "Send keep-alives" mean anyway?

Thanks a million?
Ryan