NCP keep alive not settable for more than 2 hours

Setting the ncp tcp keepalive interval to anything more than 2 hours will not be honored and a keep alive will be sent on the 2 hour mark.
Setting the keep alive to anything less than 2 hours will send a keep alive at the sent interval.

Currently this issue is not seen to cause any problems. If ncp keep alives are suspected of causing any type of problem they can be disabled by setting it to 0.

The default ncp tcp keep alive interval is about 10 minutes. Typically if an application does not set the keep alive timer the tcp stack will default the timer to 2 hours.