Elastic keep-alive system and method for virtual cross-domain communication

The invention provides an elastic keep-alive system and method for virtual cross-domain communication. A source end router is used for elastically sending a virtual link state keep-alive message according to a link state updating period; a destination end router is used for receiving the message sent by the source end router and sending a message receipt to the source end router; a state monitoring module is used for monitoring whether the virtual passing link is in an idle state or not, wherein the link state update is used for determining the interval time of link update according to the number of times of link state update, and triggering the source end router to send a message at different time according to different interval time. The interval time of virtual link updating is determined according to the number of virtual link state updating times, and the defect that a link state updating message cannot work elastically during cross-domain communication of a current virtual communication protocol is over