RFC 1122:Requirements for Internet Hosts -- Commun...
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Active


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... Active probes such as "pinging" (i.e., using an ICMP ...
... (b) The route cache may be consulted, to see if there is an active route to the specified destination network ...
... IP layer is initialized and remain a member for as long as the IP layer is active. ...


... state as the result of a passive OPEN or an active OPEN. ...
... keep-alive mechanism. To confirm that an idle connection is still active, these implementations send a probe segment ...
... For an active OPEN call, a specified "local IP address" parameter will be used for opening the connection ...



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