FWIW, keepalives are also used to help use TCP as a "reachability
detector" for routing protocols as well.
Joe
On 7/14/2016 5:18 PM, Daniel B Giffin wrote:
>> > - Section 3.9 gives the justification for sending keep-alives as "for
>> > applications to ensure that the other end of a TCP connection still exists
>> > even when there is no data to be sent." That may be true, but another big
>> > reason for sending keep-alives is to keep sessions alive in middleboxes,
>> > especially NAT boxes and to a lesser degree firewalls. These middleboxes
>> > have been known to lose state after as little as 30 seconds ("behave" WG
>> > admonitions notwithstanding) and to block or mangle subsequent
>> > "out-of-state” packets.
> Good point -- I've added this consideration to the new
> "Design notes" section.
>
_______________________________________________
Tcpinc mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/tcpinc
