I think eager-ACK is harmful.
How do you think about these two problem?
1 A detour router crash causes breaking all TCP connection on it.
if one doesn't use detour router, a crash of a router causes changing
the routing tables and existing TCP connection will eventually select
a new route with keeping the same TCP connection.
in the case of detour router crash, eager-ACKed packets were lost and
unrecoverable. this causes breaking the TCP connection. and both or
either end must restart a new TCP connection.
Isn't this a problem for long-lived persistent applications?
examples of these application:
o 24-7 connected telnet session.
o VPN or some tunnel connections.
2 KeepAlive doesn't work as expected.
Some application uses KeepAlive to detect the failure of the route
when they doesn't transferring any packet.
Should the detour router eager-ACK to KeepAlive datagram?
-- Kenichi Ishikawa