> - TCP double ack fixed
Not for me it seems. Using ppp over a 9600 baud serial line:
--------tcpdump output-----------------------
13:25:36.670983 sable.ox.ac.uk.7777 > oban.1073: . 41840:42376(536) ack 392 win 33232
13:25:36.670983 oban.1073 > sable.ox.ac.uk.7777: . ack 42376 win 29449
13:25:36.670983 oban.1073 > sable.ox.ac.uk.7777: . ack 42376 win 29449
13:25:37.250983 sable.ox.ac.uk.7777 > oban.1073: . 42376:42912(536) ack 392 win 33232
13:25:37.250983 oban.1073 > sable.ox.ac.uk.7777: . ack 42912 win 29449
13:25:37.250983 oban.1073 > sable.ox.ac.uk.7777: . ack 42912 win 29449
13:25:37.820983 sable.ox.ac.uk.7777 > oban.1073: . 42912:43448(536) ack 392 win 33232
13:25:37.820983 oban.1073 > sable.ox.ac.uk.7777: . ack 43448 win 29449
13:25:37.820983 oban.1073 > sable.ox.ac.uk.7777: . ack 43448 win 29449
---------------------------------------------
oban:~$ uname -a
Linux oban 1.3.69 #1 Wed Feb 28 11:34:30 GMT 1996 i586