Heho, Quick follow-up; Applied the change you suggested, but there are still some things to test.
While this now works (mostly), MSS values are still off; Especially the behavior below <=1036 is difficult, as for v4 the minimum MTU is 576 and minimum MSS is 536: Requested DPRINT 1320 1292 1319 1291 1100 1024 1036 1024 1035 271 1000 268 So, I guess there is something else amiss; Will test more in-depth later tonight and shift the bits a bit; Also, I will look into behavior when forcing >1500 MTUs (in case that works with the rtl8139). Sidenote: This all seems to be a non-issue for v6, as the RTL8139 does not support TSO for v6, so at least one thing less to worry about. ;-) With best regards, Tobias