Re: [PATCH] doc: document danger of applying REJECT to INVALID CTs

2020-05-09 Thread Maciej Żenczykowski
Also maybe the example should be: instead of just: -A INPUT ... -j REJECT do: -A INPUT ... -m conntrack --ctstate INVALID -j DROP -A INPUT ... -j REJECT

Re: [PATCH] doc: document danger of applying REJECT to INVALID CTs

2020-05-09 Thread Maciej Żenczykowski
I *think* that your talk of 3 packets is not needed, ie. the initial delayed packet doesn't have to be a retransmission. It can be the first copy of that segment that gets massively delayed and arrives late and causes problems, by virtue of arriving after the retransmission already caused the conne

[PATCH] doc: document danger of applying REJECT to INVALID CTs

2020-05-09 Thread Jan Engelhardt
Signed-off-by: Jan Engelhardt --- Maciej's explanation on how INVALID+REJECT can lead to problems looks convincing. I hereby present new manpage wording in the form of "if A, then B" to better build the argument of avoiding REJECT. So the issue is not caused by an _incoming_ TCP RST as the initia