On 10/7/2019 12:15 PM, William Herrin wrote:
On Mon, Oct 7, 2019 at 10:13 AM Brielle <bruns@2mbit.com <mailto:bruns@2mbit.com>> wrote:
* Responding to three way handshake before the other end actually does (nmap -sT remote host ends up with every port being 'open' but closing connection right away)
This is the action of the TCP accelerator. TCP has a "long fat pipe" problem where high-delay links (like a trip to geostationary orbit and back) demolish throughput. To combat this, satellite protocols translate TCP flows to a non-TCP or modified TCP protocol for transmission through the satellite and then back to TCP in the modem.
Yeah, its just one of those things that really messes with you when you are trying to diagnose obscure error messages and application behavior. Usually I'd be in a place 50+ miles from nearest town with cell service, only accessible via jetboat... stuck on Iridium sat phone at $5/min with the Sat company, their utterly useless first level support that refuses to actually get a network engineer involved... I'm a patient, tolerant woman normally with tech support, but the sat internet providers push you into a red zone so quickly with their support... -- Brielle Bruns The Summit Open Source Development Group http://www.sosdg.org / http://www.ahbl.org