dns cache beyond ttl - viasat / exede

Brielle bruns at 2mbit.com
Mon Oct 7 18:56:26 UTC 2019


On 10/7/2019 12:15 PM, William Herrin wrote:
> On Mon, Oct 7, 2019 at 10:13 AM Brielle <bruns at 2mbit.com 
> <mailto:bruns at 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



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