[Ecn-sane] what does ecnseen really mean?

[Ecn-sane] what does ecnseen really mean?

[Dave Taht]

from a random box with bbr on and tons of connections.

```
% sysctl -a | fgrep ecn
net.ipv4.tcp_ecn = 2
net.ipv4.tcp_ecn_fallback = 1

% ss -antie 'src x.y/16' | fgrep bbr | fgrep -c ecn
524

% ss -antie 'src x.y/16' | fgrep bbr | fgrep -c ecnseen
484

% ss -antie 'src x.y/16' | fgrep bbr | wc -l
22037
```



-- 
"For a successful technology, reality must take precedence over public
relations, for Mother Nature cannot be fooled" - Richard Feynman

dave@taht.net <Dave Täht> CTO, TekLibre, LLC Tel: 1-831-435-0729

Re: [Ecn-sane] what does ecnseen really mean?

[Jeremy Harris]

On 13/01/2021 04:48, Dave Taht wrote:
> from a random box with bbr on and tons of connections.
> 
> ```
> % sysctl -a | fgrep ecn
> net.ipv4.tcp_ecn = 2
> net.ipv4.tcp_ecn_fallback = 1
> 
> % ss -antie 'src x.y/16' | fgrep bbr | fgrep -c ecn
> 524

             ecn    show string "ecn" if the explicit congestion notification option is set


> 
> % ss -antie 'src x.y/16' | fgrep bbr | fgrep -c ecnseen
> 484

               ecnseen
                      show string "ecnseen" if the saw ecn flag is found in received packets


> 
> % ss -antie 'src x.y/16' | fgrep bbr | wc -l
> 22037
> ```
> 
> 
> 


-- 
Cheers,
   Jeremy