Subject: more ratelimit issue
To: None <tech-net@netbsd.org>
From: None <itojun@iijlab.net>
List: tech-net
Date: 07/26/2000 18:12:26
please see PR 9978 about TCP behavior change due to RST rate limitation.
There are multiple ways to address this problem:
- disable RST rate limitation for local packets, like we did for
IPv4 ICMP error rate lmitation.
- do not use ratelimit(9), use ppsratelimit(9). ratelimit does not
work right for smaller-than-1/hz limitation.
- do not do rate limitation at all.
- use more clever algorithm for rate limitation
the last one should need longer research, should be post 1.5 item.
I believe the right way (quick solution for 1.5) is the second one.
we cannot really trust local traffic (local traffic does not fill
network bandwidth, however, it still chews CPU time) so the first
one will be ruled out. Is it okay if I make the following changes:
- tcp_input to use ppsratelimit(9), instead of ratelimit(9)
and also,
- remove "loopback is okay" code from IPv4 ICMP error rate limitation.
itojun