Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 16 May 2001 08:36:24 +0200 (CEST)
From:      Luigi Rizzo <luigi@info.iet.unipi.it>
To:        "Patrick O'Reilly" <patrick@mip.co.za>
Cc:        ipfw@FreeBSD.ORG, Holtor <holtor@yahoo.com>, questions@FreeBSD.ORG
Subject:   Re: Bandwidth Limiting per IP
Message-ID:  <200105160636.IAA44066@info.iet.unipi.it>
In-Reply-To: <NDBBIMKICMDGDMNOOCAICEOGCHAA.patrick@mip.co.za> from "Patrick O'Reilly" at "May 16, 2001 08:29:46 am"

next in thread | previous in thread | raw e-mail | index | archive | help
> There is additional overhead in processing so many pipes, but if the box in

actually, if you use dynamic pipes e.g.

	ipfw add pipe 1 ip from 10.1.2.0/24 to any
	ipfw pipe 1 config bw 100Kbit/s mask src-ip 0x000000ff

then everything works pretty fast -- the ruleset is short, and
the pipe processing overhead is O(log n) where n is the number of
_active_ pipes.

In cases like these i would also suggest the use of fair queueing,
which works well in 4.3

	ipfw add queue 1 ip from 10.1.2.0/24 to any
	ipfw pipe 10 config bw 2Mbit/s
	ipfw queue 1 config pipe 1 weight 30 mask src-ip 0x000000ff

so all active flows get an equal share of the total capacity.

> question is doing nothing other than acting as a gateway/router then I doubt
> that this will be a real problem.  I have a vague memory that someone once
> benchmarked a set if ipfw rules and found that with a set of 1000 rules (the
> average search would therefore hit at about rule 500) the actual latency
> induced was just a few milliseconds.

yep -- but the 'mask' mechanism often saves you from using so many rules.

	cheers
	luigi
-----------------------------------+-------------------------------------
  Luigi RIZZO, luigi@iet.unipi.it  . Dip. di Ing. dell'Informazione
  http://www.iet.unipi.it/~luigi/  . Universita` di Pisa
  TEL/FAX: +39-050-568.533/522     . via Diotisalvi 2, 56126 PISA (Italy)
  Mobile   +39-347-0373137
-----------------------------------+-------------------------------------

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-ipfw" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200105160636.IAA44066>