Re: [gentoo-user] Rate limiting TCP connections...

[Norberto Bensa]

Quoting gentoo_steve@×××××××.uk:

> Norberto Bensa wrote:
>> Ah!! But Windows (XP) uses TC by default. It doesn't use 20% of the
>>  network bandwidth unless you tweak some registry setting and/or
>> disable QoS in network properties.
> That sounds like a fine plan for me...

which one? remove qos from windows? nope. that would just overload  
your router.

> but, erm, how does it know? Both
> Linux and Xp talk to my router at 100mbps - and my router talks to the
> outside world at 0.5mbps...

That's the problem. It's common, don't worry. You just need to control  
how much and in which order packages are delivered to your router so  
it doesn't have to decide how to route traffic (its queue is not that  
intelligent.) It's all explained in "latrc" which I recommend you to  
read.


> so, while I'd be entirely happy to cap both
> machines at 80mbps, I don't see why this would have any effect on the
> competition for the 0.5mbps to the outside world.

Yes. My iptables example was toooooo aggresive, I know. It was just an  
example. You can modify it like this:

   iptables -I INPUT -i lo -j ACCEPT
   iptables -I INPUT -s 192.168.0.0/24 -j ACCEPT
   iptables -I INPUT -p tcp -m limit --limit 50/sec -j ACCEPT
   iptables -I INPUT -p tcp -j DROP

The first one takes care of localhost. You don't want to limit traffic  
on that interface :)

The seccond one permits everything from the local network (change  
192.168.0.0/24 for the rights values for your local/home network)

Third and fourth are the same rules I posted before.

With those rules you'll get full speed on the local network and 50  
packets per second on everything else (internet.)


> What's more to the point, it doesn't seem to be Linux competing with
> Xp, per se - but rather Linux competing with Linux - since my LAN works
> great - and I can communicate at will between Xp and Linux - it is only
> when Linux's bind competes with Linux's wget that I see a problem.
> This is with two processes on the same PC.

wget and bind compete for internet access. wget is eating all the  
bandwidth and bind doesn't have a chance. Do you have "forward first"  
in named.conf? If it is, comment it; it will help a bit.


>> try a --limit-rate (or --rate-limit; I can't never get  it right) in wget.
> I presume this is what you mean (taken from "man iptables"):

nope. wget's --limit-rate.


> This looks as if I can limit the rate at which my linux box talks on my
> LAN - but this isn't what I need to do. Interestingly, long downloads
> from two competing WinXp boxes don't cause a problem - but both will
> max-out my available download capacity... suggesting to me that fixed
> rate-limiting is not what is called for...

Nope. "fixed rate limiting" is not the answer. You need QoS at the  
router level, but if it doesn't support it, you'll need to change how  
your Linux box talks and listen to internet packages. That's what I  
said -more or less- on my first reply.

Let's make an experiment:

1. Terminate all downloads and activity on the internet.
2. Restart your bind (so it flushes its cache)
3. in XP1 download something huge (an ISO image) from one souce in the  
internet and wait 'til it is at full speed (does it go up to 0.5Mb??)
4. in XP2 start to ping different sources. Does XP2 lost packets?

Regards,
Norberto

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