LARTC - Apr 2002 - Linux CBQ question

Hi,

Question on Linux-CBQ. I have a Pentium 4 based PC running Redhat 7.2 (kernel
2.4.7) with 2 100-Base T ethernet interfaces (Eth0, Eth1). Traffic received
on Eth0 is sent out on Eth1.

I am trying to restrict the outgoing traffic rate on Eth1 to 50Mbits/sec.
However, when I use the configuration below, I find that the rate on Eth1
is about 5 Mbits/sec. If I delete the keywords bounded, isolated, I get
a rate of 90 Mbits/sec. Measurements were made over an interval of 15 sec
to 1 min)

On trying other Minburst, Maxburst values, the rate changes (e.g. Maxburst
= 300, Minburst = 70) produces 25Mbits/sec etc.

(I was trying to create a hierarchy of classes whose total rate needs to
be limited to 50Mbits/sec, I have managed to reduce the problem from that
to this simplified configuration. I would prefer not to use HTB at the moment).

Can someone take a quick look at the configuration below and tell me what
I am doing wrong? (Ip address of Eth0=10.1.1.2, netmask=255.255.255.0;
Eth1=10.1.2.2,netmask=255.255.255.0)

Thanks

Udayan

------------------

#!/bin/sh

sysctl -w net.ipv4.ip_forward=1

arp -s 10.1.2.4 00:80:AD:55:44:33

tc qdisc add dev eth1 root handle 1:0 cbq avpkt 1000 bandwidth 100Mbit mpu
64

tc class add dev eth1 parent 1:0 classid 1:1 cbq avpkt 1000 bandwidth 100Mbit
cell 8 maxburst 5 minburst 1 minidle 10 mpu 64 rate 50Mbit allot 1500 prio
1 weight 5Mbit bounded isolated

tc qdisc add dev eth1 parent 1:1 bfifo limit 200000

tc filter add dev eth1 parent 1:0 protocol ip prio 1 u32 match ip dst
10.1.2.4/32
flowid 1:1

On Tuesday 30 April 2002 23:38, Udayan Borkar wrote:
> Hi,
>
> Question on Linux-CBQ. I have a Pentium 4 based PC running Redhat 7.2
> (kernel 2.4.7) with 2 100-Base T ethernet interfaces (Eth0, Eth1). Traffic
> received on Eth0 is sent out on Eth1.
>
> I am trying to restrict the outgoing traffic rate on Eth1 to 50Mbits/sec.
> However, when I use the configuration below, I find that the rate on Eth1
> is about 5 Mbits/sec. If I delete the keywords bounded, isolated, I get
> a rate of 90 Mbits/sec. Measurements were made over an interval of 15 sec
> to 1 min)
>
> On trying other Minburst, Maxburst values, the rate changes (e.g. Maxburst
> = 300, Minburst = 70) produces 25Mbits/sec etc.
>
> (I was trying to create a hierarchy of classes whose total rate needs to
> be limited to 50Mbits/sec, I have managed to reduce the problem from that
> to this simplified configuration. I would prefer not to use HTB at the
> moment).
You can do it also with CBQ.  But you have to be carefull by choosing the 
parameters.
> Can someone take a quick look at the configuration below and tell me what
> I am doing wrong? (Ip address of Eth0=10.1.1.2, netmask=255.255.255.0;
> Eth1=10.1.2.2,netmask=255.255.255.0)
The commands seems ok to me.  I tried to bound the outgoing traffic on a 
10mbit card and I had some good results 
(http://www.docum.org/stef.coene/qos/tests/cbq/bounded/bounded.html).  But I 
also found that the isolated parameter is not working and can distrub the 
setup.  So, can you try again with only the bounded and no isolated parameter 
?

Stef

-- 

stef.coene@docum.org
 "Using Linux as bandwidth manager"
     http://www.docum.org/
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