LARTC - Apr 2002 - IMQ & HTB problem

Hi everybody,

I have a strange problem. I recently found IMQ dummy device and I was 
anxious to test this on my router. I have the following configuration:

iptables -t mangle -A PREROUTING -i eth0 -m mark --mark 0 -d $MY_NET -j 
IMQ --todev 0
iptables -t mangle -A POSTROUTING -o eth0 -m mark --mark 0 -s $MY_NET -j 
IMQ --todev 1

insmod imq

tc qdisc add dev imq0 root handle 1: htb default fff
tc qdisc add dev imq1 root handle 1: htb default fff

tc class add dev imq0 parent 1:0 classid 1:1 htb rate 192Kbit
...

tc filter add dev imq0 parent 1:0 protocol ip prio 100 u32 match ip src...
bla bla bla

ip link set imq0 up; ip link set imq1 up

The problem is that when I run this script, those packets that are 
routed via imq* (0 for in and 1 for out) are slowed down to ridiculous 
speeds (1kbit or less for a 64kbit class for eg.)

I read about some bugs that lies in IMQ code but I also read about 
crashes related to this bugs and this is not my case.

Could anyone help me pls? I must finish this script till monday. Could 
it be usage of u32 filters? But still I see that packets are getting to 
the right classes.

Thanks,
Alin Nastac

Hi !

Alin Nastac wrote:
> Hi everybody,
> 
> I have a strange problem. I recently found IMQ dummy device and I was 
> anxious to test this on my router. I have the following configuration:
> 
> iptables -t mangle -A PREROUTING -i eth0 -m mark --mark 0 -d $MY_NET -j 
> IMQ --todev 0
> iptables -t mangle -A POSTROUTING -o eth0 -m mark --mark 0 -s $MY_NET -j 
> IMQ --todev 1
> 
> insmod imq
> 
> tc qdisc add dev imq0 root handle 1: htb default fff
> tc qdisc add dev imq1 root handle 1: htb default fff
> 
> tc class add dev imq0 parent 1:0 classid 1:1 htb rate 192Kbit
> ...
> 
> tc filter add dev imq0 parent 1:0 protocol ip prio 100 u32 match ip src...
> bla bla bla
> 
> ip link set imq0 up; ip link set imq1 up
> 
> The problem is that when I run this script, those packets that are 
> routed via imq* (0 for in and 1 for out) are slowed down to ridiculous 
> speeds (1kbit or less for a 64kbit class for eg.)
In fact, packets aren''t routed via imq but only enqueued/dequeued to
the
attached qdiscs. Please post your entire script because the error is 
most probably in there..
> I read about some bugs that lies in IMQ code but I also read about 
> crashes related to this bugs and this is not my case.
Glad to here that, although the bug is still present .. i haven''t found
the time to debug it but i''ll probably get to it this week.

Bye,
Patrick