Re: HFSC

Lawrence MacIntyre
Thu, 13 May 2004 17:43:36 -0000

Patrick:

I tried that filter line, but it has incorrect syntax.  But that isn''t
the problem.  The problem is the HFSC part...  The traffic is indeed UDP
port 1234, and the HFSC qdisc functions for a short period of time
(between 5 and 60 seconds or so, and then stops passing any traffic on
the eth0 interface.  You can look with ethereal, and the interface is
totally silent.  Even weirder, if you wait, periodically (every several
minutes or so) you get another period of working.  These are typically
5-10 seconds.  What do I need to do to debug this?  The machine is a
dual Xeon, if that matters.

Patrick McHardy wrote:
> Lawrence MacIntyre wrote:
>
>> Thanks, Patrick.  That makes it a bit harder to manage from a remote
>> machine.  I''ll have to be very careful with that.
I''ll try to figure
>> out the implications of the default classification and send more email
>> if I can''t get it.
>>
>> So I reordered the commands and changed them around.  It looks like I
>> am either doing something strange or I have found a bug.  When I
>> execute the following script, the UDP traffic on port 1234 continues
>> for a few seconds and then stops.  When I examine the tc data, it
>> shows no change in the periods or amount of bytes flowing after the
>> flow stops.  I am enclosing the command  and the output.
>
>
> It is indeed strange. Only the qdisc drop counter is incremented, which
> means the packets are still unclassified. What happens if you change
> your filter to:
>
> /usr/local/bin/tc filter add dev eth0 protocol ip parent 1:0 prio 1 u32
> match udp dport 1234 0xffff flowid 1:10 (match udp instead of ip)
>
> Are you sure the packets are sent to port 1234 ?
>
> Regards
> Patrick