limiting bandwith

[Ludo Koren]

Hi.

I am running ipfw on 5.2.1-RELEASE-p1.

The relevant part of the ipfw configuration follows:

add check-state
pipe 10 config bw 64Kbit/s
pipe 20 config bw 256Kbit/s
pipe 30 config bw 8Kbit/s
queue 10 config pipe 10 weight 100
queue 20 config pipe 20 weight 1
queue 30 config pipe 30 weight 1
....

# Allow SMTP
add pass tcp from A to B 25 keep-state
add pass tcp from B to A dst-port 25 in via xl0
add pass tcp from A 25 to B in recv xl1
add pipe 20 tcp from B to A dst-port 25 out xmit xl1 keep-state
add pass tcp from C to B 25 keep-state
add pass tcp from B to C dst-port 25 in via xl0
add pass tcp from C 25 to B in recv xl1
add pipe 20 tcp from B to C dst-port 25 out xmit xl1 keep-state

where the A,B,C addresses are not assigned to local interfaces. The
xl0 is on the local LAN, the xl1 is connected to the router and
WAN. If I watch packets (netstat -w 10 -I xl1) flowing through xl1, I
see numbers are correct (~32000 bytes per second). MRTG on the router
shows just half throughput, i.e. 128Kb/s. If I reconfigure pipe 20 to
512Kbit/s or 0Kbit/s, the MRTG shows 256Kbit/s.

Could you point to me what I did wrong?

Thank you very much in advance.

lk