ipfw bandwidth shaping problems (intermittent latency)

[Andy Coates]

clemens fischer (ino-qc at spotteswoode.de.eu.org) wrote:
> * Andy Coates:
> 
> > 64 bytes from x.x.x.x: icmp_seq=0 ttl=248 time=70.803 ms
> > 64 bytes from x.x.x.x: icmp_seq=1 ttl=248 time=3.850 ms
> > 64 bytes from x.x.x.x: icmp_seq=2 ttl=248 time=3.551 ms
> > 64 bytes from x.x.x.x: icmp_seq=3 ttl=248 time=123.844 ms
> 
> what type of network-card do you have installed?  some people claim
> that this can be an issue with the card, although i don't believe this
> having tried a couple.
> 
> PING (some external host): 56 data bytes
> 64 bytes from x1.x2.x3.x4: icmp_seq=0 ttl=246 time=74.959 ms
[snip]

The card is onboard (its an IBM netfinity 400R 1U high rackable type),
but uses the FXP driver:

fxp0 at pci0:17:0:	class=0x020000 card=0x105c1014 chip=0x12298086 rev=0x08 hdr=0x00
    vendor   = 'Intel Corporation'
    device   = '82557/8/9 EtherExpress PRO/100(B) Ethernet Adapter'
    class    = network
    subclass = ethernet

Also, if I remove all limiting (bw 0), there is no problem - so I wouldn't
say its a hardware fault.  Just when the limiting is applied...

Cheers,
Andy.