On Tue, May 15, 2007 at 11:09:03AM -0700, Peter Hessler wrote:
quoted text
> you forgot to enable sysctl net.inet.ip.forwarding=1 on the first test.  
> Turn that on, then re-measure the speeds of the bridge.
> 

bridging is layer 2 and has nothing to do with net.inet.ip.forwarding=1.
The problem is more somewhere deep inside the bridging code. One possible
problem could be a to small interface queue but I could be totaly wrong.
If nobody beats me I will have a look at this somewhen in the next month
or so.

quoted text
> On 2007 May 15 (Tue) at 19:04:47 +0200 (+0200), Renaud Allard wrote:
> :Hello,
> :
> :I just had the opportunity to test some Fluke network equipment, notably
> :one which is able to throughput test gigabit networks.
> :
> :I installed a Nexcom NSA1086 with OpenBSD 4.1-stable and did some tests.
> :The NSA1086 units are equipped with a Pentium IV 3.2Ghz (hyperthreading
> :disabled), and 1Gb ram. They have 4 sk gigabit interfaces, and 4 msk
> :gigabit interfaces. Here are the tests:
> :
> :**********
> :ifconfig sk0 up
> :ifconfig sk1 up
> :ifconfig bridge0 create
> :ifconfig bridge0 up
> :brconfig bridge0 add sk0
> :brconfig bridge0 add sk1
> :sysctl kern.maxclusters=256000
> :
> :Then I connected the fluke analyzers to both sk ports. connections were
> :correctly seen at 1000 base T full Duplex. then I started a throughput
> :test on 1Gbps, and I was extremely surprised to see how performance was
> :very poor. The throughput was only about 77Mbps.
> :
> :***************
> :
> :Seeing that I decided to try on msk interfaces and got about the same
> :"performance".
> :
> :***************
> :
> :Then I configured routing between two interfaces.
> :ifconfig sk2 inet 192.168.0.1 255.255.255.0
> :ifconfig sk3 inet 192.168.1.1 255.255.255.0
> :sysctl net.inet.ip.forwarding=1
> :sysctl kern.maxclusters=256000
> :
> :I did the throughput test, and got about 500Mbps both on sk and msk,
> :with the CPU keeping quiet.
> :
> :**************
> :
> :So the weak performance doesn't seem related to the bus, the CPU, or the
> :sk/msk drivers. Has someone an explanation on why I get this kind of
> :behavior?
> :
> 
> 
> --
> Anthony's Law of Force:
> 	Don't force it; get a larger hammer.
> 

-- 
:wq Claudio