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Re: gigabit ethernet?



> > > 
> > >   
> > I have half a dozen D-Link System Inc DGE-530T Gigabit Ethernet
> > Adapter (rev 11) running in standard PCs (32bit Intel) with Redhat
> > Server and F8, Fast Ethernet or GBit depending on the switches (no
> > VLAN or fancy stuff). No problem there.
> 
> We've pretty much standardized on Intel or Broadcom cards.  The drivers
> are pretty bulletproof and they support all the bizarro stuff like
> jumbo frames, QoS, VLAN (802.1q), trunking and the like.
> 
Slightly OT but ...

Having install one of my 2 DGE-530Ts I am trying to talk to a machine with
a built in GBit NIC based on the Broadcom 5789 chip.
It works perfectly with mtu 1500 - different performance depending which
iperf is a "server"
naxos has DGE-530T
fuerte has built in BCM5789

[root fuerte net]# iperf -c naxos
------------------------------------------------------------
Client connecting to naxos, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[  3] local 148.197.29.246 port 57748 connected with 148.197.29.242 port 5001
[  3]  0.0-10.0 sec    420 MBytes    352 Mbits/sec
-------------------------------------
-------------------------------------
[root naxos ~]# iperf -c fuerte
------------------------------------------------------------
Client connecting to fuerte, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[  3] local 148.197.29.242 port 38347 connected with 148.197.29.246 port 5001
[  3]  0.0-10.0 sec    705 MBytes    591 Mbits/sec
#######################################################################
lspci
02:00.0 Ethernet controller: Broadcom Corporation NetLink BCM5789 Gigabit Ethernet PCI Express (rev 21)
-------------------------------------
This is a fully updated F8 machine and the "NIC" uses 
[root fuerte ~]# ethtool -i eth0
driver: tg3
version: 3.81
firmware-version: 5789-v3.29a
bus-info: 0000:02:00.0
-------------------------
The built in BCM5789 fails to set the mtu greater than 1500 !!!!!!!!
(The DGE-530T will set mtu 9000 OK)

[root fuerte ~]# ifconfig eth0 mtu 9000
SIOCSIFMTU: Invalid argument
-------------------------------------
[root fuerte ~]# ifconfig eth0 mtu 1499
[root fuerte ~]# ifconfig eth0 mtu 1501
SIOCSIFMTU: Invalid argument
[root fuerte ~]# ifconfig eth0 mtu 1500
[root fuerte ~]#
-------------------------------------
I have down loaded the kernel src and had a look at the tg3 driver
/root/rpmbuild/BUILD/kernel-2.6.23/linux-2.6.23.x86_64/drivers/net/tg3.c

/* hardware minimum and maximum for a single frame's data payload */
#define TG3_MIN_MTU                     60
#define TG3_MAX_MTU(tp) \
        ((tp->tg3_flags2 & TG3_FLG2_JUMBO_CAPABLE) ? 9000 : 1500)

I have been to the Broadcom site and down loaded the latest driver
tg3-3.81c-1.src.rpm and the tar version
tg3-3.81c.tar.gz
I have failed miserably to rpmbuild or make either version !!
I can give full details if someone can help.

So what am I asking ?????

1. Is the performance as expected ?
2. Is faster one way than the other normal when using iperf ?
3. Is it possible that even though the chip supports jumbo frames
   the implementation on the board does not ?
4. Is using jumbo frames worth the effort ?

My next move is to install a 2nd  DGE-530T on fuerte

Then I can justify hijacking the thread !!!!

John







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