Slow network 8139too

Hi All,
I've got a Mandrake 9.1 system on my home network that also
dual-boots to Windows ME. A different computer on the home network,
running Windows ME, is taking care of ICS.
After changing the MTU size on the Windows boot, my network speed (
as reported by www.2wire.com and bos.speakeasy.net ) can reach speeds
of about 1200 kbps.
Changing the MTU on the linux side to the same setting ( 1473 )
doesn't seem to fix the slow network - I still max out at about
300kbps. I have tried numerous other values for MTU, but no luck yet.

The network switch/hub is a Gigafast 500, which claims to do 10/100
baseT at full duplex. mii-tools reports that this is how the network
card is set up ( though I tried all combinations of 10/100 HD/FD to no
avail ).

Does anybody have suggestions for me?

On Thu, 05 Feb 2004 12:08:39 -0800, James Ertle wrote:

> Hi All,
> I've got a Mandrake 9.1 system on my home network that also
> dual-boots to Windows ME. A different computer on the home network,
> running Windows ME, is taking care of ICS.
> After changing the MTU size on the Windows boot, my network speed (
> as reported by www.2wire.com and bos.speakeasy.net ) can reach speeds of
> about 1200 kbps.
> Changing the MTU on the linux side to the same setting ( 1473 )
> doesn't seem to fix the slow network - I still max out at about 300kbps.
> I have tried numerous other values for MTU, but no luck yet.
>
> The network switch/hub is a Gigafast 500, which claims to do 10/100
> baseT at full duplex. mii-tools reports that this is how the network card
> is set up ( though I tried all combinations of 10/100 HD/FD to no avail ).
>
> Does anybody have suggestions for me?

You're talking about some really weird issues here, by coincidence (if
any) i'm using a couple of rtl8139 cards without any issues. They're known
to be problematic at times but to me they're working fine, pretty fast
even.

Changing the MTU indeed can increase bandwith since your standar mtu for
ethernet is 1500 your ethernet frames will be sent more frequently as long
as the link is not saturated. Then it might become slower.

How did you change the mtu on the linux boot ? How did you verify this ?
Did you also change the mtu for the interface the linux-box is connected
to ? No use in changing this if both ends talk different mtu's, might even
decrease your network througput.

You're using a hub/switch ? Pretty strange, either hub or switch ... no ?
If it's a hub it will not ever accept 100-FD since it's distributing it's
traffic to all it's ports all the time, that is a costly hub if it can.
AFAIK some switches can do 100-FD to all channels, my belkin at least can
and it wasn't really expensive so i suppose that goes for you equipment as
well IF it's a switch. But that would only matter if you're connecting to
your ics-machine, this would not matter at all when connecting to the
internet.

Did you try changin the cable on the slow machine ? Or even try a
cross-cable from the linux-box to the ics ?



--
Best Regards,

Dr. Chandra

I'm sorry if I wasn't as clear as I would have liked to be :-) Here
are some clarifications:

The machine that has the problems is a dual-boot machine. When I
boot to Windows ME with a MTU of 1473 ( I chose this because it is the
largest that "ping" reports as not getting fragmented ) I get quite
fast network speeds as reported by www.2wire.com and
bos.speakeasy.net. From this I infer that the hardware and connection
are not the problems.
When I boot to Mandrake 9.1 linux on the other hand, I find that I
get much slower network speeds. I used "ifconfig" to change the MTU
size on linux ( I tried a number of different sizes ), and I used
"mii-tool" to change half/full duplex and 10/100 baseT.

> You're using a hub/switch ? Pretty strange, either hub or switch ... no ?

I put in hub/switch as I wasn't sure which one it was. As I look
at it now, it is a network switch. Its specifications say that it
auto-negotiates and that it is 100baseT.

Here is the output of the "route" command:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref
Use Iface
192.168.0.0 * 255.255.255.0 U 0 0
0 eth0
127.0.0.0 * 255.0.0.0 U 0 0
0 lo
default 192.168.0.1 0.0.0.0 UG 0 0
0 eth0



Thanks for your help!

JimE.