horiffic network performance

carboncopy · 09-13-2005, 05:14 AM

Slackware-current with 2.6.13.1 on Dell Inspiron 6000

Hardware Specs
Centrino 1.73GHz
1.5 Gbyte of DDR2 533MHz RAM
Broadcom 440 NIC
100Mbitpersecond LAN

Downloading between an (Slackware-current) Apache webserver and the Slackware laptop is at horiffic crawling speed of around 300-400kbytes per second.

I get speeds up to 8Megabyte per seconds downloading with iBook G4 and PowerMac G5 from the same server and same network.

grkellm shows hardly any CPU work. 0-3%

What could be the problem?

hdparm -t /dev/sda give me around 35MB/sec

Zeistler · 09-13-2005, 05:38 AM

There are two kinds of USB-ports. USB 1 and USB 2. USB 2 is alot faster than USB 1. How old is the laptop you have installed Slackware on? Are you sure it supports USB 2?

carboncopy · 09-13-2005, 05:52 AM

Quote:

Originally posted by Zeistler
There are two kinds of USB-ports. USB 1 and USB 2. USB 2 is alot faster than USB 1. How old is the laptop you have installed Slackware on? Are you sure it supports USB 2?

Sorry, the hdparm -t /dev/sda must have mislead you. (The reason I include that in is that harddisk speed might have something to do with it. But it is clear that the harddisk is able to handle far more then the max download speed I am getting.)

It is not about USB harddisk/pendrive. Anyhow the /dev/sda is the internal harddisk. And the laptop is about 1 month old.

My problem is network performance.

Downloading using http and scp is at amazingly LOW speed for a 100Mbps LAN.

carboncopy · 09-13-2005, 06:10 AM

I found a clue.

Code:

eth0      Link encap:Ethernet  HWaddr 00:XX:XX:XX:XX:3E  
          inet addr:10.5.1.8  Bcast:10.5.1.255  Mask:255.255.255.0
          UP BROADCAST NOTRAILERS RUNNING PROMISC MULTICAST  MTU:1500  Metric:1
          RX packets:404545 errors:108248 dropped:40878 overruns:0 frame:0
          TX packets:413148 errors:0 dropped:0 overruns:0 carrier:0
          collisions:123330 txqueuelen:1000 
          RX bytes:502743850 (479.4 Mb)  TX bytes:22328881 (21.2 Mb)
          Interrupt:209

Received error and dropped is VERY HIGH!

Has network settings in the kernel got anything to do with this? Am going to bring the kernel settings down to a minimum for Networking.

tobyl · 09-13-2005, 08:38 AM

I am not an expert on this, but I notice that you are getting a lot of collisions, and that you are in promiscuous mode. What happens when you turn PROMISC off?
As I understand it, promiscuous mode will cause your network connection to accept all packets, including ones not destined for that MAC address, but just happen to be flying around on your network. (Maybe you are running some network analyzing software at the same time to try and figure out what is the problem, as this would account for the promiscuous mode)

just a thought...
tobyl

carboncopy · 09-14-2005, 03:03 AM

Quote:

Originally posted by tobyl
I am not an expert on this, but I notice that you are getting a lot of collisions, and that you are in promiscuous mode. What happens when you turn PROMISC off?
As I understand it, promiscuous mode will cause your network connection to accept all packets, including ones not destined for that MAC address, but just happen to be flying around on your network. (Maybe you are running some network analyzing software at the same time to try and figure out what is the problem, as this would account for the promiscuous mode)

just a thought...
tobyl

Yeah, I was on netwatch when I took the ifconfig.

Situation doesn't improve with netwatch off and PROMISC off.

Anothing thing which I note, I can listen to all the communications using netwatch on this machine. However, I could not do that with my other Slackware machines. Those machines will just listen to their own traffic plus broadcast traffic. However, ethereal can capture all packets on those machines.

Is this something to do with Broadcom driver?

carboncopy · 09-14-2005, 03:06 AM

A few kernel recompiles and now with almost bare minimum networking option still gives me the same problem.

Time to switch cable and/or port to check.

carboncopy · 09-14-2005, 03:08 AM

Quote:

Originally posted by carboncopy
Time to switch cable and/or port to check.

Neither of that help.

carboncopy · 09-14-2005, 03:13 AM

Another clue from /var/log/messages

Code:

Sep 14 16:09:09 madcow kernel: b44: eth0: Link is up at 100 Mbps, half duplex.
Sep 14 16:09:09 madcow kernel: b44: eth0: Flow control is off for TX and off for RX.

Flow control is OFF!!! How do I enable that?

davidsrsb · 09-14-2005, 03:31 AM

And you are also in 100Mb HDX, a very unusual combination unless you really do have a 100Mb hub. Most 100 Mb kit is switched and supports full duplex.
No flow control and half duplex operation is going to give a very high error rate.
What kernel version are you running?

carboncopy · 09-14-2005, 05:53 AM

Yes, it is a 100Mbps hub.

Kernel 2.6.13.1.

Hangdog42 · 09-14-2005, 06:57 AM

You may want to slowly step away from that kernel. I recently tried to upgrade to 2.6.13.1 and it caused all sorts of random problems. Iwlist only worked for normal users, but not for root. Open Office 2 was completely borked. I went back to 2.6.11 and life returned to normal.

Given everything else you've tried, an older kernel version might help. I'm starting to suspect 2.6.13.1 has some issues.

tobyl · 09-14-2005, 08:08 AM

you may find ethtool useful:

you can use it to view or change network card settings. You should be able to change to full duplex etc. (i think functionality varies from nic to nic, but i think broadcom nics are supported)

uselpa · 09-14-2005, 01:43 PM

To me it sounds like a network card problem.
Maybe you could try a LiveCD on the same machine and see if the problem remains.

MMYoung · 09-14-2005, 02:29 PM

Quote:

Originally posted by carboncopy
Downloading between an (Slackware-current) Apache webserver and the Slackware laptop is at horiffic crawling speed of around 300-400kbytes per second.

A little OT, but I never, in my wildest imaginings, EVER thought I'd see the day that 300 to 400 kBps would be considered "horiffic crawling" download speed.

My how things have changed since the 2400 baud modems days!

Good gawd amighty,
MMYoung