link drops dead now and then

Fri Mar 26 13:42:25 1999

Sometimes especially when copying large files via samba (to or from a
win95 machine, which does work OK with an NT server which was on the
same machine that now has linux and samba) but not exclusively
(sometimes also when using ftp) the link drops dead. The traffic LED on
the NIC stops flashing and after a while the application(s) complain
that the link or network resource has gone. 

I do use an Asus P2B-S mainboard flashed with the latest BIOS (v.1008),
with 128 M RAM and a 9.1 GB SCSI u2w HDD. I use kernel 2.0.36 with

Network firewalls
TCP/IP networking
forwarding / gatewaying
syn cookies
IP firewalling
firewall packet logging
masquerading
ICMP masquerading
always defragment
drop source routed frames
allow large windows

enabled.

This machine will be used to give a small office internet connectivity
(in addition to file and printer sharing (hence samba). With
masquerading I can use an ordinary one IP address account with my ISP.

The client is a Asus TX97 mainb PC with 64 MB RAM and the same SMC
Etherpower NIC.

They are linked by a cross-cable

These are some logs from the server:

1) Copy to windows machine (with also EPII NIC via crosscable) via smbd
(very slow looks like a 10 Mbps link though all leds are lit on both
NIC's indicating 100Mbps)

Basic registers of MII PHY #3:  3000 782d 0181 4401 01e1 41e1 0001 ffff.
 Basic mode control register 0x3000: Auto-negotiation enabled.
 You have link beat, and everything is working OK.
 Your link partner can do 41e1: 100baseTx-FD 100baseTx 10baseT-FD
10baseT.

2) When copying the same file with WS_FTP on the Win95 machine 
from the linux server. Much faster 3.5 MBytes / s

Basic registers of MII PHY #3:  3000 782d 0181 4401 01e1 41e1 0001 ffff.
 Basic mode control register 0x3000: Auto-negotiation enabled.
 You have link beat, and everything is working OK.
 Your link partner can do 41e1: 100baseTx-FD 100baseTx 10baseT-FD
10baseT.

3) Windows copying file from linux samba server, same as 1. Now it stops 
halfway. Windows says cannot copy <filename>: the specified network
resource is no longer available: 

Basic registers of MII PHY #3:  3000 7829 0181 4401 01e1 41e1 0003 ffff.
 Basic mode control register 0x3000: Auto-negotiation enabled.
 Basic mode status register 0x7829 ... 782d.
   Link status: previously broken, but now reestablished.
 Your link partner can do 41e1: 100baseTx-FD 100baseTx 10baseT-FD
10baseT.

4) Copying the file from the Win95 machine to the Linux Samba server.
Now this goes fast. Yesterday this went slow and copying in the other
direction was much slower...

Basic registers of MII PHY #3:  3000 782d 0181 4401 01e1 41e1 0001 ffff.
 Basic mode control register 0x3000: Auto-negotiation enabled.
 You have link beat, and everything is working OK.
 Your link partner can do 41e1: 100baseTx-FD 100baseTx 10baseT-FD
10baseT.

After all this activity:

eth0      Link encap:Ethernet  HWaddr 00:E0:29:1F:3D:BE  
          inet addr:192.168.0.10  Bcast:192.168.0.255 
Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:210247 errors:0 dropped:0 overruns:0 frame:0
          TX packets:303848 errors:0 dropped:0 overruns:0 carrier:0
          Collisions:0 
          Interrupt:10 Base address:0xb800 

Powered down both machines. Took them off the cross cable, put
them on a standard 10 Mbps hub. The LEDs on the NIC's indicate a 
10 Mbps link.

5) Copying a file from the samba server to the windows client: