lot of Rx packet errors

HI
i'm haveing troubles with my network. Here are some infos:

ifconfig:

eth0 Link encap:Ethernet HWaddr 00:C0F:EAB:F7
inet addr:62.21.40.142 Bcast:62.21.47.255
Mask:255.255.240.0
inet6 addr: fe80::2c0:dfff:feea:dbf7/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:9047 errors:0 dropped:0 overruns:0 frame:0
TX packets:8092 errors:0 dropped:0 overruns:0 carrier:0
collisions:1 txqueuelen:1000
RX bytes:4063534 (3.8 MiB) TX bytes:1190690 (1.1 MiB)
Interrupt:11 Base address:0x6200

eth1 Link encap:Ethernet HWaddr 00:50:04:82:110
inet addr:192.168.0.1 Bcast:192.168.0.255
Mask:255.255.255.0
inet6 addr: fe80::250:4ff:fe82:11d0/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:22992 errors:897 dropped:0 overruns:0 frame:908
TX packets:28676 errors:0 dropped:0 overruns:0 carrier:2
collisions:0 txqueuelen:1000
RX bytes:7346616 (7.0 MiB) TX bytes:17211233 (16.4 MiB)
Interrupt:10 Base address:0x6300

dmesg:

eth0: RealTek RTL-8029 found at 0x6200, IRQ 11, 00:C0F:EAB:F7.
3c59x: Donald Becker and others. www.scyld.com/network/vortex.html
0000:00:09.0: 3Com PCI 3c980 Cyclone at 0x6300. Vers LK1.1.19

OS is Debian 3.1, eth0 is external interface, and eth1 is the trouble
one, connected to the switch. Transferring between this box and another
is very slow.

I'm wondering what is the problem, software or hardware?
and how to diagnose it?

thx !!