I am having some trouble with an NFS server that I made. when I was sending it information, and try to take information off it at the same time it usually kills off both transfers. also it is running really slowly, so I am thinking it is a duplex mismatch. I was wondering how to check the status of the ethernet cards to find if they were on full or half duplex, and how to change them.

the NFS server is running Fedora Core 3
and the other computer is running SuSE 9.1?
and they are connected through a switch

thank you.

try using mii-tool to prod and poke a network card.

thank mii-tool is giving me this output on the SuSE box

SIOCGMIIPHY on 'eth0' failed: Operation not supported
no MII interfaces found

but mii-diag seems to give useful output, saying:

The autonegotiated capability is 01e0.
The autonegotiated media type is 100baseTx-FD.
Basic mode control register 0x1100: Auto-negotiation enabled.
You have link beat, and everything is working OK.
Your link partner advertised 45e1: Flow-control 100baseTx-FD 100baseTx 10baseT- FD 10baseT, w/ 802.3X flow control.
End of basic transceiver information.

and the mii-tool on the fedora core machine outputs:

eth0: negotiated 100baseTx-FD, link ok

so I think they are on the same status, so I guess that would remove the duplex settings as the problem? and thank you very much for your help.

try ethtool as a root. ethtool ethx would give you detailed information about the eth card. you can change to full duplex, if your card support it, using the ethtool.
check ethtool help or man to know more.
ethtool -s ethX [speed 10|100|1000] [duplex half|full]

thats an interesting command, it showed me everything that I wanted to know, unfortunatly I don't see the problem with the output. I got this as output on both computers:

[root@NFSserver michael]# /sbin/ethtool eth0
Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Advertised auto-negotiation: Yes
Speed: 100Mb/s
Duplex: Full
Port: MII
PHYAD: 32
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: pumbg
Wake-on: d
Current message level: 0x00000007 (7)
Link detected: yes

so as far as I can tell both computers should have been getting along, it seemed like the transfer rate was only a megabyte a second or so (and that the connections would be lost if I tried to upload and download at the same time to/from the NFS), which would mean that something is wrong, but I don't know what it would be.

and thank you for your help.