mii-tool vs ethtool

both commands are actually doing the same things. an useful tool to display or change ethernet cards settings, but bare in mind that mii-tool only for 10/100M NIC while ethtool can support all hardware. so in case you are using GB cards, you should use ethtool then.

# ethtool eth0
Settings for eth0:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised auto-negotiation: Yes
Speed: 100Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 0
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: umbg
Wake-on: g
Current message level: 0x00000007 (7)
Link detected: yes

for more info

# man ethtool

RX packets errors

still figuring out on why this box having RX packets errors:

# netstat -i
Kernel Interface table
Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg
eth0 1500 0 6562755167 851549 849523 849523 3191554302 0 0 0 BMRU
lo 16436 0 43728443 0 0 0 43728443 0 0 0 LRU

# ifconfig eth0
eth0 Link encap:Ethernet HWaddr 00:11:85:XE:B2:XE
inet addr:XXX.X.XXX.XX Bcast:XXX.X.XXX.XXX Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:6562755167 errors:851549 dropped:849523 overruns:849523 frame:1189
TX packets:3191004809 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:3964758124916 (3781087.9 Mb) TX bytes:336413334315 (320828.7 Mb)
Base address:0x3000 Memory:d6000000-d6020000

or you can see from /proc/net/dev

since this is production server, can't simply reboot to test it out. it could be hardware issue here, maybe switch, cable or the NIC itself or maybe tcp/udp packets. any clue :(