/etc/udev/rules.d/70-persistant-net

# PCI device 0x11ab:0x4362 (sky2)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:15:f2:1b:12:98", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"
 
# PCI device 0x10ec:0x8139 (8139too)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:50:fc:08:95:41", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"

using iref

iperf -s
iperf -c <server name>

$ sudo ethtool eth0
Settings for eth0:
	Supported ports: [ TP ]
	Supported link modes:   10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Half 1000baseT/Full 
	Supports auto-negotiation: Yes
	Advertised link modes:  10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Half 1000baseT/Full 
	Advertised auto-negotiation: Yes
	Speed: 100Mb/s
	Duplex: Full
	Port: Twisted Pair
	PHYAD: 0
	Transceiver: internal
	Auto-negotiation: on
	Supports Wake-on: pg
	Wake-on: d
	Current message level: 0x000000ff (255)
	Link detected: yes
$ ethtool -s eth0 speed 1000 duplex full

• gigabit crosscable