!!!/etc/network/interfaces!!!

auto lo
iface lo inet loopback

auto eth0 eth1
iface eth0 inet dhcp
iface eth1 inet dhcp


!!!ifconfig!!!

eth0      Link encap:Ethernet  HWaddr c0:4a:00:11:86:00
          inet6 addr: fe80::c24a:ff:fe01:8600/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
          Interrupt:66 Base address:0xa000

eth1      Link encap:Ethernet  HWaddr 00:19:dc:51:19:8f
          inet addr:192.168.1.11  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::219:dbff:fe51:198f/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:690 errors:0 dropped:0 overruns:0 frame:0
          TX packets:442 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:63082 (63.0 KB)  TX bytes:56893 (56.8 KB)

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

Notice that Eth1 is connected, but Eth0 is not.

!!!/etc/udev/rules.d/70-persistent-net.rules!!!

# PCI device 0x10ec:/sys/devices/pci0000:00/0000:00:03.0/0000:03:00.0 (r8169)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="c0:4a:00:11:86:00", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

# PCI device 0x1106:/sys/devices/pci0000:00/0000:00:12.0 (via-rhine)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:19:db:51:19:8f", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"


!!!lshw -C network!!!
 *-network
       description: Ethernet interface
       product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: eth0
       version: 06
       serial: c0:4a:00:11:86:00
       size: 100Mbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet phy                                                                                                                                                             sical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8168 driverversio                                                                                                                                                             n=8.038.00-NAPI duplex=full latency=0 link=yes multicast=yes port=twisted pair s                                                                                                                                                             peed=100Mbit/s
       resources: irq:66 ioport:ac00(size=256) memory:dfbff000-dfbfffff memory:d                                                                                                                                                             fefc000-dfefffff
  *-network
       description: Ethernet interface
       product: VT6102 [Rhine-II]
       vendor: VIA Technologies, Inc.
       physical id: 12
       bus info: pci@0000:00:12.0
       logical name: eth1
       version: 7c
       serial: 00:19:db:51:19:8f
       size: 100Mbit/s
       capacity: 100Mbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: pm bus_master cap_list ethernet physical tp mii 10bt 10bt-f                                                                                                                                                             d 100bt 100bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=via-rhine driverve                                                                                                                                                             rsion=1.5.1 duplex=full ip=192.168.1.11 latency=64 link=yes maxlatency=8 mingnt=                                                                                                                                                             3 multicast=yes port=MII speed=100Mbit/s
       resources: irq:23 ioport:d000(size=256) memory:dfffd000-dfffd0ff