Zdraveite.
Imam 2 LAN karti i dobaviam 3-ta.
Opitah s ifconfig no ne stava.
Eto rezultata:

root@myhost1:~# ifconfig eth2 192.168.0.100/24
SIOCSIFNETMASK: No such device
SIOCSIFADDR: No such device
eth2: unknown interface: No such device
root@myhost1:~# 

Kade mi e problema?
Dali ne e otkrita ot kernela ili e defektna?

Mislia 4e kernel-a ne ia e otkril. Dali sam na veren pat?

Nai-veroiatno ne e zareden modula za kartata ti.
 Napravi /cat/proc/pci  ili lspci, za da proverish kakuv model
 ti e kartata (v sluchai che ne znaesh de ..), posle napravi
modprobe na suotvetniia modul.
S lsmod mozhe da vidish zaredenite veche moduli.

 Ako ne znaesh koi modul ti triabva idi na google i potursi:
linux module <modela na kartata>.

 Ako niamash modula koito ti triabva, shte se nalozhi da si go
kompilirash.

Izglezhda kartata mi e povredena
Eto rezultata
root@myhost1:~# cat /proc/pci
PCI devices found:
  Bus  0, device   0, function  0:
     Host bridge: Acer Laboratories Inc. [ALi] M1541 (rev
4).
      Master Capable.  Latency=64.  
       Non-prefetchable 32 bit memory at 0xe0000000
[0xe3ffffff].
  Bus  0, device   1, function  0:
    PCI bridge: Acer Laboratories Inc. [ALi] M5243 (rev 4).
      Master Capable.  Latency=64.  Min Gnt=8.
  Bus  0, device   3, function  0:
    Bridge: Acer Laboratories Inc. [ALi] M7101 PMU (rev 0).
  Bus  0, device   7, function  0:
     ISA bridge: Acer Laboratories Inc. [ALi] M1533 PCI to
ISA Bridge [Aladdin IV] (rev 195).
  Bus  0, device  10, function  0:
     Ethernet controller: Realtek Semiconductor Co., Ltd.
RTL-8139 (rev 16).
      IRQ 12.
      Master Capable.  Latency=32.  Min Gnt=32.Max Lat=64.
      I/O at 0xd800 [0xd8ff].
       Non-prefetchable 32 bit memory at 0xdb000000
[0xdb0000ff].
  Bus  0, device  11, function  0:
     Ethernet controller: Realtek Semiconductor Co., Ltd.
RTL-8139 (#2) (rev 16).
      IRQ 10.
      Master Capable.  Latency=32.  Min Gnt=32.Max Lat=64.
      I/O at 0xd400 [0xd4ff].
       Non-prefetchable 32 bit memory at 0xda800000
[0xda8000ff].
  Bus  0, device  15, function  0:
     IDE interface: Acer Laboratories Inc. [ALi] M5229 IDE
(rev 193).
      Master Capable.  Latency=32.  Min Gnt=2.Max Lat=4.
      I/O at 0xd000 [0xd00f].
  Bus  1, device   0, function  0:
    VGA compatible controller: S3 Inc. Trio 64 3D (rev 1).
      Master Capable.  Latency=64.  Min Gnt=4.Max Lat=255.
       Non-prefetchable 32 bit memory at 0xdc000000
[0xdfffffff].
root@myhost1:~#
Triabva da ia smenia i togava da sum siguren

 A zashto ti triabvat tolkova LAN karti? Mozhesh na edna da slozhish
poveche ot 1 IP adres.