I just moved into a dorm at college. I initially plugged my laptop into the network and it got an IP address fine and everything worked. Then I plugged my desktop in. A few boot-ups of my laptop later, it refused to get an IP address. I ran dmesg | tail and got the following:
Code:
eth0: no link during initialization
ADDRCONF(NETDEV_UP): eth0: link is not ready
if I run ifup eth0 it outputs:
Code:
Ignoring unknown interface eth0=eth0
I saw somewhere that restarting the forcedeth module could help. It did in the beginning (two times) but since then I've re-installed Ubuntu 8.04 and it makes no difference now.

Even weirder, for a while, if I would unplug my desktop computer's ethernet cable and then plug in my laptop, the laptop would instantly get an address. Then I could plug back in my desktop and all would be well until I restarted the laptop and I would have to repeat the process. Now, not even that works!

Then I was going to make sure it just wasn't my room that was causing the problem so I went next door. I plugged in my laptop and the network worked instantly. I went to the library and the wireless works as well (just for reference, I know this probably makes no difference). So essentially the problem only happens in my room on wired networking - unfortunately this is 99% of my usage.

I suspect ADDR_CONF could mean address conflict(?), but at one point, I set eth0 as a static address in my /etc/interfaces, the same IP address as my desktop, and when the desktop was unplugged, the network worked (as I stated before) and then I could plug in the desktop again - but the desktop was fine, so obviously the network didn't mind. This is the weirdest most inconsistent problem I've ever encountered on Ubuntu.

The networking even fails if I boot from the live CD. So then I tried an old Slax live CD and the networking didn't work on there either!

But it connects instantly in Windows XP!

The LEDs on the network card are all off, unless I start in Windows or turn the computer off.

Then after leaving the laptop alone for a few days I plugged it back in and the network card turned on and dmesg | tail reported
Code:
eth0: link up
ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
NET: Registered protocol family 17
eth0: no IPv6 routers present
But after a restart, it has reverted to
Code:
ADDRCONF(NETDEV_UP): eth0: link is not ready
below is my lspci -vv
Code:
00:00.0 RAM memory: nVidia Corporation C51 Host Bridge (rev a2)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0
	Capabilities: <access denied>

00:00.1 RAM memory: nVidia Corporation C51 Memory Controller 0 (rev a2)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B-
	Status: Cap- 66MHz+ UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR+ <PERR-

00:00.2 RAM memory: nVidia Corporation C51 Memory Controller 1 (rev a2)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap- 66MHz+ UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-

00:00.3 RAM memory: nVidia Corporation C51 Memory Controller 5 (rev a2)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap- 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-

00:00.4 RAM memory: nVidia Corporation C51 Memory Controller 4 (rev a2)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap- 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0

00:00.5 RAM memory: nVidia Corporation C51 Host Bridge (rev a2)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0
	Capabilities: <access denied>

00:00.6 RAM memory: nVidia Corporation C51 Memory Controller 3 (rev a2)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B-
	Status: Cap- 66MHz+ UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-

00:00.7 RAM memory: nVidia Corporation C51 Memory Controller 2 (rev a2)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap- 66MHz+ UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-

00:02.0 PCI bridge: nVidia Corporation C51 PCI Express Bridge (rev a1) (prog-if 00 [Normal decode])
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0, Cache Line Size: 64 bytes
	Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
	Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR-
	BridgeCtl: Parity- SERR- NoISA+ VGA- MAbort- >Reset- FastB2B-
	Capabilities: <access denied>

00:03.0 PCI bridge: nVidia Corporation C51 PCI Express Bridge (rev a1) (prog-if 00 [Normal decode])
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0, Cache Line Size: 64 bytes
	Bus: primary=00, secondary=02, subordinate=02, sec-latency=0
	I/O behind bridge: 00004000-00004fff
	Memory behind bridge: c4000000-c40fffff
	Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR-
	BridgeCtl: Parity- SERR- NoISA+ VGA- MAbort- >Reset- FastB2B-
	Capabilities: <access denied>

00:04.0 PCI bridge: nVidia Corporation C51 PCI Express Bridge (rev a1) (prog-if 00 [Normal decode])
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0, Cache Line Size: 64 bytes
	Bus: primary=00, secondary=03, subordinate=03, sec-latency=0
	Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR-
	BridgeCtl: Parity- SERR- NoISA+ VGA- MAbort- >Reset- FastB2B-
	Capabilities: <access denied>

00:05.0 VGA compatible controller: nVidia Corporation MCP51 PCI-X GeForce Go 6100 (rev a2) (prog-if 00 [VGA controller])
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0
	Interrupt: pin A routed to IRQ 21
	Region 0: Memory at c2000000 (32-bit, non-prefetchable) [size=16M]
	Region 1: Memory at d0000000 (64-bit, prefetchable) [size=256M]
	Region 3: Memory at c1000000 (64-bit, non-prefetchable) [size=16M]
	[virtual] Expansion ROM at c3100000 [disabled] [size=128K]
	Capabilities: <access denied>

00:09.0 RAM memory: nVidia Corporation MCP51 Host Bridge (rev a2)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0
	Capabilities: <access denied>

00:0a.0 ISA bridge: nVidia Corporation MCP51 LPC Bridge (rev a3)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O+ Mem+ BusMaster+ SpecCycle+ MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap- 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0

00:0a.1 SMBus: nVidia Corporation MCP51 SMBus (rev a3)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Interrupt: pin A routed to IRQ 10
	Region 4: I/O ports at 3040 [size=64]
	Region 5: I/O ports at 3000 [size=64]
	Capabilities: <access denied>

00:0a.3 Co-processor: nVidia Corporation MCP51 PMU (rev a3)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap- 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0 (750ns min, 250ns max)
	Interrupt: pin B routed to IRQ 11
	Region 0: Memory at c0040000 (32-bit, non-prefetchable) [size=256K]

00:0b.0 USB Controller: nVidia Corporation MCP51 USB Controller (rev a3) (prog-if 10 [OHCI])
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0 (750ns min, 250ns max)
	Interrupt: pin A routed to IRQ 16
	Region 0: Memory at c0004000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: <access denied>

00:0b.1 USB Controller: nVidia Corporation MCP51 USB Controller (rev a3) (prog-if 20 [EHCI])
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0 (750ns min, 250ns max)
	Interrupt: pin B routed to IRQ 17
	Region 0: Memory at c0005000 (32-bit, non-prefetchable) [size=256]
	Capabilities: <access denied>

00:0d.0 IDE interface: nVidia Corporation MCP51 IDE (rev f1) (prog-if 8a [Master SecP PriP])
	Subsystem: Unknown device f025:0112
	Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0 (750ns min, 250ns max)
	Region 0: [virtual] Memory at 000001f0 (32-bit, non-prefetchable) [disabled] [size=8]
	Region 1: [virtual] Memory at 000003f0 (type 3, non-prefetchable) [disabled] [size=1]
	Region 2: [virtual] Memory at 00000170 (32-bit, non-prefetchable) [disabled] [size=8]
	Region 3: [virtual] Memory at 00000370 (type 3, non-prefetchable) [disabled] [size=1]
	Region 4: I/O ports at 3080 [size=16]
	Capabilities: <access denied>

00:0e.0 IDE interface: nVidia Corporation MCP51 Serial ATA Controller (rev f1) (prog-if 85 [Master SecO PriO])
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0 (750ns min, 250ns max)
	Interrupt: pin A routed to IRQ 19
	Region 0: I/O ports at 30b0 [size=8]
	Region 1: I/O ports at 30a4 [size=4]
	Region 2: I/O ports at 30a8 [size=8]
	Region 3: I/O ports at 30a0 [size=4]
	Region 4: I/O ports at 3090 [size=16]
	Region 5: Memory at c0006000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: <access denied>

00:10.0 PCI bridge: nVidia Corporation MCP51 PCI Bridge (rev a2) (prog-if 01 [Subtractive decode])
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0
	Bus: primary=00, secondary=04, subordinate=08, sec-latency=64
	Memory behind bridge: c3000000-c30fffff
	Secondary status: 66MHz- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- <SERR- <PERR-
	BridgeCtl: Parity- SERR- NoISA+ VGA- MAbort- >Reset- FastB2B-
	Capabilities: <access denied>

00:10.1 Audio device: nVidia Corporation MCP51 High Definition Audio (rev a2)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0 (500ns min, 1250ns max)
	Interrupt: pin B routed to IRQ 22
	Region 0: Memory at c0000000 (32-bit, non-prefetchable) [size=16K]
	Capabilities: <access denied>

00:14.0 Bridge: nVidia Corporation MCP51 Ethernet Controller (rev a3)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 0 (250ns min, 5000ns max)
	Interrupt: pin A routed to IRQ 18
	Region 0: Memory at c0007000 (32-bit, non-prefetchable) [size=4K]
	Region 1: I/O ports at 30b8 [size=8]
	Capabilities: <access denied>

00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration
	Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Capabilities: <access denied>

00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map
	Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-

00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller
	Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-

00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control
	Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Capabilities: <access denied>

04:05.0 Ethernet controller: Atheros Communications Inc. AR2413 802.11bg NIC (rev 01)
	Subsystem: AMBIT Microsystem Corp. Unknown device 0418
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV+ VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 168 (2500ns min, 7000ns max), Cache Line Size: 64 bytes
	Interrupt: pin A routed to IRQ 20
	Region 0: Memory at c3000000 (32-bit, non-prefetchable) [size=64K]
	Capabilities: <access denied>

04:06.0 CardBus bridge: Texas Instruments PCIxx12 Cardbus Controller
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 168, Cache Line Size: 128 bytes
	Interrupt: pin A routed to IRQ 11
	Region 0: Memory at c3010000 (32-bit, non-prefetchable) [size=4K]
	Bus: primary=04, secondary=05, subordinate=08, sec-latency=176
	Memory window 0: c8000000-cbfff000 (prefetchable)
	Memory window 1: cc000000-cffff000
	I/O window 0: 00001c00-00001cff
	I/O window 1: 00002400-000024ff
	BridgeCtl: Parity- SERR- ISA- VGA- MAbort- >Reset+ 16bInt+ PostWrite+
	16-bit legacy interface ports at 0001

04:06.2 Mass storage controller: Texas Instruments 5-in-1 Multimedia Card Reader (SD/MMC/MS/MS PRO/xD)
	Subsystem: Acer Incorporated [ALI] Unknown device 0112
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
	Latency: 64 (1750ns min, 1000ns max), Cache Line Size: 64 bytes
	Interrupt: pin A routed to IRQ 11
	Region 0: Memory at c3012000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: <access denied>