# eth1 not detecting link, despite NIC link light

## humbletech99

I have a linux firewall which has a network card, eth1 that insists the link is down, despite having a link light on the card itself. I have used ethtool to check and the result is as follows:

```
# ./ethtool eth1

Settings for eth1:

        Supported ports: [ TP MII ]

        Supported link modes:   10baseT/Half 10baseT/Full 

                                100baseT/Half 100baseT/Full 

        Supports auto-negotiation: Yes

        Advertised link modes:  10baseT/Half 10baseT/Full 

                                100baseT/Half 100baseT/Full 

        Advertised auto-negotiation: Yes

        Speed: 10Mb/s

        Duplex: Half

        Port: MII

        PHYAD: 1

        Transceiver: internal

        Auto-negotiation: on

        Current message level: 0x000020c1 (8385)

        Link detected: no
```

There is a statically assigned ip address and the cable is definitely plugged into the NIC and the other end into the switch. There is even data activity light blinking, but linux still doesn't see the link.

```
# ifconfig eth1

eth1      Link encap:Ethernet  HWaddr xx:xx:xx:xx:xx:xx

          inet addr:x.x.x.x  Bcast:x.x.x.x  Mask:x.x.x.x

          UP BROADCAST MULTICAST  MTU:1500  Metric:1

          RX packets:0 errors:0 dropped:0 overruns:0 frame:0

          TX packets:867 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000 

          RX bytes:0 (0.0 b)  TX bytes:36414 (35.5 Kb)

          Interrupt:4 
```

So the link does not appear up, despite what the hardware says. The kernel definitely detects the card, otherwise there would be no eth1. I can ping the eth1 ip address from the box itself but not from anywhere else on the network, and nor can the box ping anything anywhere else.

It looks like it is not receiving any packets at all. I have changed switch ports, the cable, and used a second switch. Both switches have other devices working on them.

I have changed network cards, pci slots, rebooted several times etc.

This was working fine with the original network card and the ip address up until yesterday when there was a power failure and the machine went down hard. I am leaning towards broken hardware, but I've changed the NIC, the switch, the cable and used different pci slots. There is another network card in the box which still works... but I need two interfaces since it's a firewall.

I am truly stuck. Any ideas?

----------

## gigantor31

I am experiencing the same issue after a power failure a few weeks ago.  Fortunately I am able to move computer, wireless AP, and test server to my main wan router; however, what blows is the file server that runs on this router is unavailable.

here's what I'm seeing:

ethtool =

```

Settings for eth1:

        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 pause frame use: No

        Advertised auto-negotiation: Yes

        Speed: 1000Mb/s

        Duplex: Full

        Port: Twisted Pair

        PHYAD: 1

        Transceiver: internal

        Auto-negotiation: on

        MDI-X: on

        Supports Wake-on: pumbag

        Wake-on: g

        Current message level: 0x00000001 (1)

                               drv

        Link detected: yes

```

ifconfig =

```

eth0      Link encap:Ethernet  HWaddr 00:1b:21:61:44:62

          inet addr:192.168.1.4  Bcast:192.168.1.255  Mask:255.255.255.0

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:9490 errors:0 dropped:0 overruns:0 frame:0

          TX packets:5337 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:10000

          RX bytes:1583166 (1.5 MiB)  TX bytes:1015302 (991.5 KiB)

          Memory:fe9e0000-fea00000

eth1      Link encap:Ethernet  HWaddr 00:1b:21:61:44:0e

          inet addr:10.10.20.250  Bcast:10.10.20.255  Mask:255.255.255.0

          UP BROADCAST RUNNING MULTICAST  MTU:9014  Metric:1

          RX packets:0 errors:0 dropped:0 overruns:0 frame:0

          TX packets:211 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:50000

          RX bytes:0 (0.0 B)  TX bytes:22095 (21.5 KiB)

          Memory:febe0000-fec00000

lo        Link encap:Local Loopback

          inet addr:127.0.0.1  Mask:255.0.0.0

          UP LOOPBACK RUNNING  MTU:16436  Metric:1

          RX packets:270 errors:0 dropped:0 overruns:0 frame:0

          TX packets:270 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:0

          RX bytes:14286 (13.9 KiB)  TX bytes:14286 (13.9 KiB)

```

The three NICs listed in lspci (only using both intel NICs)

```

01:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection

        Subsystem: Intel Corporation Gigabit CT Desktop Adapter

        Flags: bus master, fast devsel, latency 0, IRQ 16

        Memory at fe9e0000 (32-bit, non-prefetchable) [size=128K]

        Memory at fe900000 (32-bit, non-prefetchable) [size=512K]

        I/O ports at cc00 [size=32]

        Memory at fe9dc000 (32-bit, non-prefetchable) [size=16K]

        Expansion ROM at fe980000 [disabled] [size=256K]

        Capabilities: [c8] Power Management version 2

        Capabilities: [d0] MSI: Enable- Count=1/1 Maskable- 64bit+

        Capabilities: [e0] Express Endpoint, MSI 00

        Capabilities: [a0] MSI-X: Enable+ Count=5 Masked-

        Capabilities: [100] Advanced Error Reporting

        Capabilities: [140] Device Serial Number 00-1b-21-ff-ff-61-44-62

        Kernel driver in use: e1000e

02:00.0 Ethernet controller: Attansic Technology Corp. Atheros AR8121/AR8113/AR8114 PCI-E Ethernet Controller (rev b0)

        Subsystem: ASUSTeK Computer Inc. Device 831c

        Flags: bus master, fast devsel, latency 0, IRQ 17

        Memory at feac0000 (64-bit, non-prefetchable) [size=256K]

        I/O ports at dc00 [size=128]

        Capabilities: [40] Power Management version 2

        Capabilities: [48] MSI: Enable- Count=1/1 Maskable- 64bit+

        Capabilities: [58] Express Endpoint, MSI 00

        Capabilities: [100] Advanced Error Reporting

        Capabilities: [180] Device Serial Number ff-92-dc-68-20-cf-30-ff

        Kernel driver in use: ATL1E

03:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection

        Subsystem: Intel Corporation Gigabit CT Desktop Adapter

        Flags: bus master, fast devsel, latency 0, IRQ 16

        Memory at febe0000 (32-bit, non-prefetchable) [size=128K]

        Memory at feb00000 (32-bit, non-prefetchable) [size=512K]

        I/O ports at ec00 [size=32]

        Memory at febdc000 (32-bit, non-prefetchable) [size=16K]

        Expansion ROM at feb80000 [disabled] [size=256K]

        Capabilities: [c8] Power Management version 2

        Capabilities: [d0] MSI: Enable- Count=1/1 Maskable- 64bit+

        Capabilities: [e0] Express Endpoint, MSI 00

        Capabilities: [a0] MSI-X: Enable+ Count=5 Masked-

        Capabilities: [100] Advanced Error Reporting

        Capabilities: [140] Device Serial Number 00-1b-21-ff-ff-61-44-0e

        Kernel driver in use: e1000e

```

I'm thinking the eth1 NIC hardware is hosed and so I have another Intel EXPI9301CT being shipped.  Like humbletech99, any ideas.  And if the consensus is that this is a hardware issue, can I just replace with the same NIC once it arrives or do I have to reconfigure?  If so how?  Thanks much in advance.

----------

