[SOLVED] Network interface is not shown in ifconfig command

mahmoodn · 04-13-2016, 05:29 AM

I have wrote a network config file to bring up the third network controller on a server running Centos-6.1

Code:

$ cat /etc/sysconfig/network-scripts/ifcfg-eth2
DEVICE=eth2
BOOTPROTO=none
NETMASK=255.255.240.0
TYPE=Ethernet
HWADDR=00:e0:81:c6:d7:01
IPADDR=172.16.48.70
GATEWAY=172.16.48.1
IPV6INIT=no
ONBOOT=no
USERCTL=no
$ ls /etc/sysconfig/network-scripts/ifcfg*
/etc/sysconfig/network-scripts/ifcfg-eth0  /etc/sysconfig/network-scripts/ifcfg-eth2
/etc/sysconfig/network-scripts/ifcfg-eth1  /etc/sysconfig/network-scripts/ifcfg-lo

However, the ifconfig command doesn't show eth2

Code:

$ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:E0:81:C6:D5:35
          inet addr:10.10.10.1  Bcast:10.10.10.255  Mask:255.255.255.0
          inet6 addr: fe80::2e0:81ff:fec6:d535/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:21107 errors:0 dropped:0 overruns:0 frame:0
          TX packets:11464 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:2243790 (2.1 MiB)  TX bytes:883788 (863.0 KiB)
          Memory:fe8c0000-fe8e0000

eth1      Link encap:Ethernet  HWaddr 00:E0:81:C6:D5:34
          inet addr:172.20.54.10  Bcast:172.20.54.255  Mask:255.255.255.0
          inet6 addr: fe80::2e0:81ff:fec6:d534/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:10879 errors:0 dropped:0 overruns:0 frame:0
          TX packets:30033 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:13811827 (13.1 MiB)  TX bytes:3538307 (3.3 MiB)
          Memory:fe7c0000-fe7e0000

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:16436  Metric:1
          RX packets:23309 errors:0 dropped:0 overruns:0 frame:0
          TX packets:23309 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:7275573 (6.9 MiB)  TX bytes:7275573 (6.9 MiB)

vmnet1    Link encap:Ethernet  HWaddr 00:50:56:C0:00:01
          inet addr:192.168.91.1  Bcast:192.168.91.255  Mask:255.255.255.0
          inet6 addr: fe80::250:56ff:fec0:1/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

vmnet8    Link encap:Ethernet  HWaddr 00:50:56:C0:00:08
          inet addr:172.16.2.1  Bcast:172.16.2.255  Mask:255.255.255.0
          inet6 addr: fe80::250:56ff:fec0:8/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

You may think that the third network controller is disabled through BIOS, but it is actually there

Code:

$ dmesg | grep -i intel
  Intel GenuineIntel
e1000e: Intel(R) PRO/1000 Network Driver - 1.9.5-k
e1000e: Copyright(c) 1999 - 2012 Intel Corporation.
e1000e 0000:03:00.0: eth0: Intel(R) PRO/1000 Network Connection
igb: Intel(R) Gigabit Ethernet Network Driver - version 3.2.10-k
igb: Copyright (c) 2007-2011 Intel Corporation.
igb 0000:02:00.0: Intel(R) Gigabit Ethernet Network Connection
igb 0000:02:00.1: Intel(R) Gigabit Ethernet Network Connection

I even rebooted the machine but still have this problem

ferrari · 04-13-2016, 05:55 AM

Use hwinfo or lshw to show us the network hardware, drivers, and network device nodes assigned.

Code:

lshw -class network

You may need to install one of those utilities first.

mahmoodn · 04-13-2016, 06:22 AM

Please see the output. Why the first one is disables?

Code:

# lshw -class network
  *-network DISABLED
       description: Ethernet interface
       product: 82574L Gigabit Network Connection
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: eth2
       version: 00
       serial: 00:e0:81:c6:d7:01
       size: 100Mbit/s
       capacity: 1Gbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=1.9.5-k duplex=full firmware=1.8-0 latency=0 link=no multicast=yes port=twisted pair speed=100Mbit/s
       resources: irq:48 memory:fe9e0000-fe9fffff ioport:c800(size=32) memory:fe9dc000-fe9dffff
  *-network:0
       description: Ethernet interface
       product: 82576 Gigabit Network Connection
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: eth1
       version: 01
       serial: 00:e0:81:c6:d5:34
       size: 100Mbit/s
       capacity: 1Gbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: pm msi msix pciexpress bus_master cap_list rom ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=igb driverversion=3.2.10-k duplex=full firmware=1.4-3 ip=172.20.54.10 latency=0 link=yes multicast=yes port=twisted pair speed=100Mbit/s
       resources: irq:40 memory:fe7c0000-fe7dffff memory:fe780000-fe79ffff ioport:b400(size=32) memory:fe740000-fe743fff memory:fe720000-fe73ffff(prefetchable) memory:fe700000-fe71ffff memory:fe744000-fe763fff
  *-network:1
       description: Ethernet interface
       product: 82576 Gigabit Network Connection
       vendor: Intel Corporation
       physical id: 0.1
       bus info: pci@0000:02:00.1
       logical name: eth0
       version: 01
       serial: 00:e0:81:c6:d5:35
       size: 1Gbit/s
       capacity: 1Gbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: pm msi msix pciexpress bus_master cap_list rom ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=igb driverversion=3.2.10-k duplex=full firmware=1.4-3 ip=10.10.10.1 latency=0 link=yes multicast=yes port=twisted pair speed=1Gbit/s
       resources: irq:41 memory:fe8c0000-fe8dffff memory:fe880000-fe89ffff ioport:b800(size=32) memory:fe840000-fe843fff memory:fe820000-fe83ffff(prefetchable) memory:fe7a0000-fe7bffff memory:fe7e0000-fe7fffff

mahmoodn · 04-13-2016, 09:32 AM

My bad...
I saw that in the ifcfg-eth2 file, there is

Code:

ONBOOT=no

So, I changed it to yes and restarted the network via

Code:

/etc/init.d/network restart

Still eth2 is not shown in the ifconfig. I guess that a reboot will fix it, but want to know is there any on-the-fly method which doesn't require any reboot?

lazydog · 04-13-2016, 11:35 AM

What does the following command give you:

Code:

ifconfig -a

You will also notice that your ports are running at different speeds.

eth0=1000
eth1=100

Can you post the config file for eth2?

ferrari · 04-13-2016, 12:55 PM

@lazydug: Refer to the opening post for that info.

@mahmoodn: Yes, it should take effect next boot.

https://wiki.centos.org/FAQ/CentOS7#...dd5315906fa493

On the fly you should be able to do

Code:

sudo ifup eth2

mahmoodn · 04-13-2016, 01:22 PM

OK thank you very much ferarri, that command actually activated eth2.

Many thanks.

lazydog · 04-13-2016, 01:35 PM

Quote:

Originally Posted by ferrari

@lazydug: Refer to the opening post for that info.

Actually no, the first post did not give what I asked for.
That command 'ifconfig' will only give you up interfaces only.
'ifconfig -a' will give you all interface both up and down.

But it is neither here nor there now that the OP has activated his interface.

ferrari · 04-13-2016, 05:55 PM

The lshw output confirmed the status and node name associated with the hardware.

ferrari · 04-13-2016, 05:55 PM

Quote:

OK thank you very much ferarri, that command actually activated eth2.

Many thanks.

Happy to have been of help.