etho not seen in the ifconfig

Issues related to configuring your network
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pdk
Posts: 22
Joined: 2015/01/20 13:00:36

etho not seen in the ifconfig

Post by pdk » 2017/08/16 09:34:07

Hi All,

I created a new VM by using the image from others.

But now not sure why my etho is not showing up

On ifconfig i get:
eth4 Link encap:Ethernet HWaddr 08:00:27:F6:07:6D
inet6 addr: fe80::a00:27ff:fef6:76d/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:20 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:5256 (5.1 KiB)

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:16 errors:0 dropped:0 overruns:0 frame:0
TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0


And on
my VM setting, Network tab,

Adapter 1,
Attached to Bridage Adapter,
NAme : virbr0
Adapter Type: Intel PRO/1000 MT Desktop(8250EM)
MAC Address:0800276076D
CableConnected
Port Forwarding


And file /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE="eth0"
BOOTPRO=dhcp
NM_CONTROLLED="yes"
ONBOOT=yes
TYPE=Ethernet
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME="System eth0"
UUID=5fb06bd0-0bb0-7ffb-45f1-d6edd65f3e03
IPADDR=192.168.21.57
PREFIX=16
LAST_CONNECT=1421849

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TrevorH
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Re: etho not seen in the ifconfig

Post by TrevorH » 2017/08/16 09:40:57

I created a new VM by using the image from others.
Most likely because you cloned it from another image and changed the MAC address. It creates a new interface for each different MAC and adds 1 to the ethX number.
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pdk
Posts: 22
Joined: 2015/01/20 13:00:36

Re: etho not seen in the ifconfig

Post by pdk » 2017/08/16 09:46:36

Thanks a lot Trevor for hint, but then so what should I do ? ( Everything was setup for me initially , now I am back after long break, struggling to set up my setup)

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TrevorH
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Re: etho not seen in the ifconfig

Post by TrevorH » 2017/08/16 10:33:34

Either use the new name or track down all references to the old ones and remove them so it doesn't know it had a previous ethernet card installed. I believe the libguestfs package has tools to do this sort of thing for VM templates.
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CentOS 6 goes EOL sooner rather than later, get upgrading!
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pdk
Posts: 22
Joined: 2015/01/20 13:00:36

Re: etho not seen in the ifconfig

Post by pdk » 2017/08/16 10:47:00

Sorry but this is going over head for me, Im not systems engineer, but just use the setup. But being small company, has to setup my setup..Taking long time for me to come back to basic setup..

@Trevor, could you please help hinting the parameter in the file contents i cut paste above

tunk
Posts: 611
Joined: 2017/02/22 15:08:17

Re: etho not seen in the ifconfig

Post by tunk » 2017/08/16 10:51:55

BOOTPRO=dhcp
IPADDR=192.168.21.57
These two may conflict.

pdk
Posts: 22
Joined: 2015/01/20 13:00:36

Re: etho not seen in the ifconfig

Post by pdk » 2017/08/16 10:58:45

yes, the above hint is to change IP address of eth0.
But I still dont understand why ifconfig is showing the eth4.



ifconfig
eth4 Link encap:Ethernet HWaddr 08:00:27:F6:07:6D
inet6 addr: fe80::a00:27ff:fef6:76d/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:20 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:5256 (5.1 KiB)

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:16 errors:0 dropped:0 overruns:0 frame:0
TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0

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jlehtone
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Joined: 2007/12/11 08:17:33
Location: Finland

Re: etho not seen in the ifconfig

Post by jlehtone » 2017/08/16 11:41:48

The output of (some of) these should be rather interesting/illuminating:

Code: Select all

# cat /etc/udev/rules.d/70-persistent-net.rules
# ls -1 /etc/sysconfig/network-scripts/ifcfg-*
# ip ad
# ip ro
# chkconfig --list | grep -i netw

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TrevorH
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Re: etho not seen in the ifconfig

Post by TrevorH » 2017/08/16 15:01:12

It shows eth4 because this is the 4th ethernet card with differing MAC addresses that it has "seen" so far. A MAC address is a 12 digit hexadecimal string that is unique and is not the same thing as an ip address. NetworkManager is detecting a "new" ethernet card and creating a new interface name for it since it thinks it is a different card as its MAC address is different.
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CentOS 6 goes EOL sooner rather than later, get upgrading!
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