Recently, we tried to take a network interface down on a VM, when we executed the command
ifdown eth0
we got the following error:
ERROR : [/etc/sysconfig/network-scripts/ifdown-eth] Device has MAC address 00:00:00:00:00:00 00:45:4D:04:02:36 00:45:4D:04:02:40, instead of configured address 00:45:4D:16:0B:29. Ignoring.
We used ifconfig eth0 to check the information on the network interfaces which resulted in the following data:
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 10.1.20.115 netmask 255.255.255.0 broadcast 10.1.20.255 inet6 fe80::215:5dff:fe01:236 prefixlen 64 scopeid 0x20<link> ether 00:45:4d:04:02:36 txqueuelen 1000 (Ethernet) RX packets 10103919 bytes 5474528935 (5.0 GiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 6541413 bytes 1190276207 (1.1 GiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
We saw that the value ether for eth0 was 00:45:4d:04:02:36, which was one of the addresses the warning mentioned that are valid.
Apparently, we had an error in the following configuration file:
/etc/sysconfig/network-scripts/ifcfg-eth0
The value for HWADDR was set to 00:45:4D:16:0B:29 which was wrong (most likely this file was copied here from another source), after we updated the value to 00:45:4d:04:02:36 we were able to use the device normally.
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