For the general case let's say that the virtual adapter for eth0 has been removed and replaced with another one. Either due to cloning or, more recently, a rash of MAC address conflicts. [Yes, a rash of them.]
Usually I simply rm /etc/udev/rules.d/70-persistent-net-rules and check that nothing in /etc/sysconfig/network* contains a reference to a MAC address and reboot, but this is Linux and there must be a way to avoid rebooting.
Is there a command I can run to pick up the new NIC?
edit
In addition to @dawud's answer below I ran into an issue on my test VM where it had already booted with the new device in place and had it named eth1 in which case udevadm does not seem to 'release' the device. In this case I did the following:
- Get the MAC address of the device from VSphere.
- Create/edit
/etc/iftabwith the lineeth0 mac ##:##:##:##:##:##substituting in the MAC address.ifrenamedoes not seem to like it when this file does not exist/contain the name of the destination interface. ifrename -i eth1 -n eth0service network restartand eth0 started up normally.- [Optional]
rm /etc/iftabso there's one less place for a MAC to live.
You can do that using
udevadm triggerYou still need to remove the persistent rules and restart the network service.
For me, the below command sequence has worked as expected.
I have done modifications in
/etc/udev/rules.d/70-persistent-net.rulesto change theethnumber and to reload them without rebooting./etc/init.d/networking stop/etc/init.d/udev stopudevadm control --reload-rules/etc/init.d/udev start/etc/init.d/networking startFollowing this, it successfully loaded without rebooting the machine.
Any suggestion or recommendations on this are welcome, I have discovered the above on my own by reading the MAN pages.