Wicked keeps DUID on SLES15 even when NIC is replaced

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Environment

SUSE Linux Enterprise Server 15

Situation

On systems running SLE15, wicked will not create new DHCP Unique Identifier (DUID) automatically when NIC was replaced or the (virtualized) system was created by cloning. DUID is mandatory when using DHCPv6.

This also can be seen when changing assigned IP Address or Hostname from DHCP Server side. The SLES15 client will not take these changes.

SLE15 behaves like upstream now, see below for further information.

Resolution

To fix this issue, all files under ( /var/lib/wicked/*.xml ) should be removed. When server startup or when restarting wicked service; wicked will automatically recreate these files and server will have new DUID based on the MAC address.

Removing such files can be done before cloning/changing the network interface.

Cause

According to: https://tools.ietf.org/html/rfc3315

"...The DUID is designed to be unique across all DHCP clients and servers, and stable for any specific client or server - that is, the DUID used by a client or server SHOULD NOT change over time if at all possible; for example, a device's DUID should not change as a result of a change in the device's network hardware."

Additional Information

Also, /etc/machine-id should be removed when cloning servers. This file will be auto generated if it doesn't exists.

Note: On SLES 12, wicked still will automatically generate DUID upon MAC address change.

Disclaimer

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