Problem
On a CentOS Linux (7/8) box with IPv6 and EUI-64 generation mode configured, NetworkManager says that the address generation mode is stable-privacy.
Details and research
On our CentOS Linux boxes we use nmcli to rename network adapters. After that we move ifcfg-* files to the new names. This all works as excepted. Before the renaming of the adapter NetworkManagers says the IPv6 address generation mode is EUI-64:
nmcli connection show ens3 | grep addr-gen
ipv6.addr-gen-mode: eui64
But after renaming the adapter (and a reboot) the very same command show different output:
nmcli connection show eth-wan | grep addr-gen
ipv6.addr-gen-mode: stable-privacy
What I've tried
After researching various documentation I've tried different situations to 'restore' the EUI-64 configuration:
- Adding IPV6_PRIVACY=no and IPV6_ADDR_GEN_MODE=eui64 to ifcfg-*
- Executing
nmcli con mod eth-wan ipv6.addr-gen-mode eui64
None of the above result in a visible switch back to EUI-64. But after adding the options on the first situation, the IPv6 configuration effectively is using EUI-64. Even when NetworkManagers states otherwise. I tested this behaviour by watching ip addr output between all changes.
Concluding Questions
- Will it do any harm that NetworkManager gives other information than provided by the configuration?
- Is there any way to effectively change the visible NetworkManager configuration, so it is 'in sync' with the working running config?
