NetworkManager errors / warnings

Apr 25 00:22:01 hosting NetworkManager[676]:   [1745558521.6932] platform-linux: do-add-ip6-address[2: fe80::250:56ff:fe40:f5e8]: failure 13 (Permission denied)
Apr 25 00:22:03 hosting NetworkManager[676]:   [1745558523.6955] ipv6ll[7815b866a956efe0,ifindex=2]: changed: no IPv6 link local address to retry after Duplicate Address Detection failures (back off)
Apr 25 00:22:03 hosting NetworkManager[676]:   [1745558523.6958] platform: (eth0) route-sync: failure to add IPv6 route: type unicast fe80::1/128 dev 2 metric 100 mss 0 rt-src user: Permission denied
Apr 25 00:22:13 hosting NetworkManager[676]:   [1745558533.7064] platform-linux: do-add-ip6-address[2: fe80::250:56ff:fe40:f5e8]: failure 13 (Permission denied)
Apr 25 00:22:15 hosting NetworkManager[676]:   [1745558535.7089] ipv6ll[7815b866a956efe0,ifindex=2]: changed: no IPv6 link local address to retry after Duplicate Address Detection failures (back off)
Apr 25 00:22:15 hosting NetworkManager[676]:   [1745558535.7093] platform: (eth0) route-sync: failure to add IPv6 route: type unicast fe80::1/128 dev 2 metric 100 mss 0 rt-src user: Permission denied

Apache log file shows these lines. Should I ignore or should I fix this?

If unused, consider disabling IPv6 to simplify your network stack (I have):
https://webhostinggeeks.com/howto/disable-ipv6-on-redhat-centos-6-centos-7/

IPV6 is already disabled in kernel

Should it be disabled in networkmanager?

If it's disabled in the kernel, there shouldn't be anything left to do (after rebooting). Can you show the results of

Code: [Select]

ip a  | grep net6

If you don't want IPv6 and are using AlmaLinux, you can use nmtui and disable it.

If it's disabled in the kernel, there shouldn't be anything left to do (after rebooting). Can you show the results of

Code: [Select]

ip a  | grep net6

[root@hosting ~]# ip a  | grep net6
[root@hosting ~]# ip a  | grep net6

If you don't want IPv6 and are using AlmaLinux, you can use nmtui and disable it.

#nmcli connection show

NAME         UUID                                  TYPE      DEVICE
System eth0  3521111a-4fxx-43xx-x444-1xxxxxxxxx0  ethernet  eth0

# nmcli connection modify System ipv6.method "disabled"
Error: unknown connection 'System'.

What is the connection name I should use?

If you don't want IPv6 and are using AlmaLinux, you can use nmtui and disable it.

#nmcli conn show "System eth0"
connection.id:                          System eth0

# nmcli connection modify "System eth0" ipv6.method "disabled"
Error: Failed to modify connection 'System eth0': ipv6.addresses: this property                                                                              is not allowed for 'method=disabled'

It wouldn't appear that IPv6 is enabled on your system, but you can double check here:

Code: [Select]

sysctl -a | grep -i ipv6
nmtui is a semi-graphical utility, so the procedure is not just a single command but a series of steps.
Invoke nmtui with sudo in a root shell: nmtui
Click on Edit a connection.
Select the interface you want to edit (eth0).
Go to IPv6 with the arrow keys on the keyboard.
Then select Disabled and click OK.
Run the ip a command from the terminal to confirm that IPv6 is no longer available.