重新启动计算机后，IPv6 地址会丢失。
[root@VM-1-47-centos ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 52:54:00:91:23:c3 brd ff:ff:ff:ff:ff:ff
inet 172.16.1.47/24 brd 172.16.1.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::5054:ff:fe91:23c3/64 scope link
valid_lft forever preferred_lft forever
没有 IPv6 地址
/etc/redhat-release: centos 7.3
重启时DHCP分配了IPv6地址，10秒后，IPv6地址丢失，搜索journalctl日志发现：
ntpd[547]: Deleting interface #4 eth0, 2402:4e00:1717:ee01:0:987a:c739:1bb6#123, interface stats: received=0, sent=0, dropped=0, active_time=10 secs
journalctl日志是：
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: Cloud-init v. 20.1 running 'init' at Wed, 22 Feb 2023 10:01:02 +0000. Up 161.49 seconds.
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: +++++++++++++++++++++++++++++++++++++++++++++Net device info+++++++++++++++++++++++++++++++++++++++++++++
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: +--------+------+------------------------------------------+---------------+--------+-------------------+
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | Device | Up | Address | Mask | Scope | Hw-Address |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: +--------+------+------------------------------------------+---------------+--------+-------------------+
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | eth0 | True | 172.16.1.47 | 255.255.255.0 | global | 52:54:00:91:23:c3 |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | eth0 | True | 2402:4e00:1717:ee01:0:987a:c739:1bb6/128 | . | global | 52:54:00:91:23:c3 |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | eth0 | True | fe80::5054:ff:fe91:23c3/64 | . | link | 52:54:00:91:23:c3 |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | lo | True | 127.0.0.1 | 255.0.0.0 | host | . |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | lo | True | ::1/128 | . | host | . |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: +--------+------+------------------------------------------+---------------+--------+-------------------+
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: ++++++++++++++++++++++++++++Route IPv4 info+++++++++++++++++++++++++++++
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: +-------+-------------+------------+---------------+-----------+-------+
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | Route | Destination | Gateway | Genmask | Interface | Flags |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: +-------+-------------+------------+---------------+-----------+-------+
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | 0 | 0.0.0.0 | 172.16.1.1 | 0.0.0.0 | eth0 | UG |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | 1 | 169.254.0.0 | 0.0.0.0 | 255.255.0.0 | eth0 | U |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | 2 | 172.16.1.0 | 0.0.0.0 | 255.255.255.0 | eth0 | U |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: +-------+-------------+------------+---------------+-----------+-------+
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: ++++++++++++++++++++++++++++++++++++++++Route IPv6 info+++++++++++++++++++++++++++++++++++++++++
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Started Initial cloud-init job (metadata service crawler).
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: +-------+--------------------------------------+---------------------------+-----------+-------+
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | Route | Destination | Gateway | Interface | Flags |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: +-------+--------------------------------------+---------------------------+-----------+-------+
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | 8 | 2402:4e00:1717:ee01:0:987a:c739:1bb6 | :: | eth0 | Ue |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | 9 | 2402:4e00:1717:ee01::/64 | :: | eth0 | U |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | 11 | fe80::/64 | :: | eth0 | U |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | 12 | ::/0 | fe80::feee:ffff:feff:ffff | eth0 | UG |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: | 17 | ff00::/8 | :: | eth0 | U |
Feb 22 18:01:02 VM-1-47-centos cloud-init[967]: ci-info: +-------+--------------------------------------+---------------------------+-----------+-------+
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Starting OpenSSH server daemon...
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Starting Permit User Sessions...
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Starting /etc/rc.d/rc.local Compatibility...
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Reached target Network is Online.
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Starting System Logging Service...
Feb 22 18:01:02 VM-1-47-centos kdumpctl[983]: No memory reserved for crash kernel
Feb 22 18:01:02 VM-1-47-centos kdumpctl[983]: Starting kdump: [FAILED]
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Starting Crash recovery kernel arming...
Feb 22 18:01:02 VM-1-47-centos crond[1021]: (CRON) INFO (RANDOM_DELAY will be scaled with factor 98% if used.)
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Reached target Cloud-config availability.
Feb 22 18:01:02 VM-1-47-centos ntpd[546]: Listen normally on 4 eth0 2402:4e00:1717:ee01:0:987a:c739:1bb6 UDP 123
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Starting Apply the settings specified in cloud-config...
Feb 22 18:01:02 VM-1-47-centos ntpd[546]: new interface(s) found: waking up resolver
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Started Permit User Sessions.
Feb 22 18:01:03 VM-1-47-centos crond[1021]: (CRON) INFO (running with inotify support)
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Started Job spooling tools.
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Started Command Scheduler.
Feb 22 18:01:02 VM-1-47-centos systemd[1]: kdump.service: main process exited, code=exited, status=1/FAILURE
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Failed to start Crash recovery kernel arming.
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Unit kdump.service entered failed state.
Feb 22 18:01:02 VM-1-47-centos systemd[1]: kdump.service failed.
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Started /etc/rc.d/rc.local Compatibility.
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Starting Wait for Plymouth Boot Screen to Quit...
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Starting Terminate Plymouth Boot Screen...
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Received SIGRTMIN+21 from PID 218 (plymouthd).
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Started Terminate Plymouth Boot Screen.
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Started Wait for Plymouth Boot Screen to Quit.
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Started Getty on tty1.
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Started Serial Getty on ttyS0.
Feb 22 18:01:02 VM-1-47-centos systemd[1]: Reached target Login Prompts.
Feb 22 18:01:03 VM-1-47-centos sshd[979]: Server listening on 0.0.0.0 port 22.
Feb 22 18:01:03 VM-1-47-centos systemd[1]: Started OpenSSH server daemon.
Feb 22 18:01:03 VM-1-47-centos sshd[979]: Server listening on :: port 22.
Feb 22 18:01:03 VM-1-47-centos cloud-init[984]: Cloud-init v. 20.1 running 'modules:config' at Wed, 22 Feb 2023 10:01:02 +0000. Up 162.20 seconds.
Feb 22 18:01:03 VM-1-47-centos systemd[1]: Started Apply the settings specified in cloud-config.
Feb 22 18:01:03 VM-1-47-centos systemd[1]: Starting Execute cloud user/final scripts...
Feb 22 18:01:03 VM-1-47-centos rsyslogd[982]: [origin software="rsyslogd" swVersion="8.24.0-52.el7_8.2" x-pid="982" x-info="http://www.rsyslog.com"] start
Feb 22 18:01:03 VM-1-47-centos systemd[1]: Started System Logging Service.
Feb 22 18:01:04 VM-1-47-centos cloud-init[1062]: Cloud-init v. 20.1 running 'modules:final' at Wed, 22 Feb 2023 10:01:03 +0000. Up 163.16 seconds.
Feb 22 18:01:04 VM-1-47-centos cloud-init[1062]: Cloud-init v. 20.1 finished at Wed, 22 Feb 2023 10:01:04 +0000. Datasource DataSourceConfigDrive [local,ver=2][source=/dev/sr0]. Up 163.56 seconds
Feb 22 18:01:04 VM-1-47-centos kernel: ISO 9660 Extensions: Microsoft Joliet Level 3
Feb 22 18:01:04 VM-1-47-centos kernel: ISO 9660 Extensions: RRIP_1991A
Feb 22 18:01:04 VM-1-47-centos systemd[1]: Started Execute cloud user/final scripts.
Feb 22 18:01:10 VM-1-47-centos systemd[1]: Started Dynamic System Tuning Daemon.
Feb 22 18:01:10 VM-1-47-centos systemd[1]: Reached target Multi-User System.
Feb 22 18:01:10 VM-1-47-centos systemd[1]: Reached target Cloud-init target.
Feb 22 18:01:10 VM-1-47-centos systemd[1]: Starting Update UTMP about System Runlevel Changes...
Feb 22 18:01:10 VM-1-47-centos systemd[1]: Started Update UTMP about System Runlevel Changes.
Feb 22 18:01:10 VM-1-47-centos systemd[1]: Startup finished in 807ms (kernel) + 16.710s (initrd) + 2min 32.575s (userspace) = 2min 50.093s.
Feb 22 18:01:11 VM-1-47-centos ntpd[546]: Deleting interface #4 eth0, 2402:4e00:1717:ee01:0:987a:c739:1bb6#123, interface stats: received=0, sent=0, dropped=0, active_time=9 secs
Feb 22 18:01:11 VM-1-47-centos ntpd[546]: Deleting interface #3 eth0, fe80::5054:ff:fe91:23c3#123, interface stats: received=0, sent=0, dropped=0, active_time=28 secs
Feb 22 18:01:13 VM-1-47-centos ntpd[546]: Listen normally on 5 eth0 fe80::5054:ff:fe91:23c3 UDP 123
Feb 22 18:01:13 VM-1-47-centos ntpd[546]: new interface(s) found: waking up resolver
Feb 22 18:01:17 VM-1-47-centos systemd[1]: Created slice User Slice of root.
Feb 22 18:01:17 VM-1-47-centos systemd[1]: Started Session 1 of user root.
Feb 22 18:01:17 VM-1-47-centos systemd-logind[532]: New session 1 of user root.
Feb 22 18:01:17 VM-1-47-centos login[1045]: pam_unix(login:session): session opened for user root by LOGIN(uid=0)
Feb 22 18:01:17 VM-1-47-centos login[1045]: DIALUP AT ttyS0 BY root
Feb 22 18:01:17 VM-1-47-centos login[1045]: ROOT LOGIN ON ttyS0
Feb 22 18:01:21 VM-1-47-centos dbus[533]: [system] Activating service name='org.freedesktop.problems' (using servicehelper)
Feb 22 18:01:22 VM-1-47-centos dbus[533]: [system] Successfully activated service 'org.freedesktop.problems'
我尝试在以下人员的帮助下解决这个问题这篇 RedHat 知识库文章但它不起作用。