Situation

Wir hatten bei einer VMware vCenter Server Appliance mit der Version 7 das Problem, das nach einem neustart die IPv6 Konfiguration nicht mehr im Backend zu sehen war. Zudem war das System nicht mehr via IPv6 erreichbar.

Workaround

 Main Menu

0)      Show Current Configuration (scroll with Shift-PgUp/PgDown)
1)      Exit this program
2)      Default Gateway
3)      Hostname
4)      DNS
5)      Proxy Server
6)      IP Address Allocation for eth0
Enter a menu number [0]: 6
Type Ctrl-C to go back to the Main Menu

Configure an IPv6 address for eth0? y/n [n]: y
Use a DHCPv6 Server instead of a static IPv6 address? y/n [n]:
IPv6 Address []: 2a0c:3b80::1234
Prefix []: 64
Is this correct? y/n [y]: y

Configure an IPv4 address for eth0? y/n [n]: y
Use a DHCPv4 Server instead of a static IPv4 address? y/n [n]:
IPv4 Address [194.50.99.55]:
Netmask [255.255.255.0]:
Is this correct? y/n [y]: y

Reconfiguring eth0...
net.ipv6.conf.eth0.disable_ipv6 = 0

Network parameters successfully changed to requested values

 Main Menu

0)      Show Current Configuration (scroll with Shift-PgUp/PgDown)
1)      Exit this program
2)      Default Gateway
3)      Hostname
4)      DNS
5)      Proxy Server
6)      IP Address Allocation for eth0
Enter a menu number [0]: 2

Warning: if any of the interfaces for this VM use DHCP,
the Hostname, DNS, and Gateway parameters will be
overwritten by information from the DHCP server.

Type Ctrl-C to go back to the Main Menu

0)      eth0
Choose the interface to associate with default gateway [0]: 0
Gateway will be associated with eth0
IPv4 Default Gateway [194.50.99.254]:
IPv6 Default Gateway []: 2a0c:3b80::1234
Reconfiguring eth0...
net.ipv6.conf.eth0.disable_ipv6 = 0
Network parameters successfully changed to requested values