Table of Contents

CentOS IPV6 settings

The configuration below works perfectly : 

# ifconfig eth0 x.x.x.x/29
# route add defalt gw x.x.x.x
 
# ip addr add dev eth0 XXXX:C810:3001:D00::3/56
# ip -6 route add default XXXX:C810:3001:D00::1

However, I want to keep this configuration after a reboot.

So I made the following configuration:

Enabling IPv6

[root@test network-scripts]# cat /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=test.net
NETWORKING_IPV6=yes

Interface Configuration

[root@test network-scripts]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 
DEVICE="eth0"
BOOTPROTO="static"
ONBOOT="yes"
HWADDR="2C:C3:AC:A8:C3:3E"
IPADDR=x.x.x.x
GATEWAY=x.x.x.x
NETMASK=255.255.255.248
TYPE=Ethernet
IPV6INIT=yes
IPV6ADDR=XXXX:C810:3001:D00::3/56
IPV6_DEFAULTGW=XXXX:C810:3001:D00::1
 
DNS1=208.67.222.222
DNS2=208.67.220.220
# Only DNS{1,2} according to /usr/share/doc/initscripts-9.03.27/sysconfig.txt
# DNS3=2620:0:ccc::2
# DNS4=2620:0:ccD::2

Restarting the Network

[root@test network-scripts]# service network restart
Arrêt de l'interface eth0 :  État du périphérique : 3 (déconnecté)
                                                           [  OK  ]
Arrêt de l'interface loopback :                            [  OK  ]
Activation de l'interface loopback :                       [  OK  ]
Activation de l'interface eth0 :  État de connexion active : activation
État de chemin actif : /org/freedesktop/NetworkManager/ActiveConnection/3
état : activé
Connexion activée
                                                           [  OK  ]

[root@test network-scripts]# ip addr show

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    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 qlen 1000
    link/ether 1c:c1:de:b8:a3:fd brd ff:ff:ff:ff:ff:ff
    inet x.x.x.x/29 brd x.x.x.x scope global eth0
    inet6 fe80::1ec1:deff:feb8:a3fd/64 scope link 
       valid_lft forever preferred_lft forever

IPv6 addresses of the resolvers are not even in the resolv.conf !