Duplicate ipv6 global 2001 address issue . Redhat

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Posted on March 08, 2018

IPV6 test case

If we set a static ipv6 and IPV6_AUTOCONF was set to yes. the IPV6_AUTOCONF value will not take affect until we bring down the interface and bring it back up. Performing a network restar will not change the value of IPV6_AUTOCONF.. We have found that after a restart of the network service. The interface receives a second global 2001 address.

steps to duplicate

1. Add IPV6ADDR=
2. IPV6_AUTOCONF=yes change to no
3. restart the network manager or service

4. if you want to set the default gW use IPV6_DEFAULTGW= . This may be requires as router advertisements will be disabled. RA is required to received the GW information from the router.

Possible fix is to restart the interface or the below.
Set net.ipv6.conf.eth0.accept_ra to on in the sysctl file and set autoconf to off.

net.ipv6.conf.eth0.autoconf = 0

net.ipv6.conf.eth0.accept_ra = 1 << enable router advertisments /sbin/sysctl -a | grep net.ipv6.conf. << check settings