Managing Serviceguard Nineteenth Edition, Reprinted June 2011

ndd -get /dev/ip6 ip6_nd_dad_solicit_count
If the result is 1, the feature is turned on. If the result is 0, the feature is turned off. To temporarily
change the state of DAD on your computer, use the ndd -set command to change the kernel
parameter.
ndd -set /dev/ip6 ip6_nd_dad_solicit_countn
where n is a number: either 1 to turn the feature on, or 0 to turn it off.
To change the state of DAD on your computer so that it will remain changed even after a reboot,
add the following entries to the /etc/rc/config.d/nddconffile:
TRANSPORT_NAME[index]=ip6
NDD_NAME[index]=ip6_nd_dad_solicit_count
NDD_VALUE[index]=n
Where index is the next available integer value of the nddconf file, and n is a number: either
1 to turn the feature ON or 0 to turn it OFF.
Local Primary/Standby LAN Patterns
The use of IPv6 allows a number of different patterns of failover among LAN cards configured in
the cluster. This is true because each LAN card can support several IP addresses when a dual
IPv4/IPv6 configuration is used. This section describes several ways in that local failover to a
standby LAN can be configured.
By definition, a standby network interface is an interface that has no IP address(es) of either address
family (IPv4 or IPv6) and is bridged to the primary network interface on a node.
Here are two guidelines to keep in mind when using IPv4 and IPv6 addresses in local failover
situations:
• Since a network interface card can have both an IPv4 and an IPv6 address as the primary
IPs, the standby network interface card could potentially act as a standby for both types of
primary interfaces.
However, if the IPv4 and IPv6 address(es) are configured on two separate network interfaces,
then the standby interface can take over the IP address from only one network interface during
a local failover.
That is, IPv4 and IPv6 addresses from two separate network interfaces are mutually exclusive
in a failover condition.
• Serviceguard will switch over link-local address configured on the primary network interface
along with all other IP addresses which are configured as part of the cluster configuration to
the standby network interface. This includes all heartbeat and stationary IPs (IPv4 and IPv6)
and package IPs (both IPv4 and IPv6) added by Serviceguard.
The examples that follow illustrate this.
Example Configurations
An example of a LAN configuration on a cluster node using both IPv4 and IPv6 addresses is shown
in below.
368 IPv6 Network Support