HP Serviceguard manual Network Configuration Restrictions

All Node Addresses = FF02:0:0:0:0:0:0:1 (link-local)

All Router Addresses = FF02:0:0:0:0:0:0:2 (link-local)

All Router Addresses = FF05:0:0:0:0:0:0:2 (site-local)

Network Configuration Restrictions

Serviceguard supports IPv6 for data and heartbeat IP.

To configure IPv6, the system should be set up in what is called a dual-stack configuration, which requires the IPv6 product bundle.

The restrictions for supporting IPv6 in Serviceguard are listed below.

•Auto-configured IPv6 addresses are not supported in Serviceguard as HEARTBEAT_IP or STATIONARY_IP addresses. IPv6 addresses that are part of a Serviceguard cluster configuration must not be auto-configured through router advertisements, for example. They must be manually configured in /etc/rc.config.d/netconf-ipv6.

• Link-local IP addresses are not supported, as package IPs, HEARTBEAT_IPs, or STATIONARY_IPs. Depending on the requirements, the package IP could be of type site-local or global.

•Serviceguard supports only one IPv6 address belonging to each scope type (site-local and global) on each network interface (that is, restricted multi-netting). Therefore, up to a maximum of two IPv6 STATIONARY_IPs or HEARTBEAT_IPs can be mentioned in the cluster configuration file for a NETWORK_INTERFACE: one being the site-local IPv6 address, and the other being the global IPv6 address.

NOTE: This restriction applies to cluster configuration, not package configuration: it does not affect the number of IPv6 relocatable addresses of the same scope type (site-local or global) that a package can use on an interface.

•Serviceguard supports IPv6 only on the Ethernet networks, including 10BT, 100BT, and Gigabit Ethernet

NOTE: Even though link-local IP addresses are not supported in the Serviceguard cluster configuration, the primary link-local address on the Serviceguard primary interface will be switched over the standby during a local switch. This is because of two requirements: First, the dual stack (IPv4/IPv6) kernel requires that the primary IP address associated with an interface must always be a link-local address. Second, Serviceguard requires that the site-local and global IPs be switched to the standby network interface.

IPv6 Relocatable Address and Duplicate Address Detection Feature

The IPv6 networking stack has a new feature, Duplicate Address Detection (DAD), that was not previously available in IPv4. When an address is being added, the DAD detects a duplicate address that is already being used on the network. It sends out a multicast message to the network neighborhood, and requires at least one second to listen for responses from other nodes. If no responses are received in that time, the relocatable IPv6 address is considered free to use. For more information regarding this feature, please refer to the RFC 2462.

The effect of this feature on Serviceguard is that the time required to add each IPv6 relocatable address will be at least one second longer than adding a corresponding IPv4 address. Depending on the number of IPv6 addresses configured within a package, this could have a moderate to significant impact on package start time.

If you do not need duplicate address detection, you can disable the DAD feature by setting the kernel parameter ip6_nd_dad_solicity_count to 0. Please note that this kernel parameter applies to the entire system. If you turn it off, you disable it for all applications on the system. For systems where DAD is not required, disabling this feature can significantly improve the start time of package packages containing a large number of IPv6 relocatable addresses.

To determine the current state of DAD on your system, use the ndd -getcommand to see the current value of the kernel parameter.

Network Configuration Restrictions 381