The basic syntax of an IPaddr2 resource is
So, the following forms of addressing are legal:
IPaddr2::address IPaddr2::address/netmask IPaddr2::address/netmask/broadcast IPaddr2::address/netmask/interface IPaddr2::address/netmask/interface/broadcast
By far the most common case is the simplest one:
In this form, appropriate defaults are taken as described below.
If the interface was omitted, we use the system routing tables to determine which interface would be used to route a packet to the given address. That is, IPaddr2 selects the preferred interface for sending packets to that subnet. If no such interface can be found, heartbeat will issue a message something like this:
ERROR: unable to find an interface for given-ip-address
If the CIDR netmask is omitted, we choose the netmask associated with the route to the subnet to which packets to the given IP address would be routed. That is, we simply look up the routing information for that address, and use it to compute the correct netmask (and other items as described below).
If the broadcast address was omitted, IPaddr2 defaults to the highest address in the subnet (the usual default).
IPaddr2::188.8.131.52 IPaddr2::184.108.40.206/24 (implies a 255.255.255.0 netmask) IPaddr2::220.127.116.11/24/18.104.22.168 IPaddr2::22.214.171.124/24/eth0 IPaddr2::126.96.36.199/24/eth0/188.8.131.52
The interface mentioned above does not include an alias number. Heartbeat assigns them dynamically according to the available alias names.
See http://www.doom.net/docs/netmask.html for a table explaining CIDR address format and their relationship to life, the universe and everything.
Unlike IPaddr, IPaddr2 has no obvious limitations on the number of addresses it can configure on an interface.