Primary IP address of the corresponding node. This value
is taken from the PNNI Nodal PTSE. The primary IP address is
used by the NMS to manage the switch. The type of interface
(i.e. ATM interface, LAN interface, etc) for this IP address
is specified by cwtPrimIPIfType. The NMS will use this IP
address first, but if it can not connect to the switch on
this address, then it will try to contact the switch using
the secondary IP address instead.