User manual

Hot Standby
33002479 06 07/2008 317
Power Up and IP
Address
Assignment
An NOE obtains its IP address assignment at power up as follows:
If two NOEs power up simultaneously, a resolution algorithm:
z determines the primary CPU NOE
z assigns the configured IP address to that primary CPU NOE
z assigns the configured IP address + 1 to the secondary NOE
The NOE performs a duplicate IP test by issuing an ARP request to the configured
IP address. If a response is received within 3 seconds, the IP address remains at
the default IP and blinks a diagnostic code.
If no IP configuration exists, the NOE remains in standalone mode, and the IP
address must be obtained from either a BOOTP server or a MAC address.
If the HSBY state is ... Then the IP address assigned is ...
unassigned configured IP address
primary CPU configured IP address
secondary configured IP address + 1
unassigned to offline See the Offline Mode at Power-up Sequence in the next table.
Offline Mode at Power-up Sequence Result
Controller A powers-up before controller
B
z IP address of controller A is the configured IP
address
z IP address of controller B is the configured IP
address + 1
Both controller A and controller B power-
up at the same time
The resolution algorithm will assign controller A
the configured IP address, and it will assign
controller B the configured IP address + 1.