Apple Mac OS X Server (version 10.2.3 or later) - Manual (Page 609)

Tools for Advanced Administrators 609
Enabling IP Failover
You enable IP failover by adding command lines to the file /etc/hostconfig on the primary
and the secondary server. Be sure to enter these lines exactly as shown with regard to spaces
and punctuation marks.
To enable IP failover:
1 At the primary server, add the following line to /etc/hostconfig:
FAILOVER_BCAST_IPS=”10.0.0.255 100.0.255.255”
Substitute the broadcast addresses used on your server for the public and private networks.
This tells the server to send broadcast messages over relevant network interfaces that the
server at those IP addresses is functioning.
2 Restart the primary server so that your changes can take effect.
3 Disconnect the primary server from both the public and private networks.
4 At the secondary server, add the following lines to /etc/hostconfig:
FAILOVER_PEER_IP=”10.0.0.1”
FAILOVER_PEER_IP_PAIRS=”en0:100.0.0.10”
FAILOVER_EMAIL_RECIPIENT=”[email protected]”
In the first line substitute the IP address of the primary server on the private network.
In the second line enter the local network interface that should adopt the primary server’s
public IP address, a colon, then the primary server’s public IP address.
(Optional) In the third line, enter the email address for notification messages regarding the
primary server status. If this line is omitted, email notifications are sent to the root account
on the local machine.
5 If you wish to receive email notifications, verify that MailServer is enabled in your /etc/
hostconfig file. If the entry reads:
MAILSERVER=-NO-
Change to:
MAILSERVER=-YES-
6 Restart the secondary server so that your changes can take effect and allow the secondary
server to acquire the primary’s public IP address.
Important
Before enabling IP Failover, verify on both servers that the port used for the
public network appears at the top of the Network Port Configurations list in the Network
pane of System Preferences. Also verify that the port used for the private network contains
no DNS configuration information. This ensures DNS lookups function properly.
LL0395.Book Page 609 Wednesday, November 20, 2002 11:44 AM