When you configure
NetScaler Gateway in a high availability pair, the secondary NetScaler Gateway
monitors the first appliance by sending periodic messages, also called a heartbeat
check, to determine if the first appliance is accepting
connections. If a health check fails, the secondary NetScaler Gateway tries the
connection again for a specified amount of time until it determines that the
primary appliance is not working. If the secondary appliance confirms the
health check failure, the secondary NetScaler Gateway takes over for the
primary NetScaler Gateway. This is called
The following ports
are used to exchange information related to high availability between NetScaler
configuring a high availability pair, you should review these guidelines:
- Each NetScaler Gateway
appliance must be running the same version of the NetScaler Gateway software.
You can find the version number at the top of the page in the configuration
- NetScaler Gateway does not
automatically synchronize passwords between two appliances. You can choose to
configure each NetScaler Gateway with the user name and password of the other
appliance in the pair.
- Entries in the
configuration file, ns.conf, on both the primary and the secondary NetScaler
Gateway must match, with the following exceptions:
- The primary and secondary
NetScaler Gateway appliance must each be configured with its own unique system
IP address. Use the Setup Wizard to configure or modify the system IP address
on either NetScaler Gateway.
- In a high availability
pair, the NetScaler Gateway ID and associated IP address must point to the
other NetScaler Gateway.
example, if you have two appliances, named AG1 and AG2, you must configure AG1
with the unique NetScaler Gateway ID and IP address of AG2. You must configure
AG2 with the unique NetScaler Gateway ID and IP address of AG1.
NetScaler Gateway appliance are always identified as Node 0. Configure each
appliance with a unique node ID.
- Each appliance in the high
availability pair must have the same license. For more information about
licensing, see Licensing NetScaler Gateway.
- If you create a
configuration file on either node by using a method that does not go directly
through the configuration utility or the command-line interface (for example,
importing SSL certificates, or changing to startup scripts), you must copy the
configuration file to the other node or create an identical file on that node.
- When you configure a high
availability pair, make sure the mapped IP addresses and default gateway
address of both the primary and the secondary appliances are identical. If
necessary, you can change the mapped IP address at any time by running the
Setup Wizard. For more information, see
Initial Settings by Using the Setup Wizard.
You can use the
pre-installation checklist to view a list of the specific settings you need to
configure in a high availability deployment, For details, see NetScaler Gateway Pre-Installation Checklist.