Summary
This document describes how to implement NetScalers in a High Availability (HA) pair with redundant switches to protect against switch outages.
Requirements
This article assumes familiarity with configuring NetScalers in an HA pair and configuring port virtual LANs (VLANs) on a switch.
Background
To overcome a switch being a single point of failure in the network, an HA pair can be configured to be physically connected to redundant switches. This addresses the following scenario:
• NetScaler A is connected to switch A
• NetScaler B is connected to switch B
• NetScalers A and B are an HA pair
If both switch A and NetScaler B fail, no traffic can reach the local virtual servers (vservers). To overcome this failure scenario, two links can be used from each NetScaler with each link connected to a different switch.
Using link redundancy, you can group the two interfaces into a Failover Interface Set (FIS), and thus prevent the failure of a single link from causing a failover to the secondary NetScaler unless all interfaces on the primary NetScaler stop functioning.
Procedure
To configure this from the NetScaler Command Line Interface (NSCLI):
1. Disable L2 mode on both NetScalers by issuing the following command:
>disable ns mode L2
2. Create two separate port VLANs on the switch (for example, VLAN 2 and VLAN 3).
3. Enable interfaces 1/1 and 1/2.
4. Connect 1/1 from both NetScalers to VLAN 2.
5. Connect 1/2 from both NetScalers to VLAN 3.
6. Set up an FIS group by using the following commands:
>add fis <set name>
>bind fis <set name> 1/1
>bind fis <set name> 1/2
To configure this from the GUI:
1. Go to System > Global Settings (in release 8.0, this is now called Settings).
2. Select the Modes tab (in release 8.0 this is a link under the heading Modes & Features).
3. Clear the Layer 2 Mode check box.
4. Go to System > High Availability.
5. Select the Failover Interface Set tab.
6. Click Add.
7. Configure the FIS name and move the appropriate interfaces from the Available Interfaces list to the Configured Interfaces list (see the image below).
8. Click Create.
