Linksets must be used when some cluster nodes are not physically connected to the external network. In such a cluster topology, the unconnected cluster nodes use the interfaces specified in the linkset to communicate with the external network through the cluster backplane. Linksets are typically used in scenarios when the connecting devices have insufficient ports to connect the cluster nodes.
Linksets are a mandatory configuration in the following scenarios:
- For deployments that require MAC-Based Forwarding (MBF).
- For “-m MAC” mode that is enabled at the virtual server along with MBF mode enabled globally.
- To improve the manageability of ACL and L2 policies involving interfaces. You define a linkset of the interfaces and add ACL and L2 policies based on linksets.
Linksets must be configured only through the cluster IP address.
For example, consider a three node cluster where the upstream switch has only two ports available. Using linksets, you can connect two nodes to the switch and leave the third node unconnected. In the following figure, a linkset (LS/1) is formed by binding the interfaces 0/1/2 and 1/1/2. NS2 is the unconnected node of the cluster.
Figure 1. Linksets topology
The linkset informs NS2 that it can use interfaces 0/1/2 and 1/1/2 to communicate with the network devices. All traffic to and from NS2 is now routed through interfaces 0/1/2 or 1/1/2.
Figure 2. Traffic distribution flow using linksets
To configure a linkset by using the command line interface
Log on to the cluster IP address.
Create a linkset.
add linkset <id>
add linkset LS/1
Bind the required interfaces to the linkset. Make sure the interfaces are not used for the cluster backplane.
bind linkset <id> -ifnum <interface_name> ...
bind linkset LS/1 -ifnum 0/1/2 1/1/2
Verify the linkset configurations.
show linkset <id>
show linkset LS/1
You can bind the linkset to a VLAN by using the “bind vlan” command. The interfaces of the linkset are automatically bound to the VLAN.
To configure a linkset by using the configuration utility
- Log on to the cluster IP address.
- Navigate to System > Network > Linksets.
- In the details pane, click Add.
- In the Create Linkset dialog box:
- Specify the name of the linkset by setting the Linkset parameter.
- Specify the Interfaces to be added to the linkset and click Add. Repeat this step for each interface you want to add to the linkset.
- Click Create, and then click Close.