Dell PowerConnect W Clearpass 100 Software 3.9 Deployment Guide - Page 426

Network Architecture, virtual IP address, Replication

Page 426 highlights

A cluster's virtual IP address is a unique IP address that will always be assigned to the primary node of the cluster. In order to take advantage of the cluster's fault tolerance, all clients that use the cluster must use the cluster's virtual IP address, rather than each node's IP address. Replication is the process of ensuring that the secondary node maintains an exact copy of the primary node's database contents and configuration. Replication is used to ensure that if a failover is required, the secondary node can continue to deliver an uninterrupted service to clients of the cluster. See "About High Availability Systems" for the following settings and procedure..  Keep-alive  Database replication.  Configuration replication  Downtime threshold Network Architecture The figure below shows the network architecture for a high availability cluster. Figure 50 Network architecture of high availability cluster The key points to note about this architecture are:  The RADIUS and Web server protocols (HTTP and HTTPS) are supported by the cluster.  The cluster has three IP addresses: each node has its own IP address, and there is a virtual IP address for the cluster which will always be assigned to the primary node in the cluster.  For the cluster to provide failover redundancy, all network access servers and operators must use the cluster's IP address.  The network administrator should use the node IP addresses to perform system administration tasks on each node, including managing the cluster itself.  The cluster relies on DNS for name lookup. Each node must have a unique hostname, and each node must be able to resolve the other node's IP address by performing a DNS lookup. The nodes in the cluster must be connected to the same local network. Use high quality network cables and reliable switching equipment to ensure the nodes have an uninterrupted network connection. 426 | High Availability Services ClearPass Guest 3.9 | Deployment Guide

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426
|
High Availability Services
ClearPass Guest 3.9
|
Deployment Guide
A cluster’s
virtual IP address
is a unique IP address that will always be assigned to the primary node of the
cluster. In order to take advantage of the cluster’s fault tolerance, all clients that use the cluster must use
the cluster’s virtual IP address, rather than each node’s IP address.
Replication
is the process of ensuring that the secondary node maintains an exact copy of the primary
node’s database contents and configuration. Replication is used to ensure that if a failover is required, the
secondary node can continue to deliver an uninterrupted service to clients of the cluster.
See
“About High Availability Systems”
for the following settings and procedure..
Keep-alive
Database replication.
Configuration replication
Downtime threshold
Network Architecture
The figure below shows the network architecture for a high availability cluster.
Figure 50
Network architecture of high availability cluster
The key points to note about this architecture are:
The RADIUS and Web server protocols (HTTP and HTTPS) are supported by the cluster.
The cluster has three IP addresses: each node has its own IP address, and there is a virtual IP address for
the cluster which will always be assigned to the primary node in the cluster.
For the cluster to provide failover redundancy, all network access servers and operators must use the
cluster’s IP address.
The network administrator should use the node IP addresses to perform system administration tasks on
each node, including managing the cluster itself.
The cluster relies on DNS for name lookup. Each node must have a unique hostname, and each node
must be able to resolve the other node’s IP address by performing a DNS lookup.
The nodes in the cluster must be connected to the same local network. Use high quality network cables and
reliable switching equipment to ensure the nodes have an uninterrupted network connection.