C H A P T E R 12

Replication and High Availability

To provide high availability, the Cisco NAC Guest Server solution can be configured so that a pair of units synchronize their databases between one another. This provides the ability for the solution to carry on working in the event of loss of connectivity or failure to a single unit.

High availability is provided in an active/active scenario, where both Cisco NAC Guest Servers can service requests from sponsors or network devices at the same time. This capability also allows you to load balance the requests between the boxes.

Note For load balancing external load balancers must be used to load balance the web interface. RADIUS requests can also be load balanced via external load balancers or by configuration.

This chapter includes the following sections:

Setting up replication

Configuring Provisioning

Replication Status

Recovering from Failures

Deployment Considerations

Setting up replication

Initial replication is configured by setting one of the Cisco NAC Guest Servers to copy all of the data from the other Guest Server. The Guest Server that is configured to copy the data from the other device will be first set to delete all its own data. This ensures that no conflicts exist. Cisco recommends setting up replication at initial install time of Cisco NAC Guest Server, or when adding a new Guest Server to an existing implementation.

Warning All Data on one of the Guest Servers will be overwritten. If you have data that is needed on both Guest Servers then you should not configure replication as you will loose data.

Once one of the Guest Servers has received a copy of the data from the other device they are synchronized and replication is turned on. Any data that is updated on one Guest Server is then automatically replicated to the other Guest Server.

All communication between the Cisco NAC Guest Servers is encrypted using SSL and runs over TCP destination port 5432.

 

 

Cisco NAC Guest Server Installation and Configuration Guide

 

 

 

 

 

 

 

OL-15986-01

 

 

12-1

 

 

 

 

 

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Cisco Systems OL-15986-01 manual Replication and High Availability, Setting up replication, 12-1

OL-15986-01 specifications

Cisco Systems OL-15986-01 refers to a specific online training course offered by Cisco, primarily focusing on the implementation and configuration of Cisco routers and switches. This course is part of the larger Cisco Networking Academy program, designed to equip individuals with the necessary skills to enter and succeed in the networking field.

One of the main features of OL-15986-01 is its comprehensive curriculum that covers a wide range of networking concepts including IP addressing, routing protocols, switching technologies, and network management. The coursework emphasizes practical, hands-on experience, allowing students to work with various Cisco technologies, whether through simulations or actual equipment. This aligns with Cisco's commitment to experiential learning, enabling students to apply theoretical knowledge in real-world scenarios.

The course also incorporates advanced technologies and methodologies. For example, it delves into IPv6 addressing and its significance in modern networking, alongside traditional IPv4. Routing protocols such as OSPF, EIGRP, and BGP are discussed in detail, providing learners with insights into how data is routed efficiently across different networks. Additionally, the course covers switching technologies, including VLANs, STP, and EtherChannel, which are essential for configuring robust and efficient local area networks (LANs).

Another noteworthy characteristic of OL-15986-01 is its focus on network security. Students learn about the vulnerabilities that networks face and how to implement security measures to protect network infrastructure. Topics include secure access methods, firewall configurations, and the use of VPNs for secure remote access.

Furthermore, the course emphasizes troubleshooting techniques, empowering students with the skills to identify and resolve network issues effectively. Practical lab sessions and assessments allow learners to demonstrate their comprehension of networking principles and their ability to apply them in various situations.

Ultimately, Cisco Systems OL-15986-01 is designed for individuals seeking to boost their networking knowledge and skillset, paving the way for careers in IT infrastructure management, network engineering, and other technology-related fields. By completing this course, participants gain a solid foundation in networking that can lead to valuable Cisco certifications, enhancing their professional credibility in a competitive job market.