High Availability VPN Failover Configuration With MikroTik Routers

Clientless SSL VPN is a crucial tool for securing remote access to the corporate network. It enables employees to access resources from any web-enabled device while minimizing the risk of security breaches. High availability in clientless SSL VPN is a necessary feature for ensuring seamless access to critical resources.

In this article, we will delve deeper into the concept of high availability in clientless SSL VPN and explain why it is essential for any organization. Here are some key points:

Ensuring High Availability

In today's interconnected world, organizations rely heavily on the internet to access critical resources, applications, and systems. In a clientless SSL VPN environment, the primary concern is the availability of resources. To ensure that resources remain available at all times, high availability is a critical requirement.

High availability ensures that there is no single point of failure in the system, reducing the risk of downtime and increasing availability. Organizations can achieve high availability through several means, including:

Load Balancing: Load balancing spreads the traffic across multiple systems, ensuring that no single system becomes overwhelmed. Load balancing can be achieved through dedicated hardware devices or software-based solutions that run on commodity hardware.
Redundancy: Redundancy involves having a backup system ready to take over in case the primary system fails. Organizations can implement redundancy through active-passive systems where the standby system is inactive until it needs to take over.
Clustering: Clustering involves having multiple systems work together as a single unit. In a clustered environment, if one system fails, the others take over, ensuring continuity of service.

These mechanisms ensure that if one system fails, the other systems take over, ensuring that resource availability is maintained at all times.

Load Balancing

Load balancing is a mechanism that distributes incoming network traffic across multiple servers. Load balancing can be implemented using hardware or software solutions.

In a clientless SSL VPN environment, load balancing ensures that if one system becomes overloaded or fails, incoming traffic is distributed across the other servers, ensuring that resource availability is maintained at all times.

Two types of load balancing mechanisms are commonly used:

Round-Robin Load Balancing: In round-robin load balancing, incoming requests are distributed equally across all the available servers. For example, if an organization has three clientless SSL VPN servers, incoming requests would be distributed as follows: Server 1, Server 2, Server 3, Server 1, Server 2, Server 3, and so on.
Weighted Load Balancing: In weighted load balancing, incoming requests are distributed proportionally to the capacity of each server. For example, if Server 1 has twice the capacity of Server 2, incoming requests would be distributed as follows: Server 1, Server 1, Server 2, Server 1, Server 1, Server 2, and so on.

Load balancing, when implemented correctly, can significantly improve resource availability, ensuring that users can access critical applications and data at all times.

Redundancy

Redundancy is a mechanism that involves having a backup system ready to take over in case the primary system fails. In a clientless SSL VPN environment, redundancy ensures that if the primary server fails, the standby server takes over, ensuring that resource availability is maintained at all times.

The two main types of redundancy are active-passive and active-active:

Active-Passive: In an active-passive configuration, the primary server is active, while the standby server is passive. If the primary server fails, the standby server takes over. However, only one server is active at any given time, resulting in underutilization of resources.
Active-Active: In an active-active configuration, both servers are actively processing incoming requests, with one server acting as the primary server, and the other server acting as a standby server. If the primary server fails, the standby server takes over seamlessly, ensuring that there is no disruption in service. This configuration maximizes resource utilization.

Redundancy ensures that there is no single point of failure in the system, reducing the risk of downtime and increasing availability.

Clustering

Clustering involves having multiple systems work together as a single unit. In a clientless SSL VPN environment, clustering ensures that if one system fails, the other systems take over seamlessly, ensuring resource availability is maintained at all times.

Clustering can be implemented using two primary mechanisms:

Active-Passive: In an active-passive configuration, only one node is active at any given time, with the other nodes in standby mode. If the active node fails, one of the standby nodes takes over, ensuring continuity of service.
Active-Active: In an active-active configuration, all the nodes are actively processing incoming requests, ensuring that there is no underutilization of resources. If one node fails, the other nodes take over seamlessly, ensuring that resource availability is maintained.

Clustering ensures that there is no single point of failure in the system, reducing the risk of downtime and increasing availability.

In conclusion

High availability is a crucial feature for any clientless SSL VPN solution. It ensures that there is no single point of failure in the system, reducing the risk of downtime and increasing availability.

Organizations can achieve high availability through several mechanisms, including load balancing, redundancy, and clustering. Each mechanism has its benefits and drawbacks, and organizations need to choose the mechanism that best fits their needs.

High availability is critical for organizations that rely heavily on the internet to access critical resources, applications, and systems. Implementing high availability ensures continuity of service, reduces the risk of security breaches, and helps organizations meet their business objectives.