Migrating DirectAccess from NLB to External Load Balancer


Introduction

Migrating DirectAccess from NLB to External Load BalancerMultiple DirectAccess servers can be deployed in a load-balanced cluster to eliminate single crucial points of failure and to provide scalability for the remote access solution. Load balancing can be enabled using the integrated Windows Network Load Balancing (NLB) or an external physical or virtual load balancer.

NLB Drawbacks and Limitations

NLB is often deployed because it is simple and inexpensive. However, NLB suffers from some serious drawbacks that limit its effectiveness in all but the smallest deployments. For example, NLB uses network broadcasts to communicate cluster heartbeat information. Each node in the cluster sends out a heartbeat message every second, which generates a lot of additional network traffic on the link and reduces performance as more nodes are added. Scalability is limited with NLB too, as only 8 nodes are supported, although the practical limit is 4 nodes. Further, NLB supports only round-robin connection distribution.

External Load Balancer

A better alternative is to implement a dedicated physical or virtual load balancing appliance. A purpose-built load balancer provides additional security, greater scalability (up to 32 nodes per cluster), improved performance, and fine-grained traffic control.

Migrate from NLB to ELB

It is possible to migrate to an external load balancer (ELB) after NLB has already been configured. To do this, follow the guidance provided in my latest blog post on the KEMP Technologies blog entitled “Migrating DirectAccess from NLB to KEMP LoadMaster Load Balancers”.

Migrating DirectAccess from NLB to External Load Balancer

Additional Resources

DirectAccess Deployment Guide for KEMP LoadMaster Load Balancers

Migrating DirectAccess from NLB to KEMP LoadMaster Load Balancers

Load Balancing DirectAccess with KEMP LoadMaster Load Balancers

DirectAccess Load Balancing Tips and Tricks Webinar with KEMP Technologies

DirectAccess Single NIC Load Balancing with KEMP LoadMaster Load Balancer

Configuring the KEMP LoadMaster Load Balancer for DirectAccess NLS

Enable DirectAccess Load Balancing Video

Implementing DirectAccess with Windows Server 2016 Book

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