Network Services

Load balancing is the foundational technology of any scale-out application architecture. This section describes a wide variety of load balancing approaches, from server-based technologies to dedicated load balancing appliances.

This section introduces the concepts and terminology:

• Many levels of firewall statefulness
• Differences between virtual firewalls and contexts on physical firewalls;
• Virtual firewall taxonomy (from appliances to VM NIC firewalls)

Numerous virtual firewalls are nothing more than traditional firewalling software running within a virtual machine. This section describes the benefits and drawbacks of moving from physical appliances to virtual firewall appliances.

VM NIC firewalls are solutions that filter traffic between a virtual machine and adjacent virtual switch. This section describes several VM NIC firewall implementation models and the tradeoffs they're making.

You could implement security functionality in virtualized environment with service insertion: redirecting the traffic through a security appliance (physical or virtual).

After mastering the load balancing and firewalling concepts we're ready to use them in a data center design.

The network services elements you should use depend on the services your infrastructure has to offer, and the amount of self-service you want to offer to your customers - the more self-sufficient you want your customers to be, the more you should utilize per-tenant virtual appliances.

In one of the live sessions of 2017 course we discussed whether to use distributed (in-kernel) firewalls or virtual appliances.

These ipSpace.net webinars describe topics related to this module. Some of them have been included in the recommended or optional self-study materials; you might want to watch all of them.