In the first part of NSX-T Distributed Firewall, I explained the importance of embracing NSX-T DFW. In this post, I review how you can create and apply firewall rules to implement Micro-segmentation. To create firewall rules, first you need to define a Policy section which basically contains one or more firewall rules. A policy in NSX-T DFW can be defined as stateful or stateless. In the case of being stateless, you need to define the rules in both directions. Otherwise, the reverse traffic is not allowed to pass. On the other hand, in the default stateful mode, when you define a rule it will apply bidirectionally.
Then you need to define the rules under the policy section which evaluates the criteria of a traffic flow. DFW rules determine whether the traffic should pass or get dropped based on the protocol and ports.
NSX-T Distributed Firewall (DFW) is one of the most comprehensive solutions to provide micro-segmentation from layer 4 to layer 7. It can monitor all the East-West traffic on your virtual machines and build a Zero-trust model. To leverage the DFW, vNIC of virtual machines need to connect to NSX-overlay segment, NSX VLAN backed segments or vDS port group supported from vSphere 7.0. The benefit of using DFW is that firewall rules apply at the vNIC level of virtual machines. In this way, traffic does not need to traverse to a physical firewall to get identified if the traffic can pass or drop, which is more efficient. This article will focus on using DFW to enforce L7 (FQDN/URLs) filtering.
You can give internet access to a VM or a user who login to a VM by Identity Based Firewall or even take one step further and control which specific URL/URLs are allowed to get accessed.
Before jumping to NSX-T Distributed Firewall (DFW) concept and rule creation, I want to point out why this solution is important and what security issues can be addressed by using this powerful solution. Building a zero trust model security has been the biggest concern of network and security teams. In traditional data centers, high-level segmentation is built, which could help to prevent various types of the workload from communicating. But the main challenge of the legacy security model is data centers facing a lack of lateral prevention communication system between workloads within a tier. In other words, traffic can traverse freely inside a network segment and access the crucial information until it reaches the physical firewall to get dropped. In addition, implementing different layers of security and firewalls would cause complexity and cost.
NSX-T Distributed Firewall (DFW) is a hypervisor kernel-based firewall that monitors all the East-West traffic and could be applied to individual workloads like VM and enforce zero-Trust security model. Micro-segmentation logically divides department or set of applications into security segments and distribute firewalls to each VM.
In the previous articles, we deployed first NSX-T Manager and then we added vCenter Server as Compute Manager in NSX-T Web UI. In this post we are going to finalize NSX-T Management cluster. In production environment for high availability and performance reasons, it is recommended to have three NSX-T Managers in the cluster. Second and third NSX-T Managers should be added from NSX-T Web UI. To deploy additional NSX-T manager appliances, go to System menu and choose Appliances and click on “ADD NSX APPLIANCE”.
In previous blog post we started NSX-T implementation by deploying first NSX-T Manager. Before deploying other two NSX-T Managers we need to add a Compute Manager. As it defines by VMware, “A Compute Manager is an application that manage resources such as hosts and VMs. One example is vCenter Server”. We do this because other NSX-T Managers will be deployed through Web UI and with help of vCenter Server. We can add up to 16 vCenter Servers in a NSX-T Management cluster.
To add compute manager in NSX-T, It is recommended to create a service account and customized vSphere Role instead of using NSX-T default admin account. The reason behind defining a specific role is because of security reasons. As you can see in the below screen shot I created a vSphere Role call “NSX-T Compute Manager” with the required privileges. I use this Role to assign permission to the service account on vCenter Server.
As it mentioned in Introduction to VMware NSX , NSX-T Datacenter is built on three integrated layers of components which are Management Plane, Control plane & Data plane. This architecture and separation of key roles enables scalability without impacting workloads.
NSX-T Management cluster which built from three-node NSX-T managers controller nodes. Management plane and control plane are converged on each node. NSX managers provides Web-GUI and REST API for management purposes. This is one of the architectural difference compared to NSX-V which had to integrate into vSphere Client & vCenter server. NSX Manager is also could be consumed by Cloud Management Platform(CMP) like vRealize Automation to integrate SDN into cloud automation platforms. NSX-T Manager can also connect to vSphere infrastructure through integration with vCenter Server(Compute Manager).
NSX-T has a default password expiration policy of 90 days for NSX-T Manager and NSX-T Edges. As soon as this expiration period passes, at the login page of NSX-T Manager an error appears complaining that “Your password has expired”. As a result, you are not able to login to NSX-T Manager.
To solve this issue, login to NSX Manager’s virtual appliance through SSH. Enter admin as the username and use current password to login. After login in NSX Manager, you will be asked to change your password because it is expired. This is the way you can reset NSX Manager admin’s password.
VMware NSX is a network
virtualization and security platform and it is part of VMware’s Software Define
Datacenter (SDDC) architecture. VMware NSX has emerged as VMware acquisition of
a company call Nicira in 2012 which had a solid product on Software Defined
Network (SDN). The product comes in four different forms;
NSX Data Center
NSX Hybrid Connect
NSX Data Center itself comes
in two different flavors, NSX-V which mainly designed to work in VMware vSphere
environments and NSX-T, formerly known as Multi-Hypervisor, which offers
network virtualization and cyber-security features for multi-hypervisor,
container-based and multi-cloud environments like AWS or Azure cloud services.
Software-Defined networking delivers L2 to L7 network functions in software and
allowing virtualization and cloud administrators to provision required services
on hypervisor level.