0
In the last post, VMware NSX™ Distributed Firewall installation and operation was verified. In this entry, the FTP (file transfer protocol) ALG (Application Level Gateway) is tested for associating data connections with originating control connections – something a stateless ACL (access control list) can’t do.
An added benefit over stateless ACLs – most compliance standards more easily recognize a stateful inspection-based firewall for access control requirements.
To check ALG support for a particular NSX version, refer to the VMware NSX Administration manual. VMware NSX version 6.2 supports FTP, CIFS, ORACLE TNS, MS-RPC, and SUN-RPC ALGs. Do expect additional ALG protocol support with future versions of NSX.
Assuming a default firewall rulebase for simplicity, and a basic setup:
- three ESXi vSphere 6.0 hosts in a cluster
- NSX installed, with the NSX Manager installed on the first host
- two guest VMs running Centos: one running an FTP server, the other an FTP client
Simplified diagram, along with connections for the following test:

Previously, an ESXi host command line was used to interact with the Distributed Firewall. Here, the NSX Manager Central CLI – a new option with NSX 6.2 – is used. Slightly different incantations, but the same results can be Continue reading