Showing posts from December, 2019

Faster Log Insight Responses for NSX Firewall Source/Destination IP Queries

We've been doing a lot of work with the NSX Firewall recently.  Log Insight has become our go-to tool for troubleshooting to get real-time information about what the firewall is doing.  By far, the most common query that I run in Log Insight will be for all entries that have a vmw_nsx_firewall_src or vmw_nsx_firewall_dst of the IP Address that I'm interested in, and I'll often throw a vmw_nsx_firewall_dst_port or a vmw_nsx_firewall_action into the mix to further refine my results.

Unfortunately, these queries can be pretty slow.  They're great if you're looking at the last 5 minutes worth of data, and they're pretty good going back to the past hour... but when we went beyond a 1 hour window, we found ourselves needing to wait.  If we wanted to go all the way out to a 24 hour window, we'd need to go get lunch while the query ran.  That seemed unreasonable to us, so we opened a support ticket and the VMware engineer made some tweaks that absolutely helped, bu…

Using the vRNI API through PowerShell

I've been plugging away with vRNI and the NSX Distributed firewall a lot, but that hasn't generally leant itself well to writing blog posts... until recently!  We are working on an auditing process to help us decommission NSX firewall rules in favor of policies.  Typically, when retiring a firewall rule, you would just change its priority so that it's below the newer Allow rules but still above the Deny rules, then wait a while and see if it still gets any hits.  In this situation, we're looking to retire some manually created firewall rules in favor of our new set of policy-driven rules, and you can't put manual rules in the middle of your policy rules... so the typical firewall procedure won't work here!
So, we've been working on a process to use vRNI to look at all traffic that's hitting a given firewall rule, then check on the policy-based rules and ensure that it will all be allowed by those rules.  The process itself is pretty simple, and looks li…