Trending Topics

VMware on AWS - How to restore NSX DFW firewall rules to previous state

Image
Customers who uses NSX day-in, day-out would like to have a point-in time restore functionality of DFW firewall rules. Many customer have a large footprints in VMC and make changes to DFW quite often. This feature was missing for long time and we could see its included in recent versions . Let's see how DFW configuration roll back works  NSX DFW configuration has versioning, and it is stored in the NSX Manager.  Every time when someone update DFW configuration, NSX creates one more version but keep storing the previous ones. You can rollback for previous config but reapplying it once again.  You can find the options under Networking & Security tab , > Security > Distributed Firewall . In the right side we see an Actions drop down. Choose View to get to the below screen.  Let’s go through the use case:  1. Original state- default config with no custom rules:  a. There are no saved configurations during last 30 days: In my existing test setup, with the current setting

port knocking

A method of establishing a connection to a securednetwork or computer within a network that does not have an open port. Aremote device sends a series of series of connection attempts, in the form ofpackets, to the computer??s closed ports, and the attempts are silently ignored but logged by the firewall. When the remote device has established the predetermined sequence of port connection attempts, a daemon triggersa port to open, and the network connection is established. This security method is analogous to knowing a "secret knock," and only people who know the proper knock sequence will be allowed access. An advantage of using a port knocking technique is that a malicious hacker cannot detect if a device is listening for port knocks.

Popular posts from this blog

HOW TO EDIT THE BCD REGISTRY FILE

Image
The BCD registry file controls which operating system installation starts and how long the boot manager waits before starting Windows. Basically, it’s like the Boot.ini file in earlier versions of Windows. If you need to edit it, the easiest way is to use the Startup And Recovery tool from within Vista. Just follow these steps: 1. Click Start. Right-click Computer, and then click Properties. 2. Click Advanced System Settings. 3. On the Advanced tab, under Startup and Recovery, click Settings. 4. Click the Default Operating System list, and edit other startup settings. Then, click OK. Same as Windows XP, right? But you’re probably not here because you couldn’t find that dialog box. You’re probably here because Windows Vista won’t start. In that case, you shouldn’t even worry about editing the BCD. Just run Startup Repair, and let the tool do what it’s supposed to. If you’re an advanced user, like an IT guy, you might want to edit the BCD file yourself. You can do this
Read more

DNS Scavenging.

                        DNS Scavenging is a great answer to a problem that has been nagging everyone since RFC 2136 came out way back in 1997.  Despite many clever methods of ensuring that clients and DHCP servers that perform dynamic updates clean up after themselves sometimes DNS can get messy.  Remember that old test server that you built two years ago that caught fire before it could be used?  Probably not.  DNS still remembers it though.  There are two big issues with DNS scavenging that seem to come up a lot: "I'm hitting this 'scavenge now' button like a snare drum and nothing is happening.  Why?" or "I woke up this morning, my DNS zones are nearly empty and Active Directory is sitting in a corner rocking back and forth crying.  What happened?" This post should help us figure out when the first issue will happen and completely avoid the second.  We'll go through how scavenging is setup then I'll give you my best practices.  Scavenging s
Read more

AD LDS – Syncronizing AD LDS with Active Directory

Image
First, we will install the AD LDS Instance: 1. Create and AD LDS instance by clicking Start -> Administrative Tools -> Active Directory Lightweight Directory Services Setup Wizard. The Setup Wizard appears. 2. Click Next . The Setup Options dialog box appears. For the sake of this guide, a unique instance will be the primary focus. I will have a separate post regarding AD LDS replication at some point in the near future. 3. Select A unique instance . 4. Click Next and the Instance Name dialog box appears. The instance name will help you identify and differentiate it from other instances that you may have installed on the same end point. The instance name will be listed in the data directory for the instance as well as in the Add or Remove Programs snap-in. 5. Enter a unique instance name, for example IDG. 6. Click Next to display the Ports configuration dialog box. 7. Leave ports at their default values unless you have conflicts with the default values. 8. Click N
Read more