Submit a ticketCall us

ebook60.pngHow to be a Cisco® ASA ace

Our eBook, Thou Shalt Not Pass…I Think?! can help you overcome the challenges of monitoring and managing Cisco ASA firewalls. This eBook is a great read if you’ve been frustrated with monitoring firewalls, managing ACL configs, and troubleshooting VPN connections.

Get your free eBook.

Home > Success Center > Netflow Traffic Analyzer (NTA) > Not all IP addresses are resolved in NTA via DNS

Not all IP addresses are resolved in NTA via DNS

Updated June 22, 2017


DNS resolution takes a long time to complete or does not fully update every IP address in the environment when Persistent DNS is enabled.


All NTA versions


On-Demand DNS will dynamically resolve all IP addresses on the currently viewed page which usually works better in most cases due to the decreased DNS load and more targeted approach to resolving the most immediately needed nodes. The downside to this option is that some domain name-based reports will no longer work and you will not be able to use some domain name-based search functions.


In addition, there may be some amount of IP addresses that will never resolve if there are no DNS records available for those nodes.


In order to test this, run ping -a from the SolarWinds server to some of these nodes to see if they resolve a reverse DNS record.  Note that while most usage of DNS is a forward lookup (resolve name to IP address), NTA relies on a reverse lookup (resolve IP address to name) instead.


For more information, see the following:


  1. See DNS and NetBIOS resolution to check your NTA settings and see if Persistent DNS is enabled instead of On-Demand DNS.
    Note: If you change DNS resolution to On-Demand, you will lose the functionality of some DNS reports and the ability to search via DNS name.

  2. You can further tune DNS resolution to improve the performance of Persistent DNS if necessary. However, this will be specific to each environment and its available resources. See How does default DNS resolution work in SolarWinds NTA to understand how DNS is resolved in NTA and how to adjust DNS resolution.



Last modified