Many admins inadvertently design a sinkhole by null routing unused ranges within their core in order to limit unnecessary traffic. Some may even advertise these ranges from a Linux server running zebra or quagga for advanced alerting while monitoring for the propagation of worms or enumeration scans. In this post, we will discuss a similar idea for DNS using Firepower.
Continue reading FIREPOWER DNS Sinkhole
Sometimes you may want to quickly block a scanning/probing IP address without having to deal directly with the Access Control Policy. This can be done in the FMC within the Events view. Go to Analysis -> Connections -> Events
Depending on volume of traffic, you may have to click ‘Edit Search‘ and look by Initiator or Responder IP. Once found, right-click on the IP address and select ‘Blacklist IP Now‘ and confirm,
Continue reading Blacklist an IP in Firepower
The Network Logician 