DHCP snooping is a security feature intended to prevent rogue DHCP server from sending malicious DHCP replies. When DHCP snooping is enabled, the switch intercept all the DHCP requests, and discards DHCP replies coming from “untrusted” ports. The offending switch…
How Private VLANs Work?

It’s simple to explain What Private VLAN is, but Cisco’s implemenation and configuration steps are a bit confusing – with all the “mappings” and “associations” stuff. Here we will talk about Private VLAN and how private VLANs work. Firstly, let’s…

Many installers make the mistake of treating 802.11 WLANs just like Ethernet, placing access points (APs) in locations that facilitate outsider access to corporate networks. But, from a security perspective, WLANs should be treated like the Internet — a network…
How to Troubleshoot OSPF?

OSPF is one of our more complicated routing protocols, and it can be pretty intimidating, especially at first. But once you have mastered how to configure this Link State Protocol, the first thing you realize is that it is built…