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…
VLAN Trunking Protocol (VTP) & VTP Modes

What is a VLAN Trunking Protocol (VTP)? “VTP allows a network manager to configure a switch so that it will propagate VLAN configurations to other switches in the network” VLAN Trunking Protocol (VTP) is a Cisco proprietary Layer 2 messaging…
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…
How to Connect Cisco IP Phones?

When you buy all Cisco IP phones, without the power adaptor, so how to work? There are 3 options for connections. 1) Buy power transformer (CP-PWR-CUBE-3) directly; suitable for few Qty, will be an economic method. 2) If you have…

Cisco IOS Command Summary—Four Modes to Access and Configure a Cisco Router The four modes for accessing and configuring a Cisco router are: user EXEC mode, privileged EXEC mode, global configuration mode, interface configuration mode Each mode has a unique command set. Purpose of…
How to Configure OSPF in a Single Area?

OSPF stands for Open Shortest Path First and it represents a routing protocol belonging to the group of link-state routing protocols. OSPF routing protocol is classified among the best dynamic protocols that exist in networks today. It is also considered to…