Static ARP Entries

Static ARP entry is a permanent IP-to-MAC binding in the ARP table (ARP cache). One reason that you may want to do this is if two nodes in the LAN are constantly communicating and never change their IP and MAC addresses.

ARP vulnerabilities

Address Resolution Protocol (ARP) has been designed in times when network security has not been very developed. Therefore the protocol is clear text with no embedded security.

ARP Role

Address Resolution Protocol (ARP) is a very fundamental protocol in computer networking.  When a PC wants to send a message over the network, it has to encapsulate the data down the layers of the OSI model.

Configuring VTP

Verifying the topology

Before you start configuring VLAN Trunking Protocol on Cisco switches, it is very important to first verify that all inter-switch links are trunks.

This lesson discusses the Native VLAN - one of the most confusing and challenging topics in the CCNA exam — and networking overall. Although it may seem simple at first, it often causes misunderstandings and mistakes in real-world setups.

All LAN switching examples up until now were with simple LAN topologies. In the real world, every network topology uses redundant devices and links because availability is paramount for computer networks. Let's look at how switches behave when there are redundant links.

As we learned in the previous lesson, the first step in switches' operational logic is to receive an Ethernet frame from the transmitting node.