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.
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.
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.
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.
- VTP is a Layer 2 messaging protocol that was designed to manage the creation and deletion of VLANs and maintain network-wide VLAN database consistency.
What is the Native VLAN?
As you remember from the previous lesson, trunk ports send and receive Ethernet frames tagged with IEEE 802.1q VLAN tags.
- In this lesson, we are going to learn what is Power over Ethernet. What is the difference between the different standards PoE, PoE+, UPOE, and UPOE+? How switches and end devices negotiate PoE settings. How do we configure and verify PoE on Cisco switches and what are the most common use cases?
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.
What is a broadcast domain?
In Ethernet LANs, a broadcast is one-to-all communication, which means that if a node sends a broadcast frame, everybody receives a copy of it.