Category Archives: VLANs

Multi-Protocol Label Switching (MPLS) Explained with Examples

What is Multi-Protocol Label Switching (MPLS)? Multiprotocol Label Switching (MPLS) is a type of network data traffic technique which carries data from one network device to the next using short path labels instead of long and complex network router lookups in a routing table. Ok…simple said; MPLS is best summarized as a middleman protocol between Layer 2 and… Read More »

Cisco Dynamic Trunking Protocol (DTP) Explained

Understanding Dynamic Trunking Protocol (DTP) The Dynamic Trunking Protocol (DTP) is a Cisco proprietary protocol that is automatically enabled on Catalyst 2960 and Catalyst 3560 Series switches. DTP is used to negotiate forming a trunk link between two or more Cisco devices before actually forming the trunk connection. The main benefit of DTP is to increase traffic on a… Read More »

RIP Routing Loop Explained

Split Horizon, Route Poisoning and Holddown Explained Split Horizon RIP as a distance vector protocols is also susceptible to routing loops (network problem which enable a data packet to continually being routed through the same routers over and over. The data packets continue to be routed within the network in an endless circle.) . Split horizon is one… Read More »

DHCP Snooping Explained

WHAT IS DHCP SNOOPING? The Dynamic Host Configuration Protocol (DHCP) allocates IP addresses dynamically, it leases addresses to connected devices and the addresses can be reused when no longer needed. All connected Hosts and end devices that require IP addresses obtained through DHCP must communicate with a DHCP server across the LAN. DHCP snooping acts like a firewall… Read More »

What is Link Layer Discovery Protocol (LLDP)?

Understanding LLDP and LLDP-MED The smooth running operation of the various networking devices in a LAN or switched network means that all protocols and applications are enabled and that all devices and are configured correctly. However, the larger the network gets, the more difficult it will be for the network administrator to control, manage and sort out configuration problems. This… Read More »

What is Syslog? Syslog Explained.

System Message Logging – SYSLOG Modern network devices have advanced from simple transmitting of messages (email.documents, multimedia etc), network devices like Cisco routers and switches provide the features for network administrators to reading system messages from their internal buffer about network situation at a particular time. The way do this is by using Syslog server. Cisco network devices (Routers… Read More »

How to Cable LANs and WANs

Cabling LANs and WANs. When planning the installation of LAN cabling, choosing the cables necessary to make a successful LAN or WAN connection requires consideration of the different media types. There are many different Physical layer implementations that support multiple media types: • UTP (Category 5, 5e, 6, and 7) • Fiber-optics • Wireless Each media type has… Read More »

PPP: What is CHAP? Explained with Examples

Challenge Handshake Authentication Protocol (CHAP) Challenge Handshake Authentication Protocol (CHAP) is more secure than PAP. It involves a three-way exchange of a shared secret. During link establishment, CHAP conducts periodic challenges to make sure that the remote host still has a valid password value. While PAP basically stops working once authentication is established, this leaves the network vulnerable to… Read More »

What is GLBP? Explained with Examples

Understanding Gateway Load Balancing Protocol (GLBP) Gateway Load Balancing Protocol (GLBP) is a Cisco proprietary solution for redundancy and load balancing in an IP network. GLBP allow automatic selection and simultaneous recovery from first hop router failures. GLBP provides load balancing over multiple (router) gateways using a single virtual IP address and multiple virtual MAC addresses.  Each host… Read More »

How Switches Forward Frames Explained

Switch Packet Forwarding Methods. A switch uses a different method of forwarding frames in Ethernet network. These methods are Store-and-Forward or Cut-through Switching. Store-and-Forward Switching In store-and-forward switching, when the switch receives the frame, it stores the received data in buffers until the complete frame has been received. While in the storage process, the switch checks and analyses… Read More »