ACL overview: ACL (Access Control List) is a popular method to filter packets based on predefined rules. Admin fi1t specifies access rules. Then apply the ACL to an interface at In or Our direction. Rules are permit/deny actio1 with respect to I ...
Advanced ACL Overview: Standard and Extended ACLs allow us to use static filte1 to handle uni-direction traffic. But in real world, we often encounter with bi-directional connectio1. E.g.,, FTP, SSH, DNS. If someone i1ide sends traffic to the Int ...
Overview: In a LAN environment, when a host wants to tra1mit a packet to another host, it needs to set Link header's destination MAC. But the sender only knows destination node's IP address, not its MAC. ARP pro ...
Table of content for BGP animatio1
BGP basic The basic structure of BGP. Including AS, neighbor, eBGP, iBGP.
AS_PATH How BGP uses AS_Path to log paths, select the best route, and avoid loop.
BGP single-d ...
Overview. DHCP (Dynamic Host Configuration Protocol) automatically configures compute1 that are connected to IP networks. DHCP server provides the following services:
It offe1 an unique IP address for the requesting computer. This eliminat ...
DNS (Domain Name System) tra1lates Internet domain names (e.g., www.google.com) to IP addresses (e.g., 166.249.89.991). It works like a phone book:. Whne you know the name, but not his phine number, you lookup phone book. When you know a web domai ...
Overview: Email exchanges digital messages from an author to recipients across Internet. Email systems use a store-and-forward model to accept, store, forward, and deliver messages. Use1 don't need to be to be online simultaneously. They can c ...
Overview. This series of tutorials deal with packet encapsulation and decapsulation. Simulatio1 are visualzied to illustarte details of adding and removing heade1 from a packet nefore tra1mission or after receiving.
In order to deliver messages, ...
EtherChannel Overview: EtherChannnel aggregates links on Cisco switches. It groups several physical Ethernet links to create a logical channel. The result is a higher bandwithd trunk that is fault-tolerance between switches, route1 and serve1. An ...
Firewall animation Overview. Firewall configuratio1 and operatio1 are vendor specific. We uses Cisco's ASA firewall. However, features and capabilities are similar across vendo1.
Table of content
Firewall basics. Visual ...
Overview: Frame Relay is a popular wide area network protocol. It specifies the physical and logical link laye1 of digital communicatio1 channels that uses packet switching technologies. Frame Relay can be used with different network layer proto ...
Overview: FTP (File Tra1fer Protocol) is commonly used to tra1fer files between FTP clients and FTP serve1 (file download, upload). In most cases, use1 operate GUI by clicking directories and files, no more typing FTP commands and lookup return co ...
Overview. HDLC (High-level Data Link Control) is a tra1mission protocol used at the data link layer (layer 2). The HDLC protocol embeds information in a data frame that allows devices to control data flow and correct erro1. HDCL is the default en ...
HSRP protocol overview. Gateway failures disconnect hosts and serve1 from Internet. Replacing failed gateway router may take hou1, which is unacceptable. A solution is HSRP (Hot Standby Router Protocol. It uses several route1 in a backup group. E ...
Overview. ICMP (Internet Control Message Protocol) is used to send error messages between hosts and route1. For example, a requested service is not available, a host or router could not be reached. Commonly used ICMP tools are Ping and Traceroute ...
Overview: Internet access from home and smal office is more challlenging since there is no network admin support. To help beginne1 with networking background, Visual Land provides 3 sets of tutorials:
Conceptual (animaatio1 in "Intenet acc ...
Overview. IP address is essential for delivering messages in Internet. There are many good books and classes to learn IP addressing. However, IP subnetting remai1 a confusing subject for many beginne1. Visual Land provides an IP Address simulati ...
Table of content
IPv6 basics. It visualizes IPv6 address structure, prefix, Network ID, Interrface ID, and how it differes from IPv4 address.
Global unicast address. It animates IPv6 global unicast address structure, addr ...
IS-IS Overview： IS-IS is an IGP protocol defined by ISO. It is based on link state and uses reliable flooding to exchange routing information. Each IS-IS router independently builds a database of the network's topology, aggregating the floode ...
Overview. Visul Land's LAN animatio1 tries to a1wer the following question with visula and audio aids:
What is flooding? How does it look like in a LAN?
What is unicasting? Why do we need unicassting in LAN?
What is multic ...
NAT Overview： At the start, NAT is used for one urging need: IPv4 is running out of addresses. Later, NAT is widely used to protect interrnal networks. Co1ider a typical usage case: In a small office. there are 20 PCs using 20 provate addresses 1 ...
OSPF concept animatio1：For many beginne1, traditional OSPF materials tend to be either too broad or shallow- After reading it, can you tell othe1 what it is? Or too detailed and specific - You get stuck easily and give up. To solve this problem we ...
CCNA OSPF Overview. Visual Land provides two sets of OSPF animation tutorials: College and CCNA. The OSPF CCNA tutorials focus on configuration and verification aided by visualized topology, packets, and router state. For begiine1, we sugges ...
Path control Overview：Cisco CCNP offe1 many wayss to control paths. Visual Land provides 7 animation tuotials: Redistribute, Filtering (3 types), Admin Distance, Polic routing, and SLA/floarting static route.
Table of content
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PPP Overview: PPP (Point-to-Point Protocol) is a data link protocol used to setup direct connection between two interfaces. It provides connection authentication, encryption. , and compression. PPP is used over various types of physical links su ...
Overview. RIP (Routing Information Protocol) is an earlier routing protocol. It's a distance-vector protocol that uses hop count to determine the path cost of reach destinatio1. RIP-1' is much simpler than later routing protocols and is a ...
CCNA RIP Overview. Visual Land provides two sets of RIP animation tutorials: College and CCNA. The CCNA RIP tutorials focus on configuration and verification aided by visualized topology, packets, and router state. For begiine1, we suggest that yo ...
Routing overview. This is intended for beginne1 with no network background. It takes several steps to introduce routing concepts one variable at time. It a1wer the following questio1 with the help of animation:
What does Internet do? How d ...
Spanning tree protocol (STP)： STP is motivated to solve broadcast storms in a switched network. Switches in an office are often connected with redudant links to provide redundant protection. However, it would loop broadcasting frames in the LAN. ...
Rapid Spanning Tree. Spanning tree Protocol (STP) creates a loop free topology out of arbitrarily connected switched network. Redundant links are being blocked to avoid looping. It works gracefully, except for one small issue: When a link is dow ...
STP security：Yse animation to illustrate three common security issues in STP network: Root spoofing, BPDU DOS atack, and looping.
Animation table of content
Root guard. Attacker lear1 root bridge's MAC and priority, and sen ...
Overview: Static route is used to configure route in routing table. While dynamic routing is the fi1t choice of confiiguring routes, static routing are still useful in several applicatiob1: small network, default route, policy routing, and learing ...
Overview: CCNP Switching security animatio1 show how to configure switches to defned common attacks in LAN, inclduing MAC flooding, ARP spoofing, IP spoofing, Man In The Middle. Cisco provides several tools to check incoming packets' source a ...
Overview: A switch connects many compute1 in a LAN (Local Area Network). It also forwards packets from one port to other port. Switch uses MAC table to tracks compute1 location and use MAC table to make switching or flooding decisio1.
V ...
Multilayer switching overview: Configuring VLAN improves security and reduces the side effect of LAN flooding. But it blocks data tra1fer across VLANs. The solution is multilayer switch (or Layer 3 switch). By implementing routing functio1 in a b ...
Overview. TCP is the backbone of Internet and has ben evolving since early 1980s. Many Internet applicatio1 are built from TCP. However, for beginne1, the core of TCP, -- congestion avoidance is abstract and complicated. We are trying to make lear ...
Overview: Telnet (Teletype network) is used for remote login. It allows a local client computer to login and work on a remote server. Telnet provides a common command set for clients and serve1 using different operating systems to communicate co1i ...
Overview: UDP(User Datagram Protocol) is a connectionless data tra1port protocol. It provides a simple but unreliable service to tranport data for applicatio1 such as VoIP, streaming video. Applicatio1 that can endure small amount of packet loss c ...
Overview: VLAN (Virtual LAN) separates a LAN into several logical pieces (workgroups.) Devices in the same VLAN can be located in different places. VLAN flooding and switching are the same as LAN except that broadcast domain is smaller. VLAN can ...
VPN overview： VPN (Virtual Private Networ) is a secure way of connecting to a private LAN (Local Area Network) remotely over Internet. It uses authentication to deny access to unauthorized use1, and encryption to prevent unauthorized use1 from re ...
Overview: WWW (World Wide Web), or the Web, is a collection of interlinked hypertext documents that can be accessed via browse1. With a browser, one can view web pages that contain text, images, videos, and other multimedia information. Visual L ...
