Standard Access Lists – CCNA Course

standard access lists ccna course

Standard IP access lists filter network traffic by examining the source IP address in a packet. You create a standard IP access list by using the access-list numbers 19 or 13001999 (expanded range). Access list types are generally differentiated using a number. Based on the numbers used when the access list is created, the router … Read more

Introduction to Access Lists

Introduction to Access Lists

An Access list is essentially a list of conditions that categorize packets. They can really help when you need to exercise control over network traffic. An access list would be your tool of choice for decision making in these situations. One of the most common and easiest to understand uses of access lists is filtering … Read more

Configuring voice VLANs – CCNA Course

Configuring voice VLANs

The voice VLAN feature enables access ports to carry IP voice traffic from an IP phone. When a switch is connected to a Cisco IP phone, the IP phone sends voice traffic with Layer 3 precedence and Layer 2 class of service (CoS) values, which are both set to 5 for voice traffic; all other … Read more

Configuring Inter-VLAN Routing

configuring inter vlan routing

By default, only hosts that are members of the same VLAN can communicate. To change this and allow inter-VLAN communication, you need a router or a layer 3 switch. I’m going to start with the router approach. To support ISL or 802.1Q routing on a Fast Ethernet interface, the router’s interface is divided into logical … Read more

Configuring Virtual Local Area Networks (VLANs)

Configuring Virtual Local Area Networks (VLANs)

It may come as surprise to you, but configuring VLANs is actually pretty easy. Figuring out which users you want in each VLAN is not; it’s extremely time-consuming. But once you’ve decided on the number of VLANs you want to create and established which users you want to belong to each one, it’ time to … Read more

VLAN Identification Methods – CCNA Course

vlan identification methods

Most of the time, VLANs are created by a sys admin who proceeds to assign switch ports to each VLAN. VLANs of this type are known as static VLANs. If you don’t mind doing a little more work when you begin this process, assign all the host devices hardware addresses into a database so your … Read more

Introduction to Virtual Local Area Network (VLAN)

introduction to virtual area network vlan

The following figure shows how layer 2 switched networks are typically designed as flat networks. With this configuration, every broadcast packet transmitted is seen by every device on the network regardless of whether the device needs to receive that data or not. By default, routers allow broadcasts to occur only within the originating network, while … Read more

Enhancements to Spanning Tree Protocol (STP)

enhancements to stp

The 802.1d spanning tree protocol was created with very few design flaws; however, as with most great things, there is always room for improvement. The biggest grievance the networking community had with spanning tree protocol was the slow convergence when a topology change occurred in the network. Recall that it could take up to 30 … Read more

Initial Switch Configurations – CCNA Course

initial switch configurations

Catalyst switches, for the most part, are designed so that the default state of the switch allows for basic layer 2 functionality without requiring any configuration from the administrator. For example, the physical interfaces on the switch are already enabled, which means that you can plug a cable in the switch and the interface operates … Read more

Layer 2 Switching and Spanning Tree Protocol (STP)

layer 2 switching and stp

We already have an article “Datalink networking concepts”, that you can use bridges and switches to segment a LAN into smaller collision domains. This article looks in close detail at the operations of bridges and switches. Specifically, you will investigate the transparent functionality that occurs when a switch is building and utilizing its frame forwarding … Read more

EIGRP Configuration – CCNA Course

eigrp configurations

One of the greatest aspects of EIGRP is that you get all this advanced functionality with minimal configuration effort. EIGRP essentially follows the same configuration guidelines as RIPv2. Namely, it must advertise directly connected networks. Because EIGRP is also classful by default, the networks configured must be at a default classful boundary. A key element … Read more

Balanced Hybrid operations – CCNA Course

balanced hybrid operations eigrp

Balanced hybrid routing protocols are sometimes called advanced distance vector routing protocols. The rationale behind this logic is that these routing protocols use similar metrics and have a maximum hop count as distance vector routing protocols. However, balanced hybrid routing protocols discover neighbors and put them in a neighbor table before exchanging routing information, as … Read more