Day-29: VLAN Trunking.

The trunk port basically used to connect between switches. It carries traffic on one or more VLANs on the same physical links. Trunk ports are called tagged ports. Can have two or more VLANs configured. Can carry multiple VLAN information. By default, all the VLAN traffic is allowed from a trunk port. The trunk is basically carrying the… Read More »

Day-28: VLAN (Virtual local area networks)

VLANs define broadcast domains in a Layer 2 network. A broadcast domain is the set of all devices that will receive broadcast frames originating from any device within the set. Broadcast domains are typically bounded by routers because routers do not forward broadcast frames. Layer 2 switches create broadcast domains based on the configuration of the switch. Switches… Read More »

Day-27:LLDP(Link Layer Discovery Protocol )

LLDP is an Open standard protocol, equivalent to CDP Defined in IEEE 802.1ab Media Endpoint Discovery (MED) is an LLDP enhancement for Voice over IP (VoIP) applications. Limited to only 802.1 media types (i.e. Ethernet…but not WAN interfaces) CDP and LLDP can be operational on the same interface. LLDP uses attributes that contain type, length, and value descriptions(TLV… Read More »

Day-26: Cisco Discovery Protocol.

CDP is a Cisco discovery protocol and it is a Cisco proprietary protocol. CDP is a Layer 2 protocol for neighbor discovery. CDP Provides information on the platform, interface, IP address, and OS version. CDP runs on the data-link layer and is enabled by default. CDP helps to prepare the map of the network diagram . Enabling CDP.… Read More »

Day-25: Introduction to Switching.

The switch is a multiport bridge, It means both bridge and switches divide the collision and broadcast domain, and both work on Layer 2 of the OSI model. Layer 2 Switch is a form of Ethernet switch that switches packets by looking at their physical addresses (MAC addresses). These switches operate at the data-link layer 2 of the… Read More »

Day-24 : Configuring Telnet.

Historically, Telnet provided access to a command-line interface on a remote host. However, because of serious security concerns when using Telnet over an open network such as the Internet, its use for this purpose has waned significantly in favor of SSH. Telnet is basically used for accessing the network device remotely for management purposes. because it’s not possible… Read More »

Day-22: Basic and Initial Configuration Commands in Cisco Routers & Switches.

As we have already discussed that CISCO device has a command hierarchy and it has multiple modes in CLI. The basic CLI modes that we will be referring to below are as follows: Router> =User EXEC ModeRouter# = Privileged EXEC modeRouter(config)#= Global Configuration ModeRouter(config-if)# =Interface Configuration ModeRouter(config-line)# =Line Configuration Mode How to configure the Hostname? How To Configure… Read More »

Day-21: Cisco IOS Command Structure.

IOS has a command hierarchy Router> – User EXEC mode Router# – Privileged EXEC mode Router(config)# – Configuration mode (notice the # sign indicates this is accessible only at privileged EXEC mode) Router(config-if)# – Interface level within configuration mode Router(config-router)# – Routing engine level within configuration mode Router(config-line)# – Line level (vty, tty, async) within configuration mode User… Read More »

Day-23: Securing Cisco Devices By Configuring Passwords.

In this blog, we will discuss, How we can configure the password in our cisco devices for preventing unauthorized access. IOS has a command hierarchy Router> – User (or EXEC) mode Router# – Privileged EXEC (or Enable) mode Configuration modes Router(config)#  – Global Configuration Mode. Router(config-if)# – Interface Configuration Mode. Router(config-router)#     – Router Configuration Mode. Once you will… Read More »