bitmindframes

Configuring a Web Interface:

Switches have web-based config tools that require an onboard HTTP server:
Web browser GUI.
Security Device Manager (SDM).
IP Phone and Telephony apps.
HTTP services ? security hole ? optional authentication.
If many users access HTTP services you may require a separate authentication server.
AAA and TACACS can be used to validate user credentials, (robust).
A less complex method allows use of the enable password.
A local authentication method requires the user to use a login username and password specified in the config.

S1(config)#ip http server ? turns on the server (on by default).
S1(config)#ip http authentication enable.

Read the rest of this entry →

Tags: wan, switch, cisco, router, vtp, study

Key Elements of Ethernet Networks:

CSMA/CD – Only used with half-duplex (hubs).
Full-duplex switches do not use CSMA/CD.
Ethernet signals are sent to every host in the LAN.

Carrier Sense:

All devices must listen before transmitting.
If signal detected (CS), wait before transmitting.
If no tfc detected, can transmit.
While transmitting – must listen for collisions.

Multi-access:

If 2 devices transmit at the same time = collision.

Collision Detection:

Other devices (not involved in collision), and transmitting devices, detect collision.

Read the rest of this entry →

Tags: study, vtp, 802.1q, guides, switch, cisco

LAN Design:

The Hierarchical Network Model:

CCNA focuses on networks for SMBs (small, medium businesses).
A hierarchical design model is recommended.
Easier to manage and expand.
Problems are solved more quickly.

Hierarchical design divides the network into 3 layers.
Core, (CL).
Distribrution, (DL).
Access, (AL).

Each layer provides specific functions.
This “modularity” facilitates scalability and performance.

Access Layer, (AL): lowest

Interfaces with the end device (user).
Includes routers, switches, bridges, hubs and wireless APs.
Provides a means of connecting devices to the network and controlling which one communicate on the network.

Read the rest of this entry →

Tags: vlan, wan, ip, guides, vtp, switch

Bitmindframes Study guides

Spanning Tree Protocol & Layer 2 Redundency.

Layer 2 redundency improves network availability with alternative network paths.
A simple path can be disrupted with little impact.
Redundency is achieved at the distribution & core through additional hardware & alternate paths.
Each Access Layer switch is connected to 2 different Distribution Layer switches.
Each Distribution Layer switch is connected to 2 Core Layer switches.
Spanning Tree Protocol is enabled by default.
Spanning Tree Protocol puts some ports into forwarding & others in blocking.
This prevents Layer 2 switching loops. Spanning Tree Protocol uses a redundant link if the primary fails.

Read the rest of this entry →

Tags: vtp, cisco, switch, router, ip, guides