Archive for ‘ Switching

DTP Dynamic Trunking Protocol 08 November 2008 at 4:13 pm by admin

Bitmindframes cisco study guides

DTP Dynamic Trunking Protocol

Trunk negotiation is managed by the Dynamic Trunking Protocol (DTP), which is a Cisco proprietary Point-to-Point Protocol.
These various modes are configured using the switchport mode interface command
Switch trunk interfaces support different trunking modes.

  • Access
  • Dynamic desirable (default mode on Catalyst 2950 and 3550)
  • Dynamic auto
  • Trunk
  • Non-negotiate
  • dotq-tunnel (Not an option on the Catalyst 2950.)

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Tags: 802.1q, interface, ip, study, guides, vtp

+ Configuring a catalyst switch By admin 26 August 2008 at 5:32 pm and have Comments Off

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.

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

+ Switching in an Ethernet network By admin 26 August 2008 at 5:22 pm and have Comments Off

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.

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

+ LAN Design & Hierarchical Network Model By admin 15 August 2008 at 12:50 pm and have Comments Off

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.

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

+ STP & Layer 2 Switch redundency By admin 30 June 2008 at 12:17 pm and have Comments Off

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.

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