Switch port configuration

Question 1

Describes the characteristics of Ethernet switching

Answer 1

An Ethernet switch can allocate a dedicated amount of bandwidth to each of its interfaces or ports. The resulting increased network performance occurs
by reducing the number of users connected to an Ethernet segment. In effect, collisions are less probable and the collision domain is reduced in size.

Question 2

Discusses Ethernet scaling

Answer 2

You can scale a Fast Ethernet network by an additional order of magnitude with Gigabit Ethernet (which supports 1000 Mbps or 1 Gbps) using the same IEEE 802.3 Ethernet frame format as before.

Question 3

Covers 10-Gigabit Ethernet

Answer 3

The 10-Gigabit Ethernet, also known as 10GE, and the IEEE 802.3ae standard differ from their predecessors only at the physical layer (PHY); 10GE operates only at full duplex. The standard defines several different transceivers that can be used as Physical Media Dependent (PMD) interfaces.

Question 4

Explains Ethernet autonegotiation

Answer 4

The link speed is determined by electrical signaling so that either end of a link can determine what speed the other end is trying to use. A link’s duplex mode, however, is negotiated through an exchange of information. This means that for one end to successfully autonegotiate the duplex mode, the other end also must be set to autonegotiate.

Question 5

Cada cuantos segundos los CDP adevertisement son envíados por los puertos de un switch.

Answer 5

Cada 60 segundos

Question 6

Explica sobre el protocolo CDP

Answer 6

CDP es un protocolo propiedad de cisco. Los CDP advertisement trabajan sobre la capa 2 ignorando los protocolos de capas superiores. CDP funciona solo un una dirección (no espera respuesta del vecino). Los CDP advertisement no son ruteables a través de la red.

Question 7

Que significan las siglas LLDP

Answer 7

Link layer discovery protocol.

Question 8

Explica sobre el protocolo LLDP

Answer 8

LLDP es un protocolo basado en el estandar 802.1ab, como resultado es un protocolo multivendor. En switches Cisco LLDP está globalmente deshabilitado.

Question 9

Cómo LLDP agrupa la información sobre los dispositivos vecinos?

Answer 9

LLDP utiliza estructuras TLV (Type-length value).

Question 10

Cómo un dispositivo que usa LLDP usa las estructuras TLV?

Answer 10

Un dispositivo mandaría su descripción con un TLV, la IP de gestión en otro TLV, sus requerimientos de power mediante otro TLV. Con esto creando una cadena de TLV interpretados por el dispositivo vecino.

Question 11

Explica sobre PoE

Answer 11

PoE (power over ethernet) es un protocolo con el que se puede energizar equipos finales mediante el cable de red UTP.

Question 12

Menciona 4 métodos PoE que puede usar un switch cisco así como los watts que ofrece cada método.

Answer 12

1 - Cisco inline power | ILP | 7W
2 - IEEE802.3af | PoE | 15.4W
3 - IEEE802.3at | PoE+ | 25.5W
4 - Cisco Universal PoE | UPoE | 60W

Question 13

Explica cuántos PoE power classess existen y el máximo power que ofrecen.

Answer 13

Existen 5 power classess
0 (default) | 15.4 Watt
1 | 4.0 Watt
2 | 7.0 Watt
3 | 15.4 Watt
4 (PoE+) | 30 Watt