HUB Generalidades
HUB
Generalidades
HUB
Son dispositivos de capa1
Sólo regeneran la señal
Y la envían mediante broadcast a todos los puertos
HUB
Es un dispositivo de Networking
Networking significa interconexión de estaciones de trabajo, periféricos, terminales y otros dispositivos
HUB
Características
HUB
Llamado también ConcentradorRepresenta el centro de red en
topología estrellaSiendo el Puerto la interfaz de un
dispositivo de red:Es un Repetidor Multipuerto
HUB
Funciones
HUB
Amplifica las señalesLas propaga por la redNo filtraNo determina o conmuta rutasSe lo utiliza como punto de
concentración de la red
HUB
Una Clasificación
HUB
ActivosRepiten señales enviadas a través de
ellos
PasivosNo repiten, sino que meramente dividen
las señales enviadas a través de ellos.
HUB
Otra Clasificación
HUB
InteligentesTienen puertos de consolaSe pueden programar para
administrar el tráfico de la red
No inteligentesSin capacidad de realizar ninguna
administración
HUB
Aplicaciones
Aplicacoines
Con el propósito de aumentar el número de puertos, pueden conectarse
en cascada (hubs autónomos)
en pila (hubs conectables en pila)
Autónomos o en pila?
AutónomosPequeños grupos de trabajo4 ó 5 puertos
En pilaPermiten expansión modular
HUBS CISCO
Algunos modelos
Cisco 1538 Series — Micro Hubs 10/100
Table 13-4: Physical and Environmental Specifications for Cisco 1538 Series
Description Specification
Dimensions (H xW x D)
3.1 x 11.2 x 8.7 in. (7.85 x 28.4 x 22.1 cm); heightincludes stacking curves on top of switch
Weight 3.0 lb (1.4 kg)
Operatingtemperature
32 to 104°F (0 to 40°C)
Operatinghumidity
10 to 85% noncondensing
Operatingaltitude
up to 9840 ft (3000 m)
Storagetemperature
-40 to 149°F (-25 to 65°C)
Storage altitude 30,000 ft (9146 m)
Stack Cisco Micro Hubs to Create Larger Managed Networks
Connect Up to Eight Workstations to the Cisco Micro Hub
Modos de configuración
Existen dos:
guest mode
administrator mode (also called privileged mode). The commands available in guest mode are a subset of those available in administrator mode.
Pasaje entre modos
Qué comando escribimos:
Hub> Hub> enable
Password: ******
Hub#
Comandos de Configuración
Syntax: show hub information [hub id]
Hub> show hub informationHub ID Type H/W ver F/W ver SNMP-Agent-----------------------------------------1 1503 1.0 1.01 Yes2 1502 1.0 1.01 No3 1503 1.0 1.01 No
Command Display Definitions Hub ID--Number used to identify the hub in a stack. An
integer between 1 and 5. Read the section "Hub IDNumbers" earlier in this chapter for information abouthow to determine hub ID numbers.
Type--Model number of the hub: 1502 or 1503.
H/W ver--Hub's hardware version.
F/W ver--Hub's firmware version.
Agent--Whether or not the hub contains an active SNMP agent.
Comandos estadísticos
Syntax: show system statistics Hub> show system statisticsFrames : 9755Bytes : 78040Collisions : 671Alignment errors : 45CRC errors : 33Total errors : 867
Command Display Definitions Frames--Number of frames (packets) passing through the
hub.
Bytes--Number of bytes passing through the hub.
Collisions--Number of times that network devices attached to any one of the hubs inthe stack have attempted to send data simultaneously.
Alignment errors--Number of mis-synchronized data packets.
CRC errors--Number of cyclic redundancy check (CRC) errors.
Total errors--Total number of errors of the following types: frame control sequence,alignment, frames-too-long, short events, late events, jabber, and data rate mismatches
Syntax: show hub statistics [hub id] Hub> show hub statistics 1 Alignment CRC TotalHub ID Frames Bytes Collisions Errors Errors Errors--------------------------------------------------------------1 1039 29354 264 23 12 486
Command Display Definitions Hub ID--Position of the hub in the stack, from top to
bottom.
Frames--Number of frames (packets) passing through the hub.
Bytes--Number of bytes passing through the hub.
Collisions--Number of times that network devices attached to any one of the hubs inthe stack have attempted to send data simultaneously.
Alignment errors--Number of mis-synchronized data packets.
CRC errors--Number of CRC errors.
Total errors--Total number of errors, including the following types: frame control sequence,alignment, frames-too-long, short events, late events, jabber, and data rate mismatches.