Function
As with hubs, Ethernet implementations of network switches are the most common.
Mainstream Ethernet network switches support either 10/100 Mbit/s or 10/100/1000
Mbit/s ports Ethernet standards. Large switches may have 10 Gbit/s ports.
The network switch, packet switch (or just switch) plays an integral part in most
Ethernet local area networks or LANs. Mid-to-large sized LANs contain a number of
linked managed switches. Small Office, Home Office (SOHO) applications typically
use a single switch, or an all-purpose converged device such as gateway access to
small office/home office broadband services such as DSL router or cable, WiFi
Router. In most of these cases, the end user device contains a router and
components that interface to the particular physical broadband technology, as in the
Linksys 8-port and 48-port devices. User devices may also include a telephone
interface to VoIP.
Role of switches in networks
Network switch is a marketing term rather than a technical one. Switches may
operate at one or more OSI layers, including physical, data link, network, or
transport (i.e., end-to-end). A device that operates simultaneously at more than one
of these layers is called a multilayer switch, although use of the term is diminishing.
In switches intended for commercial use, built-in or modular interfaces make it
possible to connect different types of networks, for example Ethernet, Fiber Channel,
ATM, and 802.11. This connectivity can be at any of the layers mentioned. While
Layer 2 functionality is adequate for speed-shifting within one technology,
interconnecting technologies such as Ethernet and token ring are easier at Layer 3.
Again, "switch" is principally a marketing term; interconnection of different Layer 3
networks is done by routers. If there are any features that characterize "Layer-3
switches" as opposed to general-purpose routers, it tends to be that they are
optimized, in larger switches, for high-density Ethernet connectivity.
In some service provider and other environments where there is a need for much
analysis of network performance and security, switches may be connected between
WAN routers as places for analytic modules. Some vendors provide firewall,
network
intrusion detection, and performance analysis modules that can plug into switch
ports. Some of these functions may be on combined modules
In other cases, the switch is used to create a "mirror" image of data that can go to
an external device. Since most switch port mirroring provides only one mirrored
stream, Ethernet hubs can be useful for fanning out data to several read-only
analyzers. This is especially popular when using open-source network analysis tools
running over Linux, such as the Snort intrusion detection system and the Wire shark
(formerly ethereal) protocol analyzer.
Layer-specific functionality
(2 paginas)
(216 paginas)
(72 paginas)
(60 paginas)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Comentarios a estos manuales