Distribution Layer Switches

Distribution Layer Switches
As discussed earlier, the primary function of the distribution layer is to provide routing, filtering,
and WAN access and to determine how packets can access the core, if needed.
Distribution layer switches are the aggregation point for multiple access switches and must
be capable of handling large amounts of traffic from these access layer devices. The distribution
layer switches must also be able to participate in MLS and be able to handle a route processor.
The Cisco switches that provide these functions are as follows:
3550 series This range includes a variety of stackable switches supporting a huge range of features.
Full IOS operation complete with MLS is available, and this makes the switch suitable for
both access layer and distribution layer switching.
4000 series One of the most scalable switches, the 4000 can be used as a distribution switch
if the supervisor IV engine supporting MLS is installed. The 4000 series switches support
advanced QoS, security, and flexibility, achieved with a range of modules. Numerous chassis
are available, providing advanced features such as non-blocking architecture and resilience
through redundant supervisors. This range has been given a real boost by Cisco.
6000 The Catalyst 6000 can provide up to 384 10/100Mbps Ethernet connections, 192
100FX FastEthernet connections, or 130 Gigabit Ethernet ports. (With the recent release of the
10/100/1000 card, the 6500 can now support up to 384 10/100/1000 Ethernet connections.) In
addition to regular connections, IP telephone connections with inline power are also supported.
The 6000 can be outfitted with a Multilayer Switch Feature Card (MSFC) to provide router
functionality as well as a Policy Feature Card (PFC) for layer 3 switching functionality.