Connecting Switches
Switch deployment in a arrangement involves two steps: concrete connectivity and switch
configuration. This area describes the admission and cabling requirements for accessories in a
switch block. Cable admission charge be fabricated to the animate anchorage of a about-face in adjustment to make
initial configurations. Concrete connectivity amid switches and end users involves cabling
for the assorted types of LAN ports.
Console Anchorage Cables/Connectors
A terminal appetite affairs on a PC is usually appropriate to interface with the animate anchorage on
a switch. Assorted types of animate cables and animate connectors are associated with anniversary Cisco
switch family.
All Catalyst about-face families use an RJ-45-to-RJ-45 rollover cable to accomplish the console
connection amid a PC (or terminal or modem) and the animate port. A rollover cable is made
so that pin 1 on one RJ-45 adapter goes to pin 8 on the added RJ-45 connector, pin 2 goes to
pin 7, and so forth. In added words, the cable charcoal collapsed while the two RJ-45 connectors point
in adverse directions.
To affix the PC end, the rollover cable plugs into an RJ-45 to DB-9 or DB-25 “Terminal”
adapter (or a DB-25 “Modem” adapter for a modem connection). At the about-face end, the rollover
cable plugs anon into the RJ-45 jack of the animate port. This bearings is accurate for the Catalyst
1900, 2820, 2900, 3500, 2926G, 2948G, 4912G, 5000 Supervisor IIG/III/IIIG, and the 6000
switches.
On the Catalyst 4003, 5000 Supervisor I/II, and the 8500 switches, the rollover cable must
connect to an RJ-45 to DB-25 “Modem” adapter. These switches acquire a DB-25 animate port
connector that is a changeable DCE.
Once the animate anchorage is cabled to the PC, terminal, or modem, a terminal appetite program
can be started or a user affiliation can be made. The animate ports on all about-face families require
an asynchronous consecutive affiliation at 9600 baud, 8 abstracts bits, no parity, 1 stop bit, and no flow
control.
Ethernet Anchorage Cables/Connectors
Catalyst switches abutment a array of arrangement connections, including all forms of Ethernet. In
addition, Catalyst switches abutment several types of cabling, including UTP and optical fiber.
On Catalyst 1900 and 2820 alternation switches, the Ethernet ports are fixed-speed with 12 or 24
10BaseT and one or two 100BaseTX or 100BaseFX ports. The 10BaseT ports can be connected
only to added 10BaseT-capable accessories (including 10/100 autosensing devices), and the
100BaseX to added 100BaseX-capable devices. The 10BaseT and 100BaseTX ports use
Category 5 UTP cabling and RJ-45 connectors.
78 Chapter 3: Basic About-face and Anchorage Configuration
The 100BaseFX ports use two-strand multimedia cilia (MMF) with SC connectors to provide
connectivity. The SC connectors on the cilia cables are aboveboard in shape. These connectors snap
in and out of the about-face anchorage adapter as the adapter is pushed in or pulled out. One fiber
strand is acclimated as a address aisle and the added as a acquire path. Therefore, the address cilia on
one about-face accessory should affix to the acquire cilia on the added end.
The butt of the Catalyst about-face families abutment 10/100 autosensing (using Fast Ethernet
autonegotiation) and Gigabit Ethernet. Switched 10/100 ports use RJ-45 connectors on
Category 5 UTP cabling to complete the connections. These ports can be affiliated to other
10BaseT, 100BaseTX, or 10/100 autosensing devices. UTP cabling is abiding so that RJ-45
pins 1,2 and 3,6 anatomy two askance pairs. These pairs are affiliated beeline through to the far
end.
In adjustment to affix two 10/100 about-face ports back-to-back, as in an admission band to distribution
layer link, a Category 5 UTP crossover cable charge be used. In this case, RJ-45 pins 1,2 and 3,6
are still askance pairs, but 1,2 on one end affix to 3,6 on the added end, and 3,6 on one end
connect to 1,2 on the added end.
NOTE Because UTP Ethernet admission use alone pairs 1,2 and 3,6, some cable bulb installers only
connect these pairs and leave the actual two brace positions empty. While this move provides
Ethernet connectivity, it is not acceptable convenance for approaching needs. Instead, all four pairs of the RJ-
45 adapter should be affiliated end-to-end. For example, a abounding four-pair UTP cable bulb can
be acclimated for either Ethernet or Token Ring connectivity, after rewiring. (Token Ring UTP
connections use pairs 3,6 and 4,5.) Also, to be accordant with the new IEEE 802.3ab standard
for Gigabit Ethernet over copper, all four pairs charge be acclimated end-to-end.
Gigabit Ethernet Anchorage Cables/Connectors
Gigabit Ethernet admission booty a altered access by accouterment modular connectivity
options. Catalyst switches with Gigabit Ethernet ports acquire affiliated ellipsoidal openings
that acquire Gigabit Interface Converters (GBICs). GBIC modules accommodate the media personality
for the anchorage so that assorted types of cables can be connected. In this way, the about-face anatomy is
completely modular and requires no above change to acquire a new media type. Instead, the
appropriate GBIC bore is hot-swappable and is acquainted into the about-face to abutment the new
media. GBICs are accessible for the afterward Gigabit Ethernet media:
• 1000BaseSX GBIC—short amicableness connectivity application SC cilia connectors and MMF
for distances up to 550 meters (1804 feet).
• 1000BaseLX/LH GBIC—long wavelength/long booty connectivity application SC fiber
connectors and either MMF or single-mode cilia (SMF); MMF can be acclimated for distances
up to 550 meters (1804 feet) and SMF can be acclimated for distances up to 10 km (32,810 feet).
Connecting Switches 79
• 1000BaseZX GBIC—extended ambit connectivity application SC cilia connectors and
SMF; can be acclimated for distances up to 70 km and alike to 100 km back acclimated with premium
grade SMF.
• GigaStack GBIC—uses a proprietary adapter with a high-data-rate chestnut cable with
enhanced arresting candor and electromagnetic arrest (EMI) performance; provides
a GBIC-to-GBIC affiliation amid stacking Catalyst switches or amid any two
Gigabit about-face ports over a abbreviate distance.
CAUTION The fiber-based GBICs consistently acquire the acquire cilia on the larboard SC adapter and the transmit
fiber on the appropriate SC connector. These GBICs could aftermath airy laser radiation from the
transmit SC connector. Therefore, consistently accumulate bare SC connectors covered with the rubber
plugs and do not attending anon into the SC connectors.
Figure 3-2 illustrates a fiber-based GBIC bore and how one is installed in a Gigabit Ethernet
switch port.
Figure 3-2 Gigabit Interface Converter
Token Ring Anchorage Cables/Connectors
Catalyst switches abutment UTP Token Ring connections. These ports accomplish at either 4 or 16
Mbps, in several bisected and full-duplex modes. RJ-45 connectors on Category 5 UTP cabling use
twisted pairs 3,6 and 4,5. These pairs are affiliated beeline through to the far end.