7. LAN design goals
11-2005
– Functionality--speed and reliability
– Scalability--ability to grow without
Khoa CNTT
major changes
– Adaptability--easily implements new
7/64
technologies
– Manageability--facilitates monitoring
PHẠM VĂN TÍNH
and ease of management
8. LAN design considerations
11-2005
The function and placement of servers
Khoa CNTT
Collision detection issues
Segmentation issues
8/64
Broadcast domain issues
PHẠM VĂN TÍNH
9. Placement of Servers
11-2005
Servers now perform special functions and can be
categorized as either...
– Enterprise Servers--supports all users on the network
Khoa CNTT
DNS , Mail , WEB … servers
should be placed in the main distribution facility (MDF)
or...
9/64
– Workgroup Servers--supports a specific set of users
file serving such as specialized databases
PHẠM VĂN TÍNH
should be place in the intermediate distribution facilities
(IDF) closest to users
10. PHẠM VĂN TÍNH 10/64 Khoa CNTT 11-2005
Placement of Servers
11. LAN Segmentation
11-2005
• Segmentation is the process of splitting a
single collision domain into two or more
collision domains.
Khoa CNTT
• Layer 2 devices such as bridges and
switches reduce the size of a collision
11/64
domain.
• Routers reduce the size of the collision
PHẠM VĂN TÍNH
domain and the size of the broadcast
domain at Layer 3.
12. Basic Steps in LAN design
11-2005
1. Gather requirements and expectations
Khoa CNTT
2. Analyze requirements and data
3. Design the Layer 1, 2, and 3 LAN
structure, or topology
12/64
4. Document the logical and physical
PHẠM VĂN TÍNH
network implementation
13. Gather requirements and expectations
Who are the people who will be using the
11-2005
network?
What is the skill level of these people?
Khoa CNTT
How developed are the organizational
documented policies?
13/64
Has some data been declared mission
critical?
PHẠM VĂN TÍNH
Have some operations been declared
mission critical?
14. Gather requirements and expectations
What protocols are allowed on the network?
11-2005
Are only certain desktop hosts supported?
Who is responsible for LAN addressing, naming,
topology design, and configuration?
Khoa CNTT
What are the organizational human, hardware,
and software resources?
14/64
How are these resources currently linked and
shared?
PHẠM VĂN TÍNH
What financial resources does the organization
have available?
15. PHẠM VĂN TÍNH 15/64 Khoa CNTT 11-2005
Analyze requirements and data
23. PHẠM VĂN TÍNH 23/64 Khoa CNTT 11-2005
VLAN logical map
24. PHẠM VĂN TÍNH 24/64 Khoa CNTT 11-2005
Layer 3 logical map
25. PHẠM VĂN TÍNH 25/64 Khoa CNTT 11-2005
Addressing maps
26. PHẠM VĂN TÍNH 26/64 Khoa CNTT 11-2005
LAYER 1 DESIGN
27. Layer 1 design
11-2005
• Choose cable type.
Khoa CNTT
• Identify work area and HCC.
• Identify MDF, IDF, HCC, VCC and POP.
27/64
• Choose Ethernet or Fast Ethernet.
• Documentation and physical diagrams
PHẠM VĂN TÍNH
28. PHẠM VĂN TÍNH 28/64 Khoa CNTT 11-2005
Example: Wiring closet location
33. MDF and IDF
11-2005
– Whether the LAN is a star or extended star,
the MDF is the center of the star.
• From the workstation to the
Khoa CNTT
telecommunications outlet, the patch cable
should be no more than 3m.
33/64
• From their to the patch panel, called the
HCC, no more than 90m.
PHẠM VĂN TÍNH
• From the patch panel (the HCC) to the
switch, no more than 6m.
34. MDF and IDF
11-2005
– When distances to the MDF are more than
Khoa CNTT
100m, an IDF is normally added.
– The cable run from the IDF to the MDF is
called backbone and is usually fiber.
34/64
– By adding more wiring closets (more IDFs),
you create multiple catchment areas
PHẠM VĂN TÍNH
36. Layer 1 Logical Diagram
Locations and identification of the MDF and IDF
11-2005
wiring closets.
Type and quantity of cabling used to
interconnect the IDFs with the MDF.
Khoa CNTT
Document how many spare cables are available
for increasing the bandwidth between the wiring
closets. For example, if the vertical cabling
36/64
between IDF 1 and the MDF is running at 80%
utilization, two additional pairs could be used to
double the capacity.
PHẠM VĂN TÍNH
Detailed documentation of all cable runs, the
identification numbers, and the port the run is
terminated on at the HCC or VCC.
37. PHẠM VĂN TÍNH 37/64 Khoa CNTT 11-2005
Logical Diagram & Cut Sheets
38. PHẠM VĂN TÍNH 38/64 Khoa CNTT 11-2005
LAYER 2 DESIGN
39. Common Layer 2 Devices
11-2005
Khoa CNTT
39/64
The two most common Layer 2 devices are...
Bridges and
PHẠM VĂN TÍNH
LAN Switches
Microsegmentation of the network reduces the size
of collision domains and reduces collisions.
40. PHẠM VĂN TÍNH 40/64 Khoa CNTT 11-2005
Collisions Domain Size with HUB
41. PHẠM VĂN TÍNH 41/64 Khoa CNTT 11-2005
SWITCH Collision Domain
42. PHẠM VĂN TÍNH 42/64 Khoa CNTT 11-2005
SWITCH with HUB
43. PHẠM VĂN TÍNH 43/64 Khoa CNTT 11-2005
Migrate to Higher Bandwidth
44. Hierarchical design model
11-2005
Core Distribution Access
Layer2/Layer3 switching Layer3 switching Layer2 switching
Khoa CNTT
44/64
PHẠM VĂN TÍNH
45. Switched LANs, access layer overview
11-2005
• Shared bandwidth
Khoa CNTT
• Switched bandwidth
• MAC layer filtering
45/64
• Microsegment
PHẠM VĂN TÍNH
46. Access layer switches
• Catalyst 1900
series
11-2005
Catalyst 1912
• Catalyst 2820
series
Khoa CNTT
• Catalyst 2950
Catalyst 4000
series
46/64
• Catalyst 4000
series
PHẠM VĂN TÍNH
• Catalyst 5000
series
47. Distribution layer overview
11-2005
• Aggregation of the wiring closet
connections
Khoa CNTT
• Broadcast/multicast domain definition
• Virtual LAN (VLAN) routing
47/64
• Any media transitions that need to occur
PHẠM VĂN TÍNH
• Security
48. Distribution layer switches
11-2005
• Catalyst 2926G
Khoa CNTT
• Catalyst 5000
family
48/64
• Catalyst 6000
family
PHẠM VĂN TÍNH
49. Core layer overview
11-2005
• The core layer is a high-speed switching
Khoa CNTT
backbone.
• This layer of the network design should
49/64
not perform any packet manipulation.
PHẠM VĂN TÍNH
50. Core layer switches
Catalyst 8540
11-2005
• Catalyst 6500
series
Khoa CNTT
• Catalyst 8500
series Catalyst 1010
50/64
• IGX 8400 series
PHẠM VĂN TÍNH
• Lightstream 1010
51. PHẠM VĂN TÍNH 51/64 Khoa CNTT 11-2005
LAYER 3 DESIGN
52. Routers and Design
• Routers provide both physical and logical
11-2005
segmentation.
• Logically, routers segment according to Layer 3
addressing dividing the LAN into logical
Khoa CNTT
segments called subnets.
• VLAN capable switches help routers contain
broadcasts.
52/64
• The graphic shows two broadcast domains.
• Notice there is also two subnets. How do we
PHẠM VĂN TÍNH
know that?
• The router provides communication between the
two VLANs.
53. PHẠM VĂN TÍNH 53/64 Khoa CNTT 11-2005
VLANs & Broadcast Domains
54. PHẠM VĂN TÍNH 54/64 Khoa CNTT 11-2005
Diagramming a LAN with Routers
55. Diagramming a LAN with Routers
11-2005
– Notice in the graphic that the two networks
are kept separate by the router.
– Each switch serves a different network
Khoa CNTT
regardless of the physical location of the
devices.
55/64
– To create another physical network in a
structured Layer 1 wiring scheme, simply
PHẠM VĂN TÍNH
patch the HCC and VCC into the correct
switch.
56. Logical & Physical Network Maps
After determining your Layer 1, 2, and 3 design, you
11-2005
can create your addressing (logical) and physical
maps. These are invaluable :
•Give a snapshot of the network
•Show subnet mask info
Khoa CNTT
•Help in troubleshooting
Logical Addressing Mapped to the Physical Network
56/64
PHẠM VĂN TÍNH
57. PHẠM VĂN TÍNH 57/64 Khoa CNTT 11-2005
Physical Network Maps
58. PHẠM VĂN TÍNH 58/64 Khoa CNTT 11-2005
Addressing Maps
60. Cabling
11-2005
C able labels Mounting c able in rac ew ay
Khoa CNTT
P atc h panel S truc ture of a patc h panel
60/64
P unc h T ools P unc hing w ires in J ac k
PHẠM VĂN TÍNH