CCNP-SWITCHING 250-111
Mohamed Samir YouTube channel
Double CCIEs #27042(R/S&SP)
Mohamed Samir
© 2011 Internetwork
All rights reserved. Cell: +20 10 09517999 Email : eng.mohammedsn@gmail.com
CCNP-SWITCHING 250-111
Course Overview
Mohamed Samir
© 2011 Internetwork
All rights reserved. Cell: +20 10 09517999 Email : eng.mohammedsn@gmail.com
Switching overview
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23 chapter
Part I Designing Campus Networks
Part II Building a Campus Network
Part III Working with Redundant Links
Part IV Multilayer Switching
Part V Monitoring Campus Networks
Part VI Implementing High Availability
Part VII Securing Switched Networks
Mohamed Samir
© 2011 Internetwork
All rights reserved. Cell: +20 10 09517999 Email : eng.mohammedsn@gmail.com
Part I: Designing
Campus Networks
Mohamed Samir
© 2011 Internetwork
All rights reserved. Cell: +20 10 09517999 Email : eng.mohammedsn@gmail.com
Designing Campus Networks
• Predictable Network Model should offer low
maintenance and high availability.
• You should scale the network to easily support
future expansions and upgrades
• efficiently connecting users with the resources
they need, regardless of location
• Cisco has refined a hierarchical approach to
network design to be efficient, intelligent,
scalable, and easily managed.
Mohamed Samir
© 2011 Internetwork
All rights reserved. Cell: +20 10 09517999 Email : eng.mohammedsn@gmail.com
Hierarchical Design
• Access Layer:
• exists where the end users are connected to the network.
Access switches usually provide Layer 2 (VLAN) connectivity
between users
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Low cost per switch port
High port density
Scalable uplinks to higher layers
High availability
Ability to converge network services (that is, data, voice,
video)
• Security features and quality of service (QoS)
Mohamed Samir
© 2011 Internetwork
All rights reserved. Cell: +20 10 09517999 Email : eng.mohammedsn@gmail.com
Hierarchical Design
• Distribution Layer:
• provides interconnection between the campus
network’s access and core layers.
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Aggregation of multiple access layer switches
High Layer 3 routing throughput for packet handling
Security and policy-based connectivity functions
QoS features
Scalable and redundant high-speed links to the core
and access layers
Mohamed Samir
© 2011 Internetwork
All rights reserved. Cell: +20 10 09517999 Email : eng.mohammedsn@gmail.com
Hierarchical Design
• Core Layer:
• provides connectivity between all distribution
layer devices. The core, sometimes referred to as
the backbone
• Very high Layer 3 routing throughput
• No costly or unnecessary packet manipulations
(access lists, packet filtering)
• Redundancy and resilience for high availability
• Advanced QoS functions
Mohamed Samir
© 2011 Internetwork
All rights reserved. Cell: +20 10 09517999 Email : eng.mohammedsn@gmail.com
Hierarchical Design
• You can divide enterprise campus networks
into the following
• Switch block: A group of access layer switches,
together with their distribution switches
Usually, no more than 2000 users should be
placed within a single switch block.
Core : The campus network’s backbone, which
connects all switch blocks.
Mohamed Samir
© 2011 Internetwork
All rights reserved. Cell: +20 10 09517999 Email : eng.mohammedsn@gmail.com
Hierarchical Design
• Switch Block Redundancy
• two independent power supplies.
• implement most of the components in
redundant pairs
• The two distribution switches can use one of
several redundant gateway protocols to
provide an active IP gateway
• Best Practice Loop-Free Switch Block Topology
Mohamed Samir
© 2011 Internetwork
All rights reserved. Cell: +20 10 09517999 Email : eng.mohammedsn@gmail.com
Hierarchical Design
• Network Core
• connect two or more switch blocks in a campus
network
• foundation and carries much more traffic than any
other switch block.
• Preferably, the links between distribution and core layer
switches should be Layer 3 routed interfaces
• Redundant links connect each switch block’s
distribution layer portion to each of the dual core
switches
Mohamed Samir
© 2011 Internetwork
All rights reserved. Cell: +20 10 09517999 Email : eng.mohammedsn@gmail.com
Hierarchical Design
• Collapsed Core
• Should all networks have a distinct redundant
core layer?
• A collapsed core block is one in which the
hierarchy’s core layer is collapsed into the
distribution layer
• Cisco Products in a Hierarchical Network Design
Mohamed Samir
© 2011 Internetwork
All rights reserved. Cell: +20 10 09517999 Email : eng.mohammedsn@gmail.com
Any questions ?
Mohamed Samir
© 2011 Internetwork
All rights reserved. Cell: +20 10 09517999 Email : eng.mohammedsn@gmail.com
Thank you
for your
time ! 
‫شكرا‬
Mohamed Samir
© 2011 Internetwork
All rights reserved. Cell: +20 10 09517999 Email : eng.mohammedsn@gmail.com