Course Content
Packet Forwarding
0/2
Network Device Communication
Forwarding Architectures
Spanning Tree
An overview of how switches become aware of other switches and prevent loops.
0/2
Spanning Tree Protocol Fundamentals
Rapid Spanning Tree Protocol
Advanced Spanning Tree Tuning
0/2
Spanning Tree Topology Tuning
Additional Spanning Tree Protection Mechanisms
Multiple Spanning Tree Protocol (MST)
0/1
Multiple Spanning Tree Protocol
VLAN Trunks and EtherChannel Bundles
0/3
VLAN Trunking Protocol (VTP)
Dynamic Trunking Protocol (DTP)
EtherChannel Bundle
IP Routing Essentails
0/4
Routing Protocol Overview
Path Selection
Static Routing
Virtual routing and forwarding (VRF)
EIGRP
0/4
EIGRP Fundamentals
EIGRP Path Metric Calculation
EIGRP Failure Detection and Timers
EIGRP Route Summarization
OSPF
0/4
OSPF Fundamentals
OSPF Configuration
OSPF Default Route Advertisement
Common OSPF Optimizations
Advanced OSPF
The (OSPF) protocol scales well with proper network planning. IP addressing schemes, area segmentation, address summarization, and hardware capabilities for each area should considered when designing a network.
0/6
OSPF Areas
OSPF Link-State Announcements
Discontiguous Networks
OSPF Path Selection
OSPF Routes Summarization
OSPF Route Filtering
OSPFv3
0/3
OSPFv3 Fundamentals
OSPFv3 Configurations
IPv4 Support in OSPFv3
BGP
0/4
BGP Fundamentals
Basic BGP Configuration
BGP Route Summarization
Multiprotocol BGP for IPv6
Advanced BGP
0/6
BGP Multihoming
BGP Conditional Matching
BGP Route Maps
BGP Route Filtering and Manipulation
BGP Communities
BGP Path Selection
Multicast
0/5
Multicast Fundamentals
Multicast Addressing
Internet Group Management Protocol
Protocol Independent Multicast
Rendezvous Points
QoS
0/5
The Need for QoS
QoS Models
Classification and Marking
Policing and Shaping
Congestion Management and Avoidance
IP Services
0/3
Time Synchronization
First Hop Redundancy Protocol
Network Address Translation
Overlay Tunnels
0/4
Generic Routing Encapsulation (GRE) Tunnels
IPsec Fundamentals
Cisco Location/ID Separation Protocol (LISP)
Virtual Extensible Local Area Network (VXLAN)
Wireless Signals & Modulation
0/2
Understanding Basic Wireless Theory
Carrying Data over a Wireless Signal
Wireless Infrastructure
0/3
WLAN Topologies
Leveraging Antennas for Wireless Coverage
Pairing Lightweight APs and WLCs
Understanding Wireless Roam and Location Services
0/3
Roaming Overview
Roaming Between Centralized Controllers
Locating Devices in a Wireless Network
Authenticating Wireless Clients
0/4
Open Authentication
Authenticating with Pre-Shared Key (PSK)
Authenticating with EAP
Authenticating with WebAuth
Troubleshooting Wireless Connectivity
0/2
Troubleshooting Client Connectivity from WLC
Troubleshooting Connectivity Problems at the AP
Enterprise Network Architecture
0/2
Hierarchical LAN Design Model
Enterprise Network Architecture Options
Fabric Technologies
0/2
Software-Defined Access (SD-Access)
Software Defined WAN (SD-WAN)
Network Assurance
0/6
Network Diagnostic Tools
Debugging
NetFlow and Flexible NetFlow
Switched Port Analyzer (SPAN) Technologies
IP SLA
DNA Center Assurance
Secure Network Access Control
0/3
Network Security Design for Threat Defense
Network Access Control (NAC)
Next-Generation Endpoint Security
Network Device Access Control and Infrastructure Security
0/5
Access Control Lists (ACLs)
Terminal Lines and Password Protection
Authentication, Authorization, and Accounting (AAA)
Zone-Based Firewall (ZBFW)
Control Plane Policing (CoPP)
Virtualization
0/2
Server Virtualization
Network Functions Virtualization
Foundational Network Programmability Concepts
0/6
CLI
Application Programming Interface (API)
Data Models and Supporting Protocols
DevNet
GitHub
Basic Python Components and Scripts
Introduction to Automation Tools  
To provide a high-level overview of some of the most common configuration management and automation tools that are available.
0/3
Embedded Event Manager (EEM)
Agent-Based Automation Tools
Agentless Automation Tools
ENCOR Course
About Lesson

BGP Route Summarization

how route summarization works with BGP and some of the design considerations with summarization.

Summarizing prefixes conserves router resources and accelerates best-path calculation by reducing the size of the table. Summarization also provides the benefit of stability by hiding route flaps from downstream routers, thereby reducing routing churn.

Summarizing Prefixes

There are two techniques for BGP summarization:

  • Static – Create a static route to Null0 for the summary network prefix and then advertise the prefix with a network statement. The downfall of this technique is that the summary route is always advertised, even if the networks are not available.
  • Dynamic – Configure an aggregation network prefix. When viable component routes that match the aggregate network prefix enter the BGP table, then the aggregate prefix is created. The originating router sets the next hop to Null0 as a discard route for the aggregated prefix for loop prevention.

Aggregate Address

Dynamic route summarization is accomplished with the BGP address family configuration command aggregate-address network subnet-mask [summary–only] [as–set].   Example 11-15 Configuring BGP Route Aggregation

Atomic Aggregate

Aggregated routes act like new BGP routes with a shorter prefix length. When a BGP router summarizes a route, it does not advertise the AS_Path information from before the aggregation. BGP path attributes like AS_Path, MED, and BGP communities are not included in the new BGP advertisement.

Atomic Aggregate

  Example 11-23 Examining the BGP Attribute for the Atomic Aggregate Attribute

Route Aggregation with AS_SET

To keep the BGP path information history, the optional as-set keyword may be used with the aggregate-address command. As the router generates the aggregate route, BGP attributes from the component aggregate routes are copied over to it.   Example 11-24 Configuring Aggregation While Preserving BGP Attributes   Other useful information:

 

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