BGP Overview Sumanta Das Gajendra Mahapatra. Content 1.Introduction 2.Session Establishment 3.Route...
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Transcript of BGP Overview Sumanta Das Gajendra Mahapatra. Content 1.Introduction 2.Session Establishment 3.Route...
Content
1. Introduction
2. Session Establishment
3. Route processing
4. Basic Configuration
5. BGP Police
Introduction to BGP
BGP Characteristics :1. BGP is distance vector protocol with
enhancement - reliable update - Triggered updates only - Rich metrics (called path attributes)Designed to scale to huge internetworks
Basic BGP Configuration
BGP Routing process :Router(config)#router bgp as-number
Configuring External Neighbors :Router(config-router)#neighbor ip-address remote-as as-number
To temporarily disable a BGP neighbor:Router(config-router)#neighbor ip-address shutdown
Configuring BGP Timers:Router(config-router)#timers bgp keepalive holdtime
Per Specific neighbor:Router(config-router)#neighbor [ ip address | peer group name ] timers keepalive holdtime
Basic BGP Configuration
Configuring MD5 Authentication:Router(config-router)#neighbor ip-address password string
Router(config-router)#no auto-summary
Aggregating BGP networksRouter(config-router)#aggregate-address address-prefix mask Router(config-router)#aggregate-address address-prefix mask
summary-only
Basic BGP Configuration
BGP command for monitoring:
Monitorior neighber info:Router>show ip bgp summary
Monitor BGP neighbors on details:Router>show ip bgp neighbor ip-address
Monitor bgp table:Router > show ip bgp
Basic BGP Configuration
Debugging BGP :
Display all tcp transaction :
Router#debug ip tcp transactions
Display significant BGP event
Router#Debug ip bgp events
Debug BGp keepalive packets :
Router#debug ip bgp keepaklives
Display all incoming and outgoing BGp updates :
Router#debug ip bgp updates
BGP Police
BGP Filters :
- As-Path Filters
Configuring BGP AS-Path Filters
Router(Config)#ip as-path access-list number permit | deny regexp
Router(Config-router)#neighbor ip-address filter-list as-path-filter in|out
BGP Police
BGP Filters :
- prefix-Based Filters
Configuration:
router(config-router)#neighbor {ip address| peer-group-name } prefix-list list {in| out}
Router(config-routeer)#distribution-list prefix-list prefix-list out routing-process
BGP Police
Outbound Router Filter ORF format
ORF message consist of the following fields
-AFI/SAFI
-ORF type
-When to refresh
-List of ORF entries
ORF entries depends on the ORF type
ORF capability needs to be negotiated for every supported ORF type