
Border Gateway Protocol ([BGP](/bgp)) has several built-in [loop](/loops-in-layers-2-and-3) prevention mechanisms that help to safeguard the [routing](/routing) protocol from routing loops.  Some apply to [eBGP](/bgp-definition-of-external-bgp-ebgp) while others to [iBGP](/bgp-definition-of-internal-bgp-ibgp).  The following is a list of features of BGP that help to prevent routing loops:

* [BGP - eBGP loop prevention mechanism same AS number](/bgp-ebgp-loop-prevention-mechanism-same-as-number)
* [BGP - iBGP full-mesh peering](/bgp-ibgp-full-mesh-peering)
* [BGP - iBGP split horizon rule](/bgp-ibgp-split-horizon-rule)
* [BGP Cluster ID](/bgp-cluster-id)
* [BGP Next Hop Address Tracking](/bgp-next-hop-address-tracking)

## Links

https://forum.networklessons.com/t/how-looping-is-avoided-in-bgp-routing/47010/2?u=lagapidis



BGP - Loop Prevention

ASA implicit rule

ASA limit CLI and ASDM access to specific users

ASA packet processing algorithm

ASA prerequisites for high availability

ASA redirect IP SLA messages to log buffer

ASA redundant interface

ASA security levels

ASA syslog logging in multiple context mode

ASA to Firepower migration

ASA troubleshooting IPSec

ASA tunnel-group

ASA understanding version numbers

ASA what triggers an active-standby failover

ASA won't respond to pings from different subnet

Access-List (ACL) Operators

Access-List (ACL)

Anycast Host Addressing

Anycast

Audio and Video over IP Networks

Automation - Ansible connection plugins

BFD - Control Plane Independent (CPI) bit

BFD - intervals and timers

BFD - slow-timers

BFD - with multiple routing protocols

BFD echo mode and operation details

BFD how an administrative change differs from a failure

BFD one-arm echo

BGP - AFI and SAFI

BGP - AS_Path filtering use cases

BGP - Accumulated IGP metric

BGP - Atomic Aggregate Attribute

BGP - Autonomous System (AS)

BGP - Autonomous System Number

BGP - BGP Algorithm within confederations

BGP - Discontiguous Autonomous Systems

BGP - ECMP for specific prefixes

BGP - End-of-RIB marker

BGP - Equal Cost Multipath AS_Path Attribute

BGP - FSM - Active state

BGP - FSM - Connect State

BGP - Finite State Machine (FSM)

BGP - Flowspec

BGP - Graceful Restart Mechanism

BGP - Handling Multiple Communities on a Single Route

BGP - IGP-BGP redistribution best practices

BGP - Labeled Unicast

BGP - Large BGP communities

BGP - Leaking more specific routes

BGP - MED vs AS Prepending

BGP - Multipath Attribute Prerequisites

BGP - Network Layer Reachability Information (NLRI)

BGP - Next Hop Address Tracking vs Route Dampening

BGP - Outbound Route Filtering

BGP - RRs vs confederations

BGP - Synchronization Rule

BGP - TCP Peering Session Process

BGP - The BGP Table

BGP - The BGP table vs the Routing table

BGP - Why is MED non-transitive

BGP - aggregate-address command in action

BGP - aggregate-address default route

BGP - aggregate-address with a single subnet

BGP - bgp redistribute-internal command

BGP - definition of External BGP (eBGP)

BGP - definition of Internal BGP (iBGP)

BGP - eBGP loop prevention mechanism same AS number

BGP - eBGP next hop optimization

BGP - eBGP peerings

BGP - eBGP third party next hop

BGP - iBGP full-mesh peering

BGP - iBGP split horizon rule

BGP - multicast routing

BGP - multihop vs disable-connected-check

BGP - multipath in a DMVPN environment

BGP - multiprotocol BGP

BGP - network command with subnet mask

BGP - network vs redistribute commands

BGP - next-hop-self vs update source

BGP - oldest path attribute

BGP - preventing transit traffic

BGP - redistributing iBGP routes into an IGP

BGP - remove private AS

BGP - route maps and using the continue clause

BGP - routing table entry without exit interface

BGP - transitive and non-transitive attributes

BGP - update-source command

BGP - using peer-groups with multiple outbound policies

BGP - using private ASNs with private IPs

BGP - using public IPs with private ASes

BGP - why is eBGP preferred over iBGP

BGP 4-Byte AS Number - Asdot notation

BGP 4-Byte AS Number - Asdot plus notation

BGP 4-Byte AS Number - Asplain notation

BGP 4-byte ASN Backward Compatibility

BGP AS Override feature

BGP AS number notation

BGP AS_PATH when using aggregate-address

BGP AS_SET and AS_CONFED_SET Deprecated