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Table Of Contents
BGP Features Roadmap
First Published: May 2, 2005Last Updated: March 28, 2011This feature roadmap lists the Cisco IOS features documented in the Cisco IOS IP Routing: BGP Configuration Guide and maps them to the documents in which they appear. The roadmap is organized so that you can select your release train and see the features in that release. Find the feature name you are searching for and click on the URL in the "Where Documented" column to access the document containing that feature.
Feature and Release Support
Table 1 lists BGP feature support for the following Cisco IOS software release trains:
•
Cisco IOS Releases 12.2T, 12.3, 12.3T, 12.4 and 12.4T
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note
Table 1 lists the most recent release of each software train first and the features in alphabetical order within the release.
Table 1 Supported BGP Features
12.0(32)S12
BGP Support for 4-Byte ASN
The BGP Support for 4-Byte ASN feature introduced support for 4-byte autonomous system numbers. Because of increased demand for autonomous system numbers, in January 2009 the IANA will start to allocate 4-byte autonomous system numbers in the range from 65536 to 4294967295.
12.0(31)S
BGP Route-Map Continue Support for an Outbound Policy
The BGP Route-Map Continue Support for an Outbound Policy feature introduces support for continue clauses to be applied to outbound route maps.
12.0(31)S
BGP Support for BFD
Bidirectional Forwarding Detection (BFD) is a detection protocol designed to provide fast forwarding path failure detection times for all media types, encapsulations, topologies, and routing protocols. In addition to fast forwarding path failure detection, BFD provides a consistent failure detection method for network administrators. Because the network administrator can use BFD to detect forwarding path failures at a uniform rate, rather than the variable rates for different routing protocol hello mechanisms, network profiling and planning will be easier, and reconvergence time will be consistent and predictable. The main benefit of implementing BFD for BGP is a significantly faster reconvergence time.
12.0(29)S
BGP Support for Fast Peering Session Deactivation
The BGP Support for Fast Peering Session Deactivation feature introduced an event driven notification system that allows a Border Gateway Protocol (BGP) process to monitor BGP peering sessions on a per-neighbor basis. This feature improves the response time of BGP to adjacency changes by allowing BGP to detect an adjacency change and deactivate the terminated session in between standard BGP scanning intervals. Enabling this feature improves overall BGP convergence.
12.0(29)S
BGP Support for IP Prefix Import from Global Table into a VRF Table
The BGP Support for IP Prefix Import from Global Table into a VRF Table feature introduces the capability to import IPv4 unicast prefixes from the global routing table into a Virtual Private Network (VPN) routing/forwarding (VRF) instance table using an import route map.
BGP Support for IP Prefix Import from Global Table into a VRF Table
12.0(29)S
BGP Support for Next-Hop Address Tracking
The BGP Support for Next-Hop Address Tracking feature is enabled by default when a supporting Cisco IOS software image is installed. BGP next-hop address tracking is event driven. BGP prefixes are automatically tracked as peering sessions are established. Next-hop changes are rapidly reported to the BGP routing process as they are updated in the RIB. This optimization improves overall BGP convergence by reducing the response time to next-hop changes for routes installed in the RIB. When a bestpath calculation is run in between BGP scanner cycles, only next-hop changes are tracked and processed.
12.0(27)S
BGP Cost Community Support for EIGRP MPLS VPN PE-CE
The BGP Cost Community Support for EIGRP MPLS VPN PE-CE feature provides BGP cost community support for mixed EIGRP MPLS VPN network topologies that contain back door routes.
12.0(27)S
BGP Support for Dual AS Configuration for Network AS Migrations
The BGP Support for Dual AS Configuration for Network AS Migrations feature extends the functionality of the BGP Local-AS feature by providing additional autonomous-system path customization configuration options. The configuration of this feature is transparent to customer peering sessions, allowing the provider to merge two autonomous-systems without interrupting customer peering arrangements. Customer peering sessions can later be updated during a maintenance window or during other scheduled downtime.
12.0(27)S
BGP Support for TTL Security Check
The BGP Support for TTL Security Check feature introduced a lightweight security mechanism to protect external Border Gateway Protocol (eBGP) peering sessions from CPU utilization-based attacks using forged IP packets. Enabling this feature prevents attempts to hijack the eBGP peering session by a host on a network segment that is not part of either BGP network or by a host on a network segment that is not between the eBGP peers.
12.0(26)S
BGP MIB Support Enhancements
The BGP MIB Support Enhancements feature introduced support in the CISCO-BGP4-MIB for new SNMP notifications.
12.0(26)S
Regex Engine Performance Enhancement
The Regex Engine Performance Enhancement feature introduces a new regular expression engine that is designed to process complex regular expressions. This new regular expression engine does not replace the existing engine. The existing engine is preferred for simple regular expressions and is the default engine and in Cisco IOS software. Either engine can be selected from the command-line interface (CLI).
12.0(24)S
BGP Configuration Using Peer Templates
The BGP Configuration Using Peer Templates feature introduces a new mechanism that groups distinct neighbor configurations for Border Gateway Protocol (BGP) neighbors that share policies. Configuration templates provide an alternative to peer group configuration and overcome some of the limitations of peer groups.
12.0(24)S
BGP Cost Community
The BGP Cost Community feature introduces the cost extended community attribute. The cost community is a non-transitive extended community attribute that is passed to internal BGP (iBGP) and confederation peers but not to external BGP (eBGP) peers. The cost community feature allows you to customize the local route preference and influence the best path selection process by assigning cost values to specific routes.
12.0(24)S
BGP Dynamic Update Peer Groups
The BGP Dynamic Update Peer Groups feature introduces a new algorithm that dynamically calculates and optimizes update groups of neighbors that share the same outbound policies and can share the same update messages. In previous versions of Cisco IOS software, BGP update messages were grouped based on peer group configurations. This method of grouping updates limited outbound policies and specific-session configurations. The BGP Dynamic Update Peer Group feature separates update group replication from peer group configuration, which improves convergence time and flexibility of neighbor configuration.
12.0(24)S
BGP Link Bandwidth
The Border Gateway Protocol (BGP) Link Bandwidth feature is used to advertise the bandwidth of an autonomous system exit link as an extended community. This feature is configured for links between directly connected external BGP (eBGP) neighbors. The link bandwidth extended community attribute is propagated to iBGP peers when extended community exchange is enabled. This feature is used with BGP multipath features to configure load balancing over links with unequal bandwidth.
12.0(24)S
BGP Multipath Load Sharing for eBGP and iBGP in an MPLs VPN
The BGP Multipath Load Sharing for eBGP and iBGP feature allows you to configure multipath load balancing with both external BGP (eBGP) and internal BGP (iBGP) paths in Border Gateway Protocol (BGP) networks that are configured to use Multiprotocol Label Switching (MPLS) Virtual Private Networks (VPNs). This feature provides improved load balancing deployment and service offering capabilities and is useful for multi-homed autonomous systems and Provider Edge (PE) routers that import both eBGP and iBGP paths from multihomed and stub networks.
12.0(24)S
BGP Route-Map Continue
The BGP Route-Map Continue feature introduces the continue clause to BGP route map configuration. The continue clause allows for more programmable policy configuration and route filtering and introduces the capability to execute additional entries in a route map after an entry is executed with successful match and set clauses. Continue clauses allow the network operator to configure and organize more modular policy definitions so that specific policy configurations need not be repeated within the same route map.
12.0(22)S
BGP Conditional Route Injection
The BGP Conditional Route Injection feature allows you to inject more specific prefixes into a BGP routing table over less specific prefixes that were selected through normal route aggregation. These more specific prefixes can be used to provide a finer granularity of traffic engineering or administrative control than is possible with aggregated routes.
12.0(22)S
BGP Hybrid CLI
The BGP Hybrid CLI feature simplifies the migration of BGP networks and existing configurations from the network layer reachability information (NLRI) format to the address family identifier (AFI) format. This new functionality allows the network operator to configure commands in the AFI format and save these command configurations to existing NLRI formatted configurations. The feature provides the network operator with the capability to take advantage of new features and provides support for migration from the NLRI format to the AFI format.
12.0(22)S
BGP Increased Support of Numbered AS-Path Access Lists to 500
The BGP Increased Support of Numbered AS-Path Access Lists to 500 feature increases the maximum number of autonomous systems access lists that can be configured using the ip as-path access-list command from 199 to 500.
12.0(22)S
BGP Next Hop Unchanged
The BGP Next Hop Unchanged feature allows BGP to send an update to an eBGP multihop peer with the next hop attribute unchanged.
12.0(22)S
BGP Outbound Route Map to Set IP Next Hop
The BGP Outbound Route Map to Set IP Next Hop feature allows a route reflector to modify the next hop attribute for a reflected route.
12.0(22)S
BGP Policy Accounting Output Interface Accounting
Border Gateway Protocol (BGP) policy accounting (PA) measures and classifies IP traffic that is sent to, or received from, different peers. Policy accounting was previously available on an input interface only. The BGP Policy Accounting Output Interface Accounting feature introduces several extensions to enable BGP PA on an output interface and to include accounting based on a source address for both input and output traffic on an interface. Counters based on parameters such as community list, autonomous system number, or autonomous system path are assigned to identify the IP traffic.
12.0(22)S
BGP Prefix-Based Outbound Route Filtering
The BGP Prefix-Based Outbound Route Filtering feature uses BGP outbound route filtering (ORF) send and receive capabilities to minimize the number of BGP updates that are sent between BGP peers. Configuring this feature can help reduce the number of system resources required for generating and processing routing updates by filtering out unwanted routing updates at the source. For example, this feature can be used to reduce the amount of processing required on a router that is not accepting full routes from a service provider network.
12.0(22)S
BGP Restart Session After Max-Prefix Limit
The BGP Restart Session After Max-Prefix Limit feature enhances the capabilities of the neighbor maximum-prefix command with the introduction of the restart keyword. This enhancement allows the network operator to configure the time interval at which a peering session is reestablished by a router when the number of prefixes that have been received from a peer has exceeded the maximum prefix limit.
12.0(22)S
BGP Route-Map Policy List Support
The BGP Route-Map Policy List Support feature introduces new functionality to BGP route maps. This feature adds the capability for a network operator to group route map match clauses into named lists called policy lists. A policy list functions like a macro. When a policy list is referenced in a route map, all of the match clauses are evaluated and processed as if they had been configured directly in the route map. This enhancement simplifies the configuration of BGP routing policy in medium-size and large networks because a network operator can preconfigure policy lists with groups of match clauses and then reference these policy lists within different route maps. The network operator no longer needs to manually reconfigure each recurring group of match clauses that occur in multiple route map entries.
12.0(21)S
BGP 4 MIB Support for per-Peer Received Routes
BGP 4 MIB Support for per-Peer Received Routes introduces a new table in the CISCO-BGP4-MIB that provides the capability to query (by using Simple Network Management Protocol [SNMP] commands) for routes that are learned from individual Border Gateway Protocol (BGP) peers.
12.0(9)S
BGP Policy Accounting
Border Gateway Protocol (BGP) policy accounting measures and classifies IP traffic that is sent to, or received from, different peers. Policy accounting is enabled on an input interface, and counters based on parameters such as community list, autonomous system number, or autonomous system path are assigned to identify the IP traffic.
12.2(25)S
BGP Cost Community Support for EIGRP MPLS VPN PE-CE
The BGP Cost Community Support for EIGRP MPLS VPN PE-CE feature provides BGP cost community support for mixed EIGRP MPLS VPN network topologies that contain back door routes.
12.2(25)S
BGP MIB Support Enhancements
The BGP MIB Support Enhancements feature introduced support in the CISCO-BGP4-MIB for new SNMP notifications.
12.2(25)S
BGP Support for Dual AS Configuration for Network AS Migrations
The BGP Support for Dual AS Configuration for Network AS Migrations feature extends the functionality of the BGP Local-AS feature by providing additional autonomous-system path customization configuration options. The configuration of this feature is transparent to customer peering sessions, allowing the provider to merge two autonomous-systems without interrupting customer peering arrangements. Customer peering sessions can later be updated during a maintenance window or during other scheduled downtime.
12.2(25)S
BGP Support for IP Prefix Import from Global Table into a VRF Table
The BGP Support for IP Prefix Import from Global Table into a VRF Table feature introduces the capability to import IPv4 unicast prefixes from the global routing table into a Virtual Private Network (VPN) routing/forwarding (VRF) instance table using an import route map.
BGP Support for IP Prefix Import from Global Table into a VRF Table
12.2(25)S
BGP Support for Named Extended Community Lists
The BGP Support for Named Extended Community Lists feature introduces the ability to configure extended community lists using names in addition to the existing numbered format.
12.2(25)S
BGP Support for Sequenced Entries in Extended Community Lists
The BGP Support for Sequenced Entries in Extended Community Lists feature introduces automatic sequencing of individual entries in BGP extended community lists. This feature also introduces the ability to remove or resequence extended community list entries without deleting the entire existing extended community list.
12.2(25)S
BGP Support for TTL Security Check
The BGP Support for TTL Security Check feature introduced a lightweight security mechanism to protect external Border Gateway Protocol (eBGP) peering sessions from CPU utilization-based attacks using forged IP packets. Enabling this feature prevents attempts to hijack the eBGP peering session by a host on a network segment that is not part of either BGP network or by a host on a network segment that is not between the eBGP peers.
12.2(25)S
Loadsharing IP Packets Over More Than Six Parallel Paths
The Loadsharing IP Packets Over More Than Six Parallel Paths feature increases the maximum number of parallel routes that can be installed to the routing table for multipath loadsharing.
12.2(25)S
Suppress BGP Advertisement for Inactive Routes
The Suppress BGP Advertisements for Inactive Routes feature allows you to configure the suppression of advertisements for routes that are not installed in the Routing Information Base (RIB). Configuring this feature allows Border Gateway Protocol (BGP) updates to be more consistent with data used for traffic forwarding.
12.2(22)S
BGP Policy Accounting Output Interface Accounting
Border Gateway Protocol (BGP) policy accounting (PA) measures and classifies IP traffic that is sent to, or received from, different peers. Policy accounting was previously available on an input interface only. The BGP Policy Accounting Output Interface Accounting feature introduces several extensions to enable BGP PA on an output interface and to include accounting based on a source address for both input and output traffic on an interface. Counters based on parameters such as community list, autonomous system number, or autonomous system path are assigned to identify the IP traffic.
12.2(22)S
Regex Engine Performance Enhancement
The Regex Engine Performance Enhancement feature introduces a new regular expression engine that is designed to process complex regular expressions. This new regular expression engine does not replace the existing engine. The existing engine is preferred for simple regular expressions and is the default engine and in Cisco IOS software. Either engine can be selected from the command-line interface (CLI).
12.2(18)S
BGP Configuration Using Peer Templates
The BGP Configuration Using Peer Templates feature introduces a new mechanism that groups distinct neighbor configurations for BGP neighbors that share policies. Configuration templates provide an alternative to peer group configuration and overcome some of the limitations of peer groups.
12.2(18)S
BGP Cost Community
The BGP Cost Community feature introduces the cost extended community attribute. The cost community is a non-transitive extended community attribute that is passed to internal BGP (iBGP) and confederation peers but not to external BGP (eBGP) peers. The cost community feature allows you to customize the local route preference and influence the best path selection process by assigning cost values to specific routes.
12.2(18)S
BGP Dynamic Update Peer Groups
The BGP Dynamic Update Peer Groups feature introduces a new algorithm that dynamically calculates and optimizes update groups of neighbors that share outbound policies and can share update messages. In previous versions of Cisco IOS software, BGP update messages were grouped based on peer-group configurations. This method of grouping updates limited outbound policies and specific-session configurations. The BGP Dynamic Update Peer Groups feature separates update group replication from peer group configuration, which improves convergence time and flexibility of neighbor configuration.
12.2(18)S
BGP Increased Support of Numbered AS-Path Access Lists to 500
The BGP Increased Support of Numbered AS-Path Access Lists to 500 feature increases the maximum number of autonomous systems access lists that can be configured using the ip as-path access-list command from 199 to 500.
12.2(18)S
BGP Restart Session After Max-Prefix Limit
The BGP Restart Session After Max-Prefix Limit feature enhances the capabilities of the neighbor maximum-prefix command with the introduction of the restart keyword. This enhancement allows the network operator to configure the time interval at which a peering session is reestablished by a router when the number of prefixes that have been received from a peer has exceeded the maximum prefix limit.
12.2(18)S
BGP Route-Map Continue
The BGP Route-Map Continue feature introduces the continue clause to BGP route map configuration. The continue clause allows for more programmable policy configuration and route filtering and introduces the capability to execute additional entries in a route map after an entry is executed with successful match and set clauses. Continue clauses allow the network operator to configure and organize more modular policy definitions so that specific policy configurations need not be repeated within the same route map.
Continue clauses are supported in outbound route maps only in Cisco IOS Release 12.0(31)S and later releases.
12.2(18)S
BGP Route-Map Policy List Support
The BGP Route-Map Policy List Support feature introduces new functionality to BGP route maps. This feature adds the capability for a network operator to group route map match clauses into named lists called policy lists. A policy list functions like a macro. When a policy list is referenced in a route map, all of the match clauses are evaluated and processed as if they had been configured directly in the route map. This enhancement simplifies the configuration of BGP routing policy in medium-size and large networks because a network operator can preconfigure policy lists with groups of match clauses and then reference these policy lists within different route maps. The network operator no longer needs to manually reconfigure each recurring group of match clauses that occur in multiple route map entries.
12.2(14)S
BGP 4 MIB Support for per-Peer Received Routes
BGP 4 MIB Support for per-Peer Received Routes introduces a new table in the CISCO-BGP4-MIB that provides the capability to query (by using Simple Network Management Protocol [SNMP] commands) for routes that are learned from individual Border Gateway Protocol (BGP) peers.
12.2(14)S
BGP Conditional Route Injection
The BGP Conditional Route Injection feature allows you to inject more specific prefixes into a BGP routing table over less specific prefixes that were selected through normal route aggregation. These more specific prefixes can be used to provide a finer granularity of traffic engineering or administrative control than is possible with aggregated routes.
12.2(14)S
BGP Link Bandwidth
The Border Gateway Protocol (BGP) Link Bandwidth feature is used to advertise the bandwidth of an autonomous system exit link as an extended community. This feature is configured for links between directly connected external BGP (eBGP) neighbors. The link bandwidth extended community attribute is propagated to iBGP peers when extended community exchange is enabled. This feature is used with BGP multipath features to configure load balancing over links with unequal bandwidth.
12.2(14)S
BGP Multipath Load Sharing for eBGP and iBGP in an MPLs VPN
The BGP Multipath Load Sharing for eBGP and iBGP feature allows you to configure multipath load balancing with both external BGP (eBGP) and internal BGP (iBGP) paths in Border Gateway Protocol (BGP) networks that are configured to use Multiprotocol Label Switching (MPLS) Virtual Private Networks (VPNs). This feature provides improved load balancing deployment and service offering capabilities and is useful for multi-homed autonomous systems and Provider Edge (PE) routers that import both eBGP and iBGP paths from multihomed and stub networks.
12.2(14)S
BGP Named Community Lists
The BGP Named Community Lists feature introduces a new type of community list called the named community list. The BGP Named Community Lists feature allows the network operator to assign meaningful names to community lists and increases the number of community lists that can be configured. A named community list can be configured with regular expressions and with numbered community lists. All rules of numbered communities apply to named community lists except that there is no limitation on the number of community attributes that can be configured for a named community list.
12.2(14)S
BGP Next Hop Unchanged
The BGP Next Hop Unchanged feature allows BGP to send an update to an eBGP multihop peer with the next hop attribute unchanged.
12.2(14)S
BGP Outbound Route Map to Set IP Next Hop
The BGP Outbound Route Map to Set IP Next Hop feature allows a route reflector to modify the next hop attribute for a reflected route.
12.2(14)S
BGP Prefix-Based Outbound Route Filtering
The BGP Prefix-Based Outbound Route Filtering feature uses BGP ORF send and receive capabilities to minimize the number of BGP updates that are sent between BGP peers. Configuring this feature can help reduce the number of system resources required for generating and processing routing updates by filtering out unwanted routing updates at the source. For example, this feature can be used to reduce the amount of processing required on a router that is not accepting full routes from a service provider network.
12.2(14)S
iBGP Multipath Load Sharing
The iBGP Multipath Load Sharing feature enables the BGP speaking router to select multiple iBGP paths as the best paths to a destination. The best paths or multipaths are then installed in the IP routing table of the router.
12.2(33)SB
BGP Graceful Restart per Neighbor
The BGP Graceful Restart per Neighbor feature enables or disables the BGP graceful restart capability for an individual BGP neighbor, including using peer session templates and BGP peer groups.
12.2(33)SB
BGP Neighbor Policy
The BGP Neighbor Policy feature introduces new keywords to two existing commands to display information about local and inherited policies. When BGP neighbors use multiple levels of peer templates, it can be difficult to determine which policies are applied to the neighbor. Inherited policies are policies that the neighbor inherits from a peer-group or a peer-policy template.
12.2(33)SB
BGP Route-Map Continue Support for an Outbound Policy
The BGP Route-Map Continue Support for an Outbound Policy feature introduces support for continue clauses to be applied to outbound route maps.
12.2(33)SB
BGP Support for BFD
Bidirectional Forwarding Detection (BFD) is a detection protocol designed to provide fast forwarding path failure detection times for all media types, encapsulations, topologies, and routing protocols. In addition to fast forwarding path failure detection, BFD provides a consistent failure detection method for network administrators. Because the network administrator can use BFD to detect forwarding path failures at a uniform rate, rather than the variable rates for different routing protocol hello mechanisms, network profiling and planning will be easier, and reconvergence time will be consistent and predictable. The main benefit of implementing BFD for BGP is a significantly faster reconvergence time.
12.2(31)SB2
Per-VRF Assignment of BGP Router ID
The Per-VRF Assignment of BGP Router ID feature introduces the ability to have VRF-to-VRF peering in Border Gateway Protocol (BGP) on the same router. BGP is designed to refuse a session with itself because of the router ID check. The per-VRF assignment feature allows a separate router ID per VRF using a new keyword in the existing bgp router-id command. The router ID can be manually configured for each VRF or can be assigned automatically either globally under address family configuration mode or for each VRF.
12.2(31)SB
BGP Support for Fast Peering Session Deactivation
The BGP Support for Fast Peering Session Deactivation feature introduced an event driven notification system that allows a Border Gateway Protocol (BGP) process to monitor BGP peering sessions on a per-neighbor basis. This feature improves the response time of BGP to adjacency changes by allowing BGP to detect an adjacency change and deactivate the terminated session in between standard BGP scanning intervals. Enabling this feature improves overall BGP convergence.
12.2(31)SB
BGP Selective Address Tracking
The BGP Selective Address Tracking feature introduced the use of a route map for next-hop route filtering and fast session deactivation. Selective next-hop filtering uses a route map to selectively define routes to help resolve the BGP next hop, or a route map can be used to determine if a peering session with a BGP neighbor should be reset when a route to the BGP peer changes.
Configuring Advanced BGP Features
12.2(31)SB
BGP Support for TCP Path MTU Discovery per Session
Border Gateway Protocol (BGP) support for Transmission Control Protocol (TCP) path maximum transmission unit (MTU) discovery introduced the ability for BGP to automatically discover the best TCP path MTU for each BGP session. The TCP path MTU is enabled by default for all BGP neighbor sessions, but you can disable, and subsequently enable, the TCP path MTU globally for all BGP sessions or for an individual BGP neighbor session.
12.2(28)SB
BGP 4 MIB Support for per-Peer Received Routes
BGP 4 MIB Support for per-Peer Received Routes introduces a new table in the CISCO-BGP4-MIB that provides the capability to query (by using Simple Network Management Protocol [SNMP] commands) for routes that are learned from individual Border Gateway Protocol (BGP) peers.
12.2(28)SB
BGP Support for Nonstop Routing (NSR) with Stateful Switchover (SSO)
The BGP Support for Nonstop Routing (NSR) with Stateful Switchover (SSO) feature enables provider edge (PE) routers to maintain Border Gateway Protocol (BGP) state with customer edge (CE) routers and ensure continuous packet forwarding during a Route Processor (RP) switchover or during a planned In-Service Software Upgrade (ISSU) for a PE router. CE routers do not need to be Nonstop Forwarding (NSF)-capable or NSF-aware to benefit from BGP NSR capabilities on PE routers. Only PE routers need to be upgraded to support BGP NSR—no CE router upgrades are required. BGP NSR with SSO, thus, enables service providers to provide the benefits NSF with the additional benefits of NSR without requiring CE routers to be upgraded to support BGP graceful restart.
BGP Support for Nonstop Routing (NSR) with Stateful Switchover (SSO)
12.2(27)SBC
BGP Configuration Using Peer Templates
The BGP Configuration Using Peer Templates feature introduces a new mechanism that groups distinct neighbor configurations for BGP neighbors that share policies. Configuration templates provide an alternative to peer group configuration and overcome some of the limitations of peer groups.
12.2(27)SBC
BGP Cost Community
The BGP Cost Community feature introduces the cost extended community attribute. The cost community is a non-transitive extended community attribute that is passed to internal BGP (iBGP) and confederation peers but not to external BGP (eBGP) peers. The cost community feature allows you to customize the local route preference and influence the best path selection process by assigning cost values to specific routes.
12.2(27)SBC
BGP Dynamic Update Peer Groups
The BGP Dynamic Update Peer Groups feature introduces a new algorithm that dynamically calculates and optimizes update groups of neighbors that share outbound policies and can share update messages. In previous versions of Cisco IOS software, BGP update messages were grouped based on peer group configurations. This method of grouping updates limited outbound policies and specific-session configurations. The BGP Dynamic Update Peer Groups feature separates update group replication from peer group configuration, which improves convergence time and flexibility of neighbor configuration.
12.2(27)SBC
BGP Increased Support of Numbered AS-Path Access Lists to 500
The BGP Increased Support of Numbered AS-Path Access Lists to 500 feature increases the maximum number of autonomous systems access lists that can be configured using the ip as-path access-list command from 199 to 500.
12.2(27)SBC
BGP Route-Map Continue
The BGP Route-Map Continue feature introduces the continue clause to BGP route map configuration. The continue clause allows for more programmable policy configuration and route filtering and introduces the capability to execute additional entries in a route map after an entry is executed with successful match and set clauses. Continue clauses allow the network operator to configure and organize more modular policy definitions so that specific policy configurations need not be repeated within the same route map.
Continue clauses are supported in outbound route maps only in Cisco IOS Release 12.0(31)S and later releases.
12.2(27)SBC
BGP Route-Map Policy List Support
The BGP Route-Map Policy List Support feature introduces new functionality to BGP route maps. This feature adds the capability for a network operator to group route map match clauses into named lists called policy lists. A policy list functions like a macro. When a policy list is referenced in a route map, all of the match clauses are evaluated and processed as if they had been configured directly in the route map. This enhancement simplifies the configuration of BGP routing policy in medium-size and large networks because a network operator can preconfigure policy lists with groups of match clauses and then reference these policy lists within different route maps. The network operator no longer needs to manually reconfigure each recurring group of match clauses that occur in multiple route map entries.
12.2(27)SBC
BGP Support for IP Prefix Import from Global Table into a VRF Table
The BGP Support for IP Prefix Import from Global Table into a VRF Table feature introduces the capability to import IPv4 unicast prefixes from the global routing table into a Virtual Private Network (VPN) routing/forwarding (VRF) instance table using an import route map.
BGP Support for IP Prefix Import from Global Table into a VRF Table
12.2(27)SBC
BGP Support for Named Extended Community Lists
The BGP Support for Named Extended Community Lists feature introduces the ability to configure extended community lists using names in addition to the existing numbered format.
12.2(27)SBC
BGP Support for Sequenced Entries in Extended Community Lists
The BGP Support for Sequenced Entries in Extended Community Lists feature introduces automatic sequencing of individual entries in BGP extended community lists. This feature also introduces the ability to remove or resequence extended community list entries without deleting the entire existing extended community list.
12.2(33)SRE
BGP PIC Edge for IP and MPLS-VPN
The BGP PIC Edge for IP and MPLS-VPN feature creates and stores a backup path in the routing information base (RIB) and in Cisco Express Forwarding, so that in case of a failure, the backup path can immediately take over, thus enabling subsecond failover.
12.2(33)SRE
BGP Best External
The BGP PIC Edge for IP and MPLS-VPN feature creates and stores a backup path in the routing information base and in Cisco Express Forwarding, so that in case of a failure, the backup path can immediately take over, thus enabling subsecond failover.
12.2(33)SRE
BGP Support for 4-Byte ASN
The BGP Support for 4-Byte ASN feature introduced support for 4-byte autonomous system numbers. Because of increased demand for autonomous system numbers, in January 2009 the IANA will start to allocate 4-byte autonomous system numbers in the range from 65536 to 4294967295.
Configuring a Basic BGP Network
Connecting to a Service Provider Using External BGP
12.2(33)SRC
BGP Graceful Restart per Neighbor
The BGP Graceful Restart per Neighbor feature enables or disables the BGP graceful restart capability for an individual BGP neighbor, including using peer session templates and BGP peer groups.
12.2(33)SRC
BGP MIB Support Enhancements
The BGP MIB Support Enhancements feature introduced support in the CISCO-BGP4-MIB for new SNMP notifications.
12.2(33)SRB
BGP Neighbor Policy
The BGP Neighbor Policy feature introduces new keywords to two existing commands to display information about local and inherited policies. When BGP neighbors use multiple levels of peer templates, it can be difficult to determine which policies are applied to the neighbor. Inherited policies are policies that the neighbor inherits from a peer-group or a peer-policy template.
12.2(33)SRB
BGP per Neighbor SoO Configuration
The BGP per neighbor SOO configuration feature simplifies the configuration of the site-of-origin (SoO) parameter. In previous releases, the SoO parameter is configured using an inbound route map that sets the SoO value during the update process. The per neighbor SoO configuration introduces two new commands that can be used under router configuration mode to set the SoO value.
12.2(33)SRB
BGP Route-Map Continue Support for an Outbound Policy
The BGP Route-Map Continue Support for an Outbound Policy feature introduces support for continue clauses to be applied to outbound route maps.
12.2(33)SRB
BGP Selective Address Tracking
The BGP Selective Address Tracking feature introduces the use of a route map for next-hop route filtering and fast session deactivation. Selective next-hop filtering uses a route map to selectively define routes to help resolve the BGP next hop, or a route map can be used to determine if a peering session with a BGP neighbor should be reset when a route to the BGP peer changes.
Configuring Advanced BGP Features
12.2(33)SRB
BGP Support for MTR
BGP support for MTR introduces a new configuration hierarchy and command-line interface (CLI) commands to support multi-topology routing (MTR) topologies. The new configuration hierarchy, or scope, can be implemented by BGP independently of MTR. MTR allows the configuration of service differentiation through class-based forwarding. MTR supports multiple unicast topologies and a separate multicast topology. A topology is a subset of the underlying network (or base topology) characterized by an independent set of Network Layer Reachability Information (NLRI).
In 12.2(33)SRB, this feature was introduced on the Cisco 7600 series routers.
12.2(33)SRB
BGP Support for the L2VPN Address Family
BGP support for the L2VPN address family introduces a BGP-based autodiscovery mechanism to distribute Layer 2 Virtual Private Network (L2VPN) endpoint provisioning information. BGP uses a separate L2VPN routing information base (RIB) to store endpoint provisioning information, which is updated each time any Layer 2 virtual forwarding instance (VFI) is configured. When BGP distributes the endpoint provisioning information in an update message to all its BGP neighbors, the endpoint information is used to set up a pseudowire mesh to support L2VPN-based services.
12.2(33)SRB
Multiprotocol BGP (MP-BGP) Support for the CLNS
The Multiprotocol BGP (MP-BGP) Support for CLNS feature provides the ability to scale Connectionless Network Service (CLNS) networks. The multiprotocol extensions of Border Gateway Protocol (BGP) add the ability to interconnect separate Open System Interconnection (OSI) routing domains without merging the routing domains, thus providing the capability to build very large OSI networks.
12.2(33)SRA
BGP MIB Support Enhancements
The BGP MIB Support Enhancements feature introduced support in the CISCO-BGP4-MIB for new SNMP notifications.
12.2(33)SRA
BGP Support for BFD
Bidirectional Forwarding Detection (BFD) is a detection protocol designed to provide fast forwarding path failure detection times for all media types, encapsulations, topologies, and routing protocols. In addition to fast forwarding path failure detection, BFD provides a consistent failure detection method for network administrators. Because the network administrator can use BFD to detect forwarding path failures at a uniform rate, rather than the variable rates for different routing protocol hello mechanisms, network profiling and planning will be easier, and reconvergence time will be consistent and predictable. The main benefit of implementing BFD for BGP is a significantly faster reconvergence time.
12.2(33)SRA
BGP Support for Dual AS Configuration for Network AS Migrations
The BGP Support for Dual AS Configuration for Network AS Migrations feature extends the functionality of the BGP Local-AS feature by providing additional autonomous-system path customization configuration options. The configuration of this feature is transparent to customer peering sessions, allowing the provider to merge two autonomous-systems without interrupting customer peering arrangements. Customer peering sessions can later be updated during a maintenance window or during other scheduled downtime.
12.2(33)SRA
BGP Support for Fast Peering Session Deactivation
The BGP Support for Fast Peering Session Deactivation feature introduced an event driven notification system that allows a Border Gateway Protocol (BGP) process to monitor BGP peering sessions on a per-neighbor basis. This feature improves the response time of BGP to adjacency changes by allowing BGP to detect an adjacency change and deactivate the terminated session in between standard BGP scanning intervals. Enabling this feature improves overall BGP convergence.
12.2(33)SRA
BGP Support for IP Prefix Import from Global Table into a VRF Table
The BGP Support for IP Prefix Import from Global Table into a VRF Table feature introduces the capability to import IPv4 unicast prefixes from the global routing table into a Virtual Private Network (VPN) routing/forwarding (VRF) instance table using an import route map.
BGP Support for IP Prefix Import from Global Table into a VRF Table
12.2(33)SRA
BGP Support for Named Extended Community Lists
The BGP Support for Named Extended Community Lists feature introduces the ability to configure extended community lists using names in addition to the existing numbered format.
12.2(33)SRA
BGP Support for Sequenced Entries in Extended Community Lists
The BGP Support for Sequenced Entries in Extended Community Lists feature introduces automatic sequencing of individual entries in BGP extended community lists. This feature also introduces the ability to remove or resequence extended community list entries without deleting the entire existing extended community list.
12.2(33)SRA
BGP Support for TCP Path MTU Discovery per Session
Border Gateway Protocol (BGP) support for Transmission Control Protocol (TCP) path maximum transmission unit (MTU) discovery introduced the ability for BGP to automatically discover the best TCP path MTU for each BGP session. The TCP path MTU is enabled by default for all BGP neighbor sessions, but you can disable, and subsequently enable, the TCP path MTU globally for all BGP sessions or for an individual BGP neighbor session.
12.2(33)SRA
Per-VRF Assignment of BGP Router ID
The Per-VRF Assignment of BGP Router ID feature introduces the ability to have VRF-to-VRF peering in Border Gateway Protocol (BGP) on the same router. BGP is designed to refuse a session with itself because of the router ID check. The per-VRF assignment feature allows a separate router ID per VRF using a new keyword in the existing bgp router-id command. The router ID can be manually configured for each VRF or can be assigned automatically either globally under address family configuration mode or for each VRF.
12.2(33)SXI1
BGP Support for 4-Byte ASN
The BGP Support for 4-Byte ASN feature introduced support for 4-byte autonomous system numbers. Because of increased demand for autonomous system numbers, in January 2009 the IANA will start to allocate 4-byte autonomous system numbers in the range from 65536 to 4294967295.
12.2(33)SXI
BGP Route-Map Continue Support for an Outbound Policy
The BGP Route-Map Continue Support for an Outbound Policy feature introduces support for continue clauses to be applied to outbound route maps.
12.2(33)SXH
BGP Dynamic Neighbors
BGP dynamic neighbor support allows BGP peering to a group of remote neighbors that are defined by a range of IP addresses. Each range can be configured as a subnet IP address. BGP dynamic neighbors are configured using a range of IP addresses and BGP peer groups. After a subnet range is configured for a BGP peer group and a TCP session is initiated for an IP address in the subnet range, a new BGP neighbor is dynamically created as a member of that group. The new BGP neighbor will inherit any configuration for the peer group. The output for three show commands has been updated to display information about dynamic neighbors.
12.2(33)SXH
BGP MIB Support Enhancements
The BGP MIB Support Enhancements feature introduced support in the CISCO-BGP4-MIB for new SNMP notifications.
12.2(33)SXH
BGP Support for BFD
Bidirectional Forwarding Detection (BFD) is a detection protocol designed to provide fast forwarding path failure detection times for all media types, encapsulations, topologies, and routing protocols. In addition to fast forwarding path failure detection, BFD provides a consistent failure detection method for network administrators. Because the network administrator can use BFD to detect forwarding path failures at a uniform rate, rather than the variable rates for different routing protocol hello mechanisms, network profiling and planning will be easier, and reconvergence time will be consistent and predictable. The main benefit of implementing BFD for BGP is a significantly faster reconvergence time.
12.2(33)SXH
BGP Support for Dual AS Configuration for Network AS Migrations
The BGP Support for Dual AS Configuration for Network AS Migrations feature extends the functionality of the BGP Local-AS feature by providing additional autonomous-system path customization configuration options. The configuration of this feature is transparent to customer peering sessions, allowing the provider to merge two autonomous-systems without interrupting customer peering arrangements. Customer peering sessions can later be updated during a maintenance window or during other scheduled downtime.
12.2(33)SXH
BGP Support for Fast Peering Session Deactivation
The BGP Support for Fast Peering Session Deactivation feature introduced an event driven notification system that allows a Border Gateway Protocol (BGP) process to monitor BGP peering sessions on a per-neighbor basis. This feature improves the response time of BGP to adjacency changes by allowing BGP to detect an adjacency change and deactivate the terminated session in between standard BGP scanning intervals. Enabling this feature improves overall BGP convergence.
12.2(33)SXH
BGP Support for IP Prefix Import from Global Table into a VRF Table
The BGP Support for IP Prefix Import from Global Table into a VRF Table feature introduces the capability to import IPv4 unicast prefixes from the global routing table into a Virtual Private Network (VPN) routing/forwarding (VRF) instance table using an import route map.
BGP Support for IP Prefix Import from Global Table into a VRF Table
12.2(33)SXH
BGP Support for Named Extended Community Lists
The BGP Support for Named Extended Community Lists feature introduces the ability to configure extended community lists using names in addition to the existing numbered format.
12.2(33)SXH
BGP Support for Next-Hop Address Tracking
The BGP Support for Next-Hop Address Tracking feature is enabled by default when a supporting Cisco IOS software image is installed. BGP next-hop address tracking is event driven. BGP prefixes are automatically tracked as peering sessions are established. Next-hop changes are rapidly reported to the BGP routing process as they are updated in the RIB. This optimization improves overall BGP convergence by reducing the response time to next-hop changes for routes installed in the RIB. When a bestpath calculation is run in between BGP scanner cycles, only next-hop changes are tracked and processed.
12.2(33)SXH
BGP Support for Sequenced Entries in Extended Community Lists
The BGP Support for Sequenced Entries in Extended Community Lists feature introduces automatic sequencing of individual entries in BGP extended community lists. This feature also introduces the ability to remove or resequence extended community list entries without deleting the entire existing extended community list.
12.2(33)SXH
BGP Support for TCP Path MTU Discovery per Session
Border Gateway Protocol (BGP) support for Transmission Control Protocol (TCP) path maximum transmission unit (MTU) discovery introduced the ability for BGP to automatically discover the best TCP path MTU for each BGP session. The TCP path MTU is enabled by default for all BGP neighbor sessions, but you can disable, and subsequently enable, the TCP path MTU globally for all BGP sessions or for an individual BGP neighbor session.
12.2(33)SXH
Per-VRF Assignment of BGP Router ID
The Per-VRF Assignment of BGP Router ID feature introduces the ability to have VRF-to-VRF peering in Border Gateway Protocol (BGP) on the same router. BGP is designed to refuse a session with itself because of the router ID check. The per-VRF assignment feature allows a separate router ID per VRF using a new keyword in the existing bgp router-id command. The router ID can be manually configured for each VRF or can be assigned automatically either globally under address family configuration mode or for each VRF.
12.2(33)SXH
Suppress BGP Advertisement for Inactive Routes
The Suppress BGP Advertisements for Inactive Routes feature allows you to configure the suppression of advertisements for routes that are not installed in the Routing Information Base (RIB). Configuring this feature allows Border Gateway Protocol (BGP) updates to be more consistent with data used for traffic forwarding.
12.2(18)SXE
BGP Multipath Load Sharing for eBGP and iBGP in an MPLs VPN
The BGP Multipath Load Sharing for eBGP and iBGP feature allows you to configure multipath load balancing with both external BGP (eBGP) and internal BGP (iBGP) paths in Border Gateway Protocol (BGP) networks that are configured to use Multiprotocol Label Switching (MPLS) Virtual Private Networks (VPNs). This feature provides improved load balancing deployment and service offering capabilities and is useful for multi-homed autonomous systems and Provider Edge (PE) routers that import both eBGP and iBGP paths from multihomed and stub networks.
12.2(18)SXE
BGP Support for TTL Security Check
The BGP Support for TTL Security Check feature introduced a lightweight security mechanism to protect external Border Gateway Protocol (eBGP) peering sessions from CPU utilization-based attacks using forged IP packets. Enabling this feature prevents attempts to hijack the eBGP peering session by a host on a network segment that is not part of either BGP network or by a host on a network segment that is not between the eBGP peers.
12.4(24)T
BGP Support for 4-Byte ASN
The BGP Support for 4-Byte ASN feature introduced support for 4-byte autonomous system numbers. Because of increased demand for autonomous system numbers, in January 2009 the IANA will start to allocate 4-byte autonomous system numbers in the range from 65536 to 4294967295.
12.4(20)T
BGP Support for TCP Path MTU Discovery per Session
Border Gateway Protocol (BGP) support for Transmission Control Protocol (TCP) path maximum transmission unit (MTU) discovery introduced the ability for BGP to automatically discover the best TCP path MTU for each BGP session. The TCP path MTU is enabled by default for all BGP neighbor sessions, but you can disable, and subsequently enable, the TCP path MTU globally for all BGP sessions or for an individual BGP neighbor session.
12.4(20)T
Per-VRF Assignment of BGP Router ID
The Per-VRF Assignment of BGP Router ID feature introduces the ability to have VRF-to-VRF peering in Border Gateway Protocol (BGP) on the same router. BGP is designed to refuse a session with itself because of the router ID check. The per-VRF assignment feature allows a separate router ID per VRF using a new keyword in the existing bgp router-id command. The router ID can be manually configured for each VRF or can be assigned automatically either globally under address family configuration mode or for each VRF.
12.4(11)T
BGP Neighbor Policy
The BGP Neighbor Policy feature introduces new keywords to two existing commands to display information about local and inherited policies. When BGP neighbors use multiple levels of peer templates, it can be difficult to determine which policies are applied to the neighbor. Inherited policies are policies that the neighbor inherits from a peer-group or a peer-policy template.
12.4(11)T
BGP per Neighbor SoO Configuration
The BGP per neighbor SOO configuration feature simplifies the configuration of the site-of-origin (SoO) parameter. In Cisco IOS Release 12.4(9)T, 12.2(33)SRA, and previous releases, the SoO parameter is configured using an inbound route map that sets the SoO value during the update process. The per neighbor SoO configuration introduces two new commands that can be used under router configuration mode to set the SoO value.
12.4(4)T
BGP Route-Map Continue Support for an Outbound Policy
The BGP Route-Map Continue Support for an Outbound Policy feature introduces support for continue clauses to be applied to outbound route maps.
12.4(4)T
BGP Selective Address Tracking
The BGP Selective Address Tracking feature introduces the use of a route map for next-hop route filtering and fast session deactivation. Selective next-hop filtering uses a route map to selectively define routes to help resolve the BGP next hop, or a route map can be used to determine if a peering session with a BGP neighbor should be reset when a route to the BGP peer changes.
Configuring Advanced BGP Features
12.4(4)T
BGP Support for BFD
Bidirectional Forwarding Detection (BFD) is a detection protocol designed to provide fast forwarding path failure detection times for all media types, encapsulations, topologies, and routing protocols. In addition to fast forwarding path failure detection, BFD provides a consistent failure detection method for network administrators. Because the network administrator can use BFD to detect forwarding path failures at a uniform rate, rather than the variable rates for different routing protocol hello mechanisms, network profiling and planning will be easier, and reconvergence time will be consistent and predictable. The main benefit of implementing BFD for BGP is a significantly faster reconvergence time.
12.3(14)T
BGP Support for Fast Peering Session Deactivation
The BGP Support for Fast Peering Session Deactivation feature introduced an event driven notification system that allows a Border Gateway Protocol (BGP) process to monitor BGP peering sessions on a per-neighbor basis. This feature improves the response time of BGP to adjacency changes by allowing BGP to detect an adjacency change and deactivate the terminated session in between standard BGP scanning intervals. Enabling this feature improves overall BGP convergence.
12.3(14)T
BGP Support for IP Prefix Import from Global Table into a VRF Table
The BGP Support for IP Prefix Import from Global Table into a VRF Table feature introduces the capability to import IPv4 unicast prefixes from the global routing table into a Virtual Private Network (VPN) routing/forwarding (VRF) instance table using an import route map.
BGP Support for IP Prefix Import from Global Table into a VRF Table
12.3(14)T
BGP Support for Next-Hop Address Tracking
The BGP Support for Next-Hop Address Tracking feature is enabled by default when a supporting Cisco IOS software image is installed. BGP next-hop address tracking is event driven. BGP prefixes are automatically tracked as peering sessions are established. Next-hop changes are rapidly reported to the BGP routing process as they are updated in the RIB. This optimization improves overall BGP convergence by reducing the response time to next-hop changes for routes installed in the RIB. When a bestpath calculation is run in between BGP scanner cycles, only next-hop changes are tracked and processed.
12.3(11)T
BGP Support for Dual AS Configuration for Network AS Migrations
The BGP Support for Dual AS Configuration for Network AS Migrations feature extends the functionality of the BGP Local-AS feature by providing additional autonomous-system path customization configuration options. The configuration of this feature is transparent to customer peering sessions, allowing the provider to merge two autonomous-systems without interrupting customer peering arrangements. Customer peering sessions can later be updated during a maintenance window or during other scheduled downtime.
12.3(11)T
BGP Support for Named Extended Community Lists
The BGP Support for Named Extended Community Lists feature introduces the ability to configure extended community lists using names in addition to the existing numbered format.
12.3(11)T
BGP Support for Sequenced Entries in Extended Community Lists
The BGP Support for Sequenced Entries in Extended Community Lists feature introduces automatic sequencing of individual entries in BGP extended community lists. This feature also introduces the ability to remove or resequence extended community list entries without deleting the entire existing extended community list.
12.3(8)T
BGP Cost Community Support for EIGRP MPLS VPN PE-CE
The BGP Cost Community Support for EIGRP MPLS VPN PE-CE feature provides BGP cost community support for mixed EIGRP MPLS VPN network topologies that contain back door routes.
12.3(7)T
BGP MIB Support Enhancements
The BGP MIB Support Enhancements feature introduced support in the CISCO-BGP4-MIB for new SNMP notifications.
12.3(7)T
BGP Support for TTL Security Check
The BGP Support for TTL Security Check feature introduced a lightweight security mechanism to protect external Border Gateway Protocol (eBGP) peering sessions from CPU utilization-based attacks using forged IP packets. Enabling this feature prevents attempts to hijack the eBGP peering session by a host on a network segment that is not part of either BGP network or by a host on a network segment that is not between the eBGP peers.
12.3(4)T
BGP Configuration Using Peer Templates
The BGP Configuration Using Peer Templates feature introduces a new mechanism that groups distinct neighbor configurations for BGP neighbors that share policies. Configuration templates provide an alternative to peer group configuration and overcome some of the limitations of peer groups.
12.3(4)T
BGP Dynamic Update Peer Groups
The BGP Dynamic Update Peer Groups feature introduces a new algorithm that dynamically calculates and optimizes update groups of neighbors that share outbound policies and can share update messages. In previous versions of Cisco IOS software, BGP update messages were grouped based on peer group configurations. This method of grouping updates limited outbound policies and specific-session configurations. The BGP Dynamic Update Peer Groups feature separates update group replication from peer group configuration, which improves convergence time and flexibility of neighbor configuration.
12.3(4)T
BGP Policy Accounting Output Interface Accounting
Border Gateway Protocol (BGP) policy accounting (PA) measures and classifies IP traffic that is sent to, or received from, different peers. Policy accounting was previously available on an input interface only. The BGP Policy Accounting Output Interface Accounting feature introduces several extensions to enable BGP PA on an output interface and to include accounting based on a source address for both input and output traffic on an interface. Counters based on parameters such as community list, autonomous system number, or autonomous system path are assigned to identify the IP traffic.
12.3(4)T
Regex Engine Performance Enhancement
The Regex Engine Performance Enhancement feature introduces a new regular expression engine that is designed to process complex regular expressions. This new regular expression engine does not replace the existing engine. The existing engine is preferred for simple regular expressions and is the default engine and in Cisco IOS software. Either engine can be selected from the command-line interface (CLI).
12.3(2)T
BGP Cost Community
The BGP Cost Community feature introduces the cost extended community attribute. The cost community is a non-transitive extended community attribute that is passed to internal BGP (iBGP) and confederation peers but not to external BGP (eBGP) peers. The cost community feature allows you to customize the local route preference and influence the best path selection process by assigning cost values to specific routes.
12.3(2)T
BGP Route-Map Continue
The BGP Route-Map Continue feature introduces the continue clause to BGP route map configuration. The continue clause allows for more programmable policy configuration and route filtering and introduces the capability to execute additional entries in a route map after an entry is executed with successful match and set clauses. Continue clauses allow the network operator to configure and organize more modular policy definitions so that specific policy configurations need not be repeated within the same route map.
12.3(2)T
Loadsharing IP Packets Over More Than Six Parallel Paths
The Loadsharing IP Packets Over More Than Six Parallel Paths feature increases the maximum number of parallel routes that can be installed to the routing table for multipath loadsharing.
12.2(15)T
BGP Hybrid CLI
The BGP Hybrid CLI feature simplifies the migration of BGP networks and existing configurations from the NLRI format to the AFI format. This new functionality allows the network operator to configure commands in the AFI format and save these command configurations to existing NLRI formatted configurations. The feature provides the network operator with the capability to take advantage of new features and provides support for migration from the NLRI format to the AFI format.
12.2(15)T
BGP Increased Support of Numbered AS-Path Access Lists to 500
The BGP Increased Support of Numbered AS-Path Access Lists to 500 feature increases the maximum number of autonomous systems access lists that can be configured using the ip as-path access-list command from 199 to 500.
12.2(15)T
BGP Nonstop Forwarding (NSF) Awareness
Nonstop Forwarding (NSF) awareness allows a router to assist NSF-capable neighbors to continue forwarding packets during a Stateful Switchover (SSO) operation. The BGP Nonstop Forwarding Awareness feature allows an NSF-aware router that is running BGP to forward packets along routes that are already known for a router that is performing an SSO operation. This capability allows the BGP peers of the failing router to retain the routing information that is advertised by the failing router and continue to use this information until the failed router has returned to normal operating behavior and is able to exchange routing information. The peering session is maintained throughout the entire NSF operation.
12.2(15)T
BGP Restart Session After Max-Prefix Limit
The BGP Restart Session After Max-Prefix Limit feature enhances the capabilities of the neighbor maximum-prefix command with the introduction of the restart keyword. This enhancement allows the network operator to configure the time interval at which a peering session is reestablished by a router when the number of prefixes that have been received from a peer has exceeded the maximum prefix limit.
12.2(15)T
BGP Route-Map Policy List Support
The BGP Route-Map Policy List Support feature introduces new functionality to BGP route maps. This feature adds the capability for a network operator to group route map match clauses into named lists called policy lists. A policy list functions like a macro. When a policy list is referenced in a route map, all of the match clauses are evaluated and processed as if they had been configured directly in the route map. This enhancement simplifies the configuration of BGP routing policy in medium-size and large networks because a network operator can preconfigure policy lists with groups of match clauses and then reference these policy lists within different route maps. The network operator no longer needs to manually reconfigure each recurring group of match clauses that occur in multiple route map entries.
12.2(13)T
BGP Policy Accounting
Border Gateway Protocol (BGP) policy accounting measures and classifies IP traffic that is sent to, or received from, different peers. Policy accounting is enabled on an input interface, and counters based on parameters such as community list, autonomous system number, or autonomous system path are assigned to identify the IP traffic.
12.2(8)T
BGP Named Community Lists
The BGP Named Community Lists feature introduces a new type of community list called the named community list. The BGP Named Community Lists feature allows the network operator to assign meaningful names to community lists and increases the number of community lists that can be configured. A named community list can be configured with regular expressions and with numbered community lists. All rules of numbered communities apply to named community lists except that there is no limitation on the number of community attributes that can be configured for a named community list.
12.2(8)T
Multiprotocol BGP (MP-BGP) Support for the CLNS
The Multiprotocol BGP (MP-BGP) Support for CLNS feature provides the ability to scale Connectionless Network Service (CLNS) networks. The multiprotocol extensions of Border Gateway Protocol (BGP) add the ability to interconnect separate Open System Interconnection (OSI) routing domains without merging the routing domains, thus providing the capability to build very large OSI networks.
12.2(4)T
BGP Conditional Route Injection
The BGP Conditional Route Injection feature allows you to inject more specific prefixes into a BGP routing table over less specific prefixes that were selected through normal route aggregation. These more specific prefixes can be used to provide a finer granularity of traffic engineering or administrative control than is possible with aggregated routes.
12.2(4)T
BGP Multipath Load Sharing for eBGP and iBGP in an MPLs VPN
The BGP Multipath Load Sharing for eBGP and iBGP feature allows you to configure multipath load balancing with both external BGP (eBGP) and internal BGP (iBGP) paths in Border Gateway Protocol (BGP) networks that are configured to use Multiprotocol Label Switching (MPLS) Virtual Private Networks (VPNs). This feature provides improved load balancing deployment and service offering capabilities and is useful for multi-homed autonomous systems and Provider Edge (PE) routers that import both eBGP and iBGP paths from multihomed and stub networks.
12.2(4)T
BGP Prefix-Based Outbound Route Filtering
The BGP Prefix-Based Outbound Route Filtering feature uses BGP ORF send and receive capabilities to minimize the number of BGP updates that are sent between BGP peers. Configuring this feature can help reduce the number of system resources required for generating and processing routing updates by filtering out unwanted routing updates at the source. For example, this feature can be used to reduce the amount of processing required on a router that is not accepting full routes from a service provider network.
12.2(2)T
BGP Link Bandwidth
The Border Gateway Protocol (BGP) Link Bandwidth feature is used to advertise the bandwidth of an autonomous system exit link as an extended community. This feature is configured for links between directly connected external BGP (eBGP) neighbors. The link bandwidth extended community attribute is propagated to iBGP peers when extended community exchange is enabled. This feature is used with BGP multipath features to configure load balancing over links with unequal bandwidth.
12.2(2)T
iBGP Multipath Load Sharing
The iBGP Multipath Load Sharing feature enables the BGP speaking router to select multiple iBGP paths as the best paths to a destination. The best paths or multipaths are then installed in the IP routing table of the router.
15.1(2)T
BGP—Remove / Replace Private AS
Private autonomous system numbers (ASNs) are used by ISPs and customer networks to conserve globally unique AS numbers. Private AS numbers cannot be used to access the global Internet because they are not unique. AS numbers appear in eBGP AS paths in routing updates. Removing private ASNs from the AS path is necessary if you have been using private ASNs and you want to access the global Internet.
15.0(1)S
BGP—Remove / Replace Private AS
Private autonomous system numbers (ASNs) are used by ISPs and customer networks to conserve globally unique AS numbers. Private AS numbers cannot be used to access the global Internet because they are not unique. AS numbers appear in eBGP AS paths in routing updates. Removing private ASNs from the AS path is necessary if you have been using private ASNs and you want to access the global Internet.
15.0(1)S
BGP Slow Peer
The BGP Slow Peer feature allows a network administrator to detect a BGP slow peer and also to configure a peer as a slow peer statically or to dynamically mark it. Slow peer detection identifies a peer that is not transmitting update messages within a configured amount of time. Slow peer configuration moves or splits the peer from its normal update group to a slow update group, thus allowing the normal update group to function without being slowed down and to converge quickly.
15.0(1)S
BGP Dynamic Neighbors
BGP dynamic neighbor support allows BGP peering to a group of remote neighbors that are defined by a range of IP addresses. Each range can be configured as a subnet IP address. BGP dynamic neighbors are configured using a range of IP addresses and BGP peer groups. After a subnet range is configured for a BGP peer group and a TCP session is initiated for an IP address in the subnet range, a new BGP neighbor is dynamically created as a member of that group. The new BGP neighbor will inherit any configuration for the peer group.
15.0(1)S
BGP Support for Nonstop Routing (NSR) with Stateful Switchover (SSO) and In-Service Software Upgrade (ISSU)
The BGP Support for Nonstop Routing (NSR) with Stateful Switchover (SSO) feature enables provider edge (PE) routers to maintain BGP state with customer edge (CE) routers and ensure continuous packet forwarding during a Route Processor (RP) switchover or during a planned In-Service Software Upgrade (ISSU) for a PE router.
BGP Support for Nonstop Routing (NSR) with Stateful Switchover (SSO)
15.1(1)S
BGP: RT Constrained Route Distribution
BGP: Route Target (RT) Constrained Route Distribution is a feature that service providers can use in MPLS L3VPNs to reduce the number of unnecessary routing updates that route reflectors (RRs) send to RRs and PEs. The reduction in updates saves resources.
15.1(2)S
BGP Consistency Checker
The BGP Consistency Checker feature provides a way to identify certain types of BGP route inconsistencies with peers: next-hop label inconsistency, RIB-out inconsistency, and aggregation inconsistency. Upon finding such an inconsistency, the system sends a syslog error message and takes appropriate action if configured to do so.
15.1(2)S
BGP IPv6 Client for Single Hop BFD
Bidirectional Forwarding Detection (BFD) can be used to track fast forwarding path failure of BGP neighbors that have an IPv6 address. BFD is a detection protocol that is designed to provide fast forwarding path failure detection times for all media types, encapsulations, topologies, and routing protocols. BFD provides faster reconvergence time for BGP after a forwarding path failure.
15.1(2)S
BGP IPv6 PIC Edge and Core for IP/MPLS
The BGP IPv6 PIC Edge for IP MPLS feature improves convergence after a network failure. This convergence is applicable to both core and edge failures. The BGP IPv6 prefix-independent convergence (PIC) edge for IP MPLS feature creates and stores a backup or alternate path in the routing information base (RIB), forwarding information base (FIB), and in Cisco Express Forwarding, so that when a failure is detected, the backup or lternate path can immediately take over, thus enabling fast failover.
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