add-paths
To enable the Enhanced Interior Gateway Routing Protocol (EIGRP) to advertise multiple best paths to connected spokes in a Dynamic Multipoint VPN (DMVPN) domain, use the add-paths command in address family interface configuration mode. To disable this configuration, use the no form of this command.
add-paths number
no add-paths
Syntax Description
number |
Number of additional paths that are advertised as best paths to connected spokes. The range is from 1 to 4. |
Command Default
Only one path is advertised as the best path to spokes in a DMVPN domain.
Command Modes
Address family interface configuration (config-router-af-interface)
Command History
Release |
Modification |
---|---|
Cisco IOS XE Release 3.8S |
This command was introduced. |
15.3(1)S |
This command was integrated into Cisco IOS Release 15.3(1)S. |
15.3(2)T |
This command was integrated into Cisco IOS Release 15.3(2)T. |
Usage Guidelines
You can configure the add-paths command on hub interfaces that connect to spokes in a DMVPN domain to enable EIGRP to advertise multiple best paths to a destination. However, before you configure this command, ensure that the next-hop-self command is disabled on the hub interfaces. All interfaces in an EIGRP topology are by default configured with the next-hop-self command. This command enables EIGRP to set the local outbound interface as the next-hop value while advertising a route to a peer, even when advertising routes out of the interface on which the routes were learned. This default EIGRP behavior may interfere with the behavior of the add-paths command. To change this default setting, you must use the no next-hop-self interface configuration command to instruct EIGRP to use the received next-hop value when advertising routes back from the interface on which the routes were learned.
Examples
The following example shows how to configure a hub device to advertise additional IPv4 and IPv6 best paths to a destination in an EIGRP-enabled DMVPN domain:
Device(config)# router eigrp name
Device(config-router)# address-family ipv4 autonomous-system 2
Device(config-router-af)# af-interface tunnel0
Device(config-router-af-interface)# no next-hop-self no-ecmp-mode
Device(config-router-af-interface)# add-paths 3
Device(config-router-af-interface)# end
Device# configure terminal
Device(config)# ipv6 unicast-routing
Device(config)# router eigrp name
Device(config-router)# address-family ipv6 autonomous-system 2
Device(config-router-af)# af-interface tunnel0
Device(config-router-af-interface)# no next-hop-self no-ecmp-mode
Device(config-router-af-interface)# add-paths 4
Device(config-router-af-interface)# end
The following sample output from the show running-config command displays the EIGRP additional-paths configuration on the hub device:
Device# show running-config | section eigrp
router eigrp name
!
address-family ipv4 unicast autonomous-system 2
!
af-interface tunnel0
no next-hop-self no-ecmp-mode
add-path 3
exit-af-interface
router eigrp name
!
address-family ipv6 unicast autonomous-system 2
!
af-interface tunnel0
no next-hop-self no-ecmp-mode
add-path 4
exit-af-interface