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bgp additional path cisco XR

sachin30720041
Beginner
Beginner

Hello All,

I have configured the following setup.

XR1 and XR2 has ebgp session.

XR1 and XR3 has ebgp session.

XR2,XR3, XR4 and XR5 are ibgp neighbors. XR4 is the RR.

 

                     XR1

              /.              \

         XR2                XR3

           \                   /

                 XR4

                   |

                 XR5

XR1 is advertising 1.1.1.1.

I have configure bgp additional path on XR4 and XR5 so that XR5 has multiple paths for 1.1.1.1.

 

XRV4
-----------------------------------------
int gi0/0/0/1
ip address 100.20.40.4 255.255.255.0
no sh

int gi0/0/0/0
ip address 100.30.40.4 255.255.255.0
no sh

int gi0/0/0/2
ip address 100.40.50.4 255.255.255.0
no sh

int lo0
ip address 4.4.4.4 255.255.255.255
exit

router bgp 12
address-family ipv4 unicast

additional-paths send
exit
session-group session1
remote-as 12
update-source lo0
exit
af-group af1 address-family ipv4 unicast
route-reflector-client
exit
neighbor 2.2.2.2
use session-group session1
address-family ipv4 unicast
use af-group af1
exit
neighbor 3.3.3.3
use session-group session1
address-family ipv4 unicast
use af-group af1
exit
neighbor 5.5.5.5
use session-group session1
address-family ipv4 unicast
use af-group af1
exit

router ospf 1
area 0
int gi0/0/0/1
int gi0/0/0/0
int gi0/0/0/2
int lo0
exit

XRV5
-----------------------------------------
int gi0/0/0/2
ip address 100.40.50.5 255.255.255.0
no sh

int lo0
ip address 5.5.5.5 255.255.255.255
exit

router bgp 12
address-family ipv4 unicast
additional-paths receive
exit
session-group session1
remote-as 12
update-source lo0
exit
neighbor 4.4.4.4
use session-group session1
address-family ipv4 unicast
exit

router ospf 1
area 0
int gi0/0/0/2
int lo0
exit

 

But still, I see only one path on XRV5. I am not sure what configuration am I missing ?

RP/0/0/CPU0:ios#show bgp ipv4 unicast
Network                     Next Hop              Metric                LocPrf           Weight            Path
*>i1.1.1.1/32                2.2.2.2                  0                     100                  0                   1 i

Processed 1 prefixes, 1 paths

 

Thanks,

Sachin

1 ACCEPTED SOLUTION

Accepted Solutions

Harold Ritter
Cisco Employee
Cisco Employee

Hi @sachin30720041 ,

 

Make sure you configure the following:

XR2 & XR3:

router bgp 12
address-family ipv4 unicast
additional-paths send
advertise best-external
additional-paths selection route-policy ADD-PATH
!
!
route-policy ADD-PATH
set path-selection all advertise
end-policy
!

XR4:

router bgp 12
address-family ipv4 unicast
additional-paths send

additional-paths receive
additional-paths selection route-policy ADD-PATH
!
!
route-policy ADD-PATH
set path-selection all advertise
end-policy
!

 

 

Regards,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México

View solution in original post

4 REPLIES 4

MHM Cisco World
Advisor
Advisor

check my below comment 

Harold Ritter
Cisco Employee
Cisco Employee

Hi @sachin30720041 ,

 

Make sure you configure the following:

XR2 & XR3:

router bgp 12
address-family ipv4 unicast
additional-paths send
advertise best-external
additional-paths selection route-policy ADD-PATH
!
!
route-policy ADD-PATH
set path-selection all advertise
end-policy
!

XR4:

router bgp 12
address-family ipv4 unicast
additional-paths send

additional-paths receive
additional-paths selection route-policy ADD-PATH
!
!
route-policy ADD-PATH
set path-selection all advertise
end-policy
!

 

 

Regards,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México

MHM Cisco World
Advisor
Advisor

check my below comment 

MHM Cisco World
Advisor
Advisor

I do the lab months ago and not success and when you make your post I return and read that RR not prefer for additional-paths!!
I thinking why what ?
I previous do all command but still no luck.
until I figure out the issue, 
previous lab I add next-hop-self in RR, 
RR client see two identical prefix path with same next-hop and that why RR client failed to add two path no ONE because there is no meaning of had two path through same next-hop.
anyway after I remove the next-hop-self I success to get two path.
kjkkjkjkjkjkjk.pngnbmnbnmbnmbmn.pngALL keyword add beside the second pathkkkkkkkk.png multipath "m" keyword add to both prefix 

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