3-1-1. Cisco dual BGP with Metric (Redundancy)

Outbound traffic on CPE

All outbound traffic will go out thru primary line(12.1.3.1) due to route-map shadow_inbound tag local-pref 80 on default route from bgp peer(12.1.4.2)

 

Inbound traffic  on CPE

All inbound traffic will come in thru primary line (12.1.3.1) due to route-map shadow_outbound tag metric 200 on announced IP route.

 

[CPE/Customer Cisco Router]

Current configuration:
!
version 12.x
!
hostname CPE
!
interface Ethernet0
description to Internal network
ip address 10.1.0.1 255.255.255.0

ip address 10.1.0.129 255.255.255.128 secondary

no ip directed-broadcast
no ip mroute-cache
!
interface Serial0
description to ISP A - WAN 1
ip address 12.1.3.1 255.255.255.252
no ip directed-broadcast
no ip mroute-cache
no fair-queue
!
interface Serial1
description to ISP A - WAN 2

ip address 12.1.4.1 255.255.255.252
no ip directed-broadcast
no ip mroute-cache
no fair-queue
!
router bgp 10
no auto-summary

network 10.1.0.0 mask 255.255.255.0

neighbor 12.1.3.2 remote-as 20
neighbor 12.1.3.2 version 4
neighbor 12.1.4.2 remote-as 20
neighbor 12.1.4.2 version 4

neighbor 12.1.4.2 prefix-list 1 out
neighbor 12.1.4.2 route-map shadow_inbound in

neighbor 12.1.4.2 route-map shadow_outbound out

!
ip classless
!

ip prefix-list 1 seq 5 permit 10.1.0.0/24 le 32

!
route-map shadow_inbound permit 10

set local-preference 80

!

route-map shadow_outbound permit 10

set metric 200
!
!
line con 0
line aux 0
line vty 0 4
login
!
end

  

[PE1 / ISP Cisco Router]

Current configuration:
!
version 12.x
!
hostname PE

!
!
interface Serial0
description to WAN 1
ip address 12.1.3.2 255.255.255.252
no ip directed-broadcast
no ip mroute-cache
no fair-queue
!

router bgp 20
no auto-summary
neighbor 12.1.3.1 remote-as 10
neighbor 12.1.3.1 version 4
neighbor 12.1.3.1 default-originate <---to send a default route

neighbor 12.1.3.1 distribute-list 2 out
!
ip classless
!

access-list 2 permit 100.100.100.0 0.0.0.255

! 

line con 0
line aux 0
line vty 0 4
login
!
end

 

 

 

[PE2 / ISP Cisco Router]

 

Current configuration:
!
version 12.x
!
hostname PE

!
!
interface Serial1
description to WAN 2

ip address 12.1.4.2 255.255.255.252
no ip mroute-cache
no ip directed-broadcast
no fair-queue
!

router bgp 20
no auto-summary
neighbor 12.1.4.1 remote-as 10
neighbor 12.1.4.1 version 4
neighbor 12.1.4.1 default-originate <---to send a default route

neighbor 12.1.4.1 distribute-list 2 out
!
ip classless
!

access-list 2 permit 100.100.100.0 0.0.0.255
!
line con 0
line aux 0
line vty 0 4
login
!
end

[Verifing output]

CPE# show ip bgp neighbors 12.1.3.2 ad
BGP table version is 4, local router ID is 1.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 10.1.0.0/24      0.0.0.0                  0         32768 i

Total number of prefixes 1
CPE#
 

 

CPE# show ip bgp neighbors 12.1.4.2 ad

CPE1#sh ip bgp neighbors 12.1.4.2 ad
BGP table version is 4, local router ID is 1.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 10.1.0.0/24      0.0.0.0                  0         32768 i

Total number of prefixes 1
CPE#

 

 

CPE# show ip bgp neighbors 12.1.3.2 ro

BGP table version is 4, local router ID is 1.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 0.0.0.0          12.1.3.2                 0             0 20 i
*> 100.100.100.0/24 12.1.3.2                               0 20 ?

Total number of prefixes 2
CPE#

 

 

CPE# show ip bgp neighbors 12.1.4.2 ro

BGP table version is 4, local router ID is 1.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*  0.0.0.0          12.1.4.2                 0     80      0 20 i
*  100.100.100.0/24 12.1.4.2                       80      0 20 ?

Total number of prefixes 2
CPE#

 

PE1#show ip bgp nei 12.1.3.1 ro

BGP table version is 33, local router ID is 3.3.3.3
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 10.1.0.0/24      12.1.3.1                 0             0 10 i

Total number of prefixes 1
PE1#

 

 

PE2#show ip bgp nei 12.1.4.1 ro
BGP table version is 44, local router ID is 4.4.4.4
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 10.1.0.0/24      12.1.4.1               200             0 10 i

Total number of prefixes 1
PE2#

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