They exchange labels and prefixes for Loopback addresses
Remote Loopbacks are redistributed into IGP at the ASBR
RRs establish VPNv4 BGP session to exchange VPN Prefixes and Labels
Packet in the Inter-AS link has two labels (VPN label and Transport Label )
Initial Configurations
AS 1 Routers
PE1
!
hostname PE1
vrf definition A
rd 1:1
!
address-family ipv4
route-target export 1:1
route-target import 1:1
exit-address-family
!
vrf definition B
rd 1:2
!
address-family ipv4
route-target export 1:2
route-target import 1:2
exit-address-family
!
mpls label protocol ldp
!
interface Loopback0
ip address 11.11.11.11 255.255.255.255
ip ospf 1 area 0
!
interface GigabitEthernet1
mtu 1600
ip address 10.11.12.11 255.255.255.0
ip ospf network point-to-point
ip ospf 1 area 0
no shutdown
!
interface GigabitEthernet2
vrf forwarding A
ip address 172.16.1.1 255.255.255.252
no shutdown
!
interface GigabitEthernet3
vrf forwarding B
ip address 172.16.1.5 255.255.255.252
no shutdown
!
router ospf 1
router-id 11.11.11.11
passive-interface default
no passive-interface GigabitEthernet1
mpls ldp sync
mpls ldp autoconfig area 0
!
router bgp 1
bgp router-id 11.11.11.11
bgp log-neighbor-changes
no bgp default ipv4-unicast
neighbor 13.13.13.13 remote-as 1
neighbor 13.13.13.13 update-source Loopback0
!
address-family ipv4
exit-address-family
!
address-family vpnv4
neighbor 13.13.13.13 activate
neighbor 13.13.13.13 send-community extended
exit-address-family
!
address-family ipv4 vrf A
redistribute connected
neighbor 172.16.1.2 remote-as 65101
neighbor 172.16.1.2 activate
exit-address-family
!
address-family ipv4 vrf B
redistribute connected
neighbor 172.16.1.6 remote-as 65201
neighbor 172.16.1.6 activate
exit-address-family
!
mpls ldp router-id Loopback0
!
P1
!
hostname P1
!
mpls label protocol ldp
!
interface Loopback0
ip address 12.12.12.12 255.255.255.255
ip ospf 1 area 0
!
interface GigabitEthernet1
mtu 1600
ip address 10.11.12.12 255.255.255.0
ip ospf network point-to-point
ip ospf 1 area 0
no shutdown
!
interface GigabitEthernet2
mtu 1600
ip address 10.12.13.12 255.255.255.0
ip ospf network point-to-point
ip ospf 1 area 0
no shutdown
interface GigabitEthernet3
mtu 1600
ip address 10.12.14.12 255.255.255.0
ip ospf network point-to-point
ip ospf 1 area 0
no shutdown
!
router ospf 1
router-id 12.12.12.12
passive-interface default
no passive-interface GigabitEthernet1
no passive-interface GigabitEthernet2
no passive-interface GigabitEthernet3
mpls ldp sync
mpls ldp autoconfig area 0
!
mpls ldp router-id Loopback0
!
RR1
VPNv4 Peering with ASBR1 is not required assuming no CEs connected to it.
!
hostname RR1
!
mpls label protocol ldp
!
interface Loopback0
ip address 13.13.13.13 255.255.255.255
ip ospf 1 area 0
!
interface GigabitEthernet1
mtu 1600
ip address 10.12.13.13 255.255.255.0
ip ospf network point-to-point
ip ospf 1 area 0
no shutdown
!
router ospf 1
router-id 13.13.13.13
passive-interface default
no passive-interface GigabitEthernet1
mpls ldp sync
mpls ldp autoconfig area 0
!
router bgp 1
bgp router-id 13.13.13.13
bgp log-neighbor-changes
no bgp default ipv4-unicast
neighbor 11.11.11.11 remote-as 1
neighbor 11.11.11.11 update-source Loopback0
!
address-family ipv4
exit-address-family
!
address-family vpnv4
neighbor 11.11.11.11 activate
neighbor 11.11.11.11 send-community extended
neighbor 11.11.11.11 route-reflector-client
exit-address-family
!
mpls ldp router-id Loopback0
!
ASBR1
!
hostname ASBR1
!
mpls label protocol ldp
1
interface Loopback0
ip address 14.14.14.14 255.255.255.255
ip ospf 1 area 0
!
interface GigabitEthernet1
mtu 1600
ip address 10.12.14.14 255.255.255.0
ip ospf network point-to-point
ip ospf 1 area 0
no shutdown
!
router ospf 1
router-id 14.14.14.14
passive-interface default
no passive-interface GigabitEthernet1
mpls ldp sync
mpls ldp autoconfig area 0
!
mpls ldp router-id Loopback0
AS 2 Routers
PE2
!
hostname PE2
vrf definition A
rd 1:1
!
address-family ipv4
route-target export 1:1
route-target import 1:1
exit-address-family
!
vrf definition B
rd 1:2
!
address-family ipv4
route-target export 1:2
route-target import 1:2
exit-address-family
!
mpls label protocol ldp
!
interface Loopback0
ip address 21.21.21.21 255.255.255.255
ip ospf 1 area 0
!
interface GigabitEthernet1
mtu 1600
ip address 20.11.12.11 255.255.255.0
ip ospf network point-to-point
ip ospf 1 area 0
no shutdown
!
interface GigabitEthernet2
vrf forwarding A
ip address 172.16.2.1 255.255.255.252
no shutdown
!
interface GigabitEthernet3
vrf forwarding B
ip address 172.16.2.5 255.255.255.252
no shutdown
!
router ospf 2
router-id 21.21.21.21
passive-interface default
no passive-interface GigabitEthernet1
mpls ldp sync
mpls ldp autoconfig area 0
!
router bgp 2
bgp router-id 21.21.21.21
bgp log-neighbor-changes
no bgp default ipv4-unicast
neighbor 23.23.23.23 remote-as 2
neighbor 23.23.23.23 update-source Loopback0
!
address-family ipv4
exit-address-family
!
address-family vpnv4
neighbor 23.23.23.23 activate
neighbor 23.23.23.23 send-community extended
exit-address-family
!
address-family ipv4 vrf A
redistribute connected
neighbor 172.16.2.2 remote-as 65102
neighbor 172.16.2.2 activate
exit-address-family
!
address-family ipv4 vrf B
redistribute connected
neighbor 172.16.2.6 remote-as 65202
neighbor 172.16.2.6 activate
exit-address-family
!
mpls ldp router-id Loopback0
!
P2
!
hostname P2
!
mpls label protocol ldp
!
interface Loopback0
ip address 22.22.22.22 255.255.255.255
ip ospf 2 area 0
!
interface GigabitEthernet1
mtu 1600
ip address 20.21.22.22 255.255.255.0
ip ospf network point-to-point
ip ospf 2 area 0
no shutdown
!
interface GigabitEthernet2
mtu 1600
ip address 20.22.23.22 255.255.255.0
ip ospf network point-to-point
ip ospf 2 area 0
no shutdown
interface GigabitEthernet3
mtu 1600
ip address 20.22.24.22 255.255.255.0
ip ospf network point-to-point
ip ospf 2 area 0
no shutdown
!
router ospf 2
router-id 22.22.22.22
passive-interface default
no passive-interface GigabitEthernet1
no passive-interface GigabitEthernet2
no passive-interface GigabitEthernet3
mpls ldp sync
mpls ldp autoconfig area 0
!
mpls ldp router-id Loopback0
!
RR2
VPNv4 Peering with ASBR2 is not required assuming no CEs connected to it.
!
hostname RR2
!
mpls label protocol ldp
!
interface Loopback0
ip address 23.23.23.23 255.255.255.255
ip ospf 2 area 0
!
interface GigabitEthernet1
mtu 1600
ip address 20.22.23.23 255.255.255.0
ip ospf network point-to-point
ip ospf 2 area 0
no shutdown
!
router ospf 1
router-id 23.23.23.23
passive-interface default
no passive-interface GigabitEthernet1
mpls ldp sync
mpls ldp autoconfig area 0
!
router bgp 2
bgp router-id 23.23.23.23
bgp log-neighbor-changes
no bgp default ipv4-unicast
neighbor 21.21.21.21 remote-as 2
neighbor 21.21.21.21 update-source Loopback0
!
address-family ipv4
exit-address-family
!
address-family vpnv4
neighbor 21.21.21.21 activate
neighbor 21.21.21.21 send-community extended
neighbor 21.21.21.21 route-reflector-client
exit-address-family
!
mpls ldp router-id Loopback0
!
ASBR2
!
hostname ASBR2
!
mpls label protocol ldp
!
interface Loopback0
ip address 24.24.24.24 255.255.255.255
ip ospf 2 area 0
!
interface GigabitEthernet1
mtu 1600
ip address 20.22.24.24 255.255.255.0
ip ospf network point-to-point
ip ospf 2 area 0
no shutdown
!
router ospf 2
router-id 24.24.24.24
passive-interface default
no passive-interface GigabitEthernet1
mpls ldp sync
mpls ldp autoconfig area 0
!
mpls ldp router-id Loopback0
!
Inter-AS Configuration
VRFs and Interfaces
VRFs are not required on the ASBRs
ASBR1
interface GigabitEthernet2
mtu 1600
ip address 172.16.0.1 255.255.255.252
negotiation auto
mpls bgp forwarding
no shutdown
ASBR2
interface GigabitEthernet2
mtu 1600
ip address 172.16.0.2 255.255.255.252
negotiation auto
mpls bgp forwarding
no shutdown
Inter-AS BGP
Local PE Loopback 0 addresses are advertised to the remote ASBR in the IPv4 LU AF.
ASBR1#show bgp ipv4 unicast summary | beg Nei
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
172.16.0.2 4 2 154 155 7 0 0 02:16:10 3
ASBR1#show bgp ipv4 unicast
BGP table version is 7, local router ID is 14.14.14.14
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
t secondary path, L long-lived-stale,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
*> 11.11.11.11/32 10.12.14.12 3 32768 i
*> 13.13.13.13/32 10.12.14.12 3 32768 i
*> 14.14.14.14/32 0.0.0.0 0 32768 i
*> 21.21.21.21/32 172.16.0.2 3 0 2 i
*> 23.23.23.23/32 172.16.0.2 3 0 2 i
*> 24.24.24.24/32 172.16.0.2 0 0 2 i
ASBR1#
ASBR1#show bgp labels
% Command accepted but obsolete, unreleased or unsupported; see documentation.
Network Next Hop In label/Out label
11.11.11.11/32 10.12.14.12 19/nolabel
13.13.13.13/32 10.12.14.12 17/nolabel
14.14.14.14/32 0.0.0.0 imp-null/nolabel
21.21.21.21/32 172.16.0.2 nolabel/21
23.23.23.23/32 172.16.0.2 nolabel/20
24.24.24.24/32 172.16.0.2 nolabel/imp-null
ASBR1#show mpls forwarding-table
Local Outgoing Prefix Bytes Label Outgoing Next Hop
Label Label or Tunnel Id Switched interface
16 Pop Label 172.16.0.2/32 0 Gi2 172.16.0.2
17 18 13.13.13.13/32 12238057 Gi1 10.12.14.12
18 Pop Label 12.12.12.12/32 0 Gi1 10.12.14.12
19 16 11.11.11.11/32 12200000 Gi1 10.12.14.12
20 Pop Label 10.12.13.0/24 0 Gi1 10.12.14.12
21 Pop Label 10.11.12.0/24 0 Gi1 10.12.14.12
30 21 21.21.21.21/32 10214572 Gi2 172.16.0.2
31 20 23.23.23.23/32 14221610 Gi2 172.16.0.2
ASBR1#
ASBR2
ASBR2#show bgp ipv4 unicast summary | beg Nei
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
172.16.0.1 4 1 157 156 13 0 0 02:17:44 3
ASBR2#show bgp ipv4 unicast
BGP table version is 13, local router ID is 24.24.24.24
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
t secondary path, L long-lived-stale,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
*> 11.11.11.11/32 172.16.0.1 3 0 1 i
*> 13.13.13.13/32 172.16.0.1 3 0 1 i
*> 14.14.14.14/32 172.16.0.1 0 0 1 i
*> 21.21.21.21/32 20.22.24.22 3 32768 i
*> 23.23.23.23/32 20.22.24.22 3 32768 i
*> 24.24.24.24/32 0.0.0.0 0 32768 i
ASBR2#
ASBR2#
ASBR2#show bgp labels
% Command accepted but obsolete, unreleased or unsupported; see documentation.
Network Next Hop In label/Out label
11.11.11.11/32 172.16.0.1 nolabel/19
13.13.13.13/32 172.16.0.1 nolabel/17
14.14.14.14/32 172.16.0.1 nolabel/imp-null
21.21.21.21/32 20.22.24.22 21/nolabel
23.23.23.23/32 20.22.24.22 20/nolabel
24.24.24.24/32 0.0.0.0 imp-null/nolabel
ASBR2#show mpls forwarding-table
Local Outgoing Prefix Bytes Label Outgoing Next Hop
Label Label or Tunnel Id Switched interface
16 Pop Label 172.16.0.1/32 0 Gi2 172.16.0.1
17 Pop Label 22.22.22.22/32 0 Gi1 20.22.24.22
18 Pop Label 20.22.23.0/24 0 Gi1 20.22.24.22
19 Pop Label 20.21.22.0/24 0 Gi1 20.22.24.22
20 17 23.23.23.23/32 14222423 Gi1 20.22.24.22
21 18 21.21.21.21/32 10214572 Gi1 20.22.24.22
22 19 11.11.11.11/32 12200000 Gi2 172.16.0.1
23 17 13.13.13.13/32 12238468 Gi2 172.16.0.1
ASBR2#
RR1
RR1#show ip route ospf | beg Gateway
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
O 10.11.12.0/24 [110/2] via 10.12.13.12, 02:41:27, GigabitEthernet1
O 10.12.14.0/24 [110/2] via 10.12.13.12, 02:41:27, GigabitEthernet1
11.0.0.0/32 is subnetted, 1 subnets
O 11.11.11.11 [110/3] via 10.12.13.12, 02:41:25, GigabitEthernet1
12.0.0.0/32 is subnetted, 1 subnets
O 12.12.12.12 [110/2] via 10.12.13.12, 02:41:27, GigabitEthernet1
14.0.0.0/32 is subnetted, 1 subnets
O 14.14.14.14 [110/3] via 10.12.13.12, 02:41:27, GigabitEthernet1
21.0.0.0/32 is subnetted, 1 subnets
O E2 21.21.21.21 [110/1] via 10.12.13.12, 02:16:38, GigabitEthernet1
23.0.0.0/32 is subnetted, 1 subnets
O E2 23.23.23.23 [110/1] via 10.12.13.12, 02:16:38, GigabitEthernet1
RR1#
RR1#show bgp vpnv4 unicast all summary | beg Neighbor
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
11.11.11.11 4 1 182 194 21 0 0 02:41:31 4
23.23.23.23 4 2 154 155 21 0 0 02:05:32 4
RR1#
RR1#show bgp vpnv4 unicast all
BGP table version is 21, local router ID is 13.13.13.13
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
t secondary path, L long-lived-stale,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 1:1
*>i 172.16.1.0/30 11.11.11.11 0 100 0 ?
*> 172.16.2.0/30 21.21.21.21 0 2 ?
*>i 192.168.1.1/32 11.11.11.11 0 100 0 65101 i
*> 192.168.1.2/32 21.21.21.21 0 2 65102 i
Route Distinguisher: 1:2
*>i 172.16.1.4/30 11.11.11.11 0 100 0 ?
*> 172.16.2.4/30 21.21.21.21 0 2 ?
*>i 192.168.2.1/32 11.11.11.11 0 100 0 65201 i
*> 192.168.2.2/32 21.21.21.21 0 2 65202 i
RR1#
RR2
RR2#show ip route ospf | beg Gateway
Gateway of last resort is not set
11.0.0.0/32 is subnetted, 1 subnets
O E2 11.11.11.11 [110/1] via 20.22.23.22, 02:10:29, GigabitEthernet1
13.0.0.0/32 is subnetted, 1 subnets
O E2 13.13.13.13 [110/1] via 20.22.23.22, 02:10:29, GigabitEthernet1
20.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
O 20.21.22.0/24 [110/2] via 20.22.23.22, 02:42:38, GigabitEthernet1
O 20.22.24.0/24 [110/2] via 20.22.23.22, 02:42:38, GigabitEthernet1
21.0.0.0/32 is subnetted, 1 subnets
O 21.21.21.21 [110/3] via 20.22.23.22, 02:42:38, GigabitEthernet1
22.0.0.0/32 is subnetted, 1 subnets
O 22.22.22.22 [110/2] via 20.22.23.22, 02:42:38, GigabitEthernet1
24.0.0.0/32 is subnetted, 1 subnets
O 24.24.24.24 [110/3] via 20.22.23.22, 02:42:37, GigabitEthernet1
RR2#show bgp vpnv4 unicast all summary | beg Neighbor
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
13.13.13.13 4 1 156 155 21 0 0 02:06:58 4
21.21.21.21 4 2 186 197 21 0 0 02:42:51 4
RR2#show bgp vpnv4 unicast all
BGP table version is 21, local router ID is 23.23.23.23
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
t secondary path, L long-lived-stale,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 1:1
*> 172.16.1.0/30 11.11.11.11 0 1 ?
*>i 172.16.2.0/30 21.21.21.21 0 100 0 ?
*> 192.168.1.1/32 11.11.11.11 0 1 65101 i
*>i 192.168.1.2/32 21.21.21.21 0 100 0 65102 i
Route Distinguisher: 1:2
*> 172.16.1.4/30 11.11.11.11 0 1 ?
*>i 172.16.2.4/30 21.21.21.21 0 100 0 ?
*> 192.168.2.1/32 11.11.11.11 0 1 65201 i
*>i 192.168.2.2/32 21.21.21.21 0 100 0 65202 i
RR2#
PE1
PE1#show bgp vpnv4 unicast all
BGP table version is 29, local router ID is 11.11.11.11
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
t secondary path, L long-lived-stale,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 1:1 (default for vrf A)
*> 172.16.1.0/30 0.0.0.0 0 32768 ?
*>i 172.16.2.0/30 21.21.21.21 0 100 0 2 ?
*> 192.168.1.1/32 172.16.1.2 0 0 65101 i
*>i 192.168.1.2/32 21.21.21.21 0 100 0 2 65102 i
Route Distinguisher: 1:2 (default for vrf B)
*> 172.16.1.4/30 0.0.0.0 0 32768 ?
*>i 172.16.2.4/30 21.21.21.21 0 100 0 2 ?
*> 192.168.2.1/32 172.16.1.6 0 0 65201 i
*>i 192.168.2.2/32 21.21.21.21 0 100 0 2 65202 i
PE1#
PE1#show bgp vpnv4 unicast all 192.168.1.2/32
BGP routing table entry for 1:1:192.168.1.2/32, version 27
Paths: (1 available, best #1, table A)
Flag: 0x100
Advertised to update-groups:
3
Refresh Epoch 1
2 65102
21.21.21.21 (metric 1) (via default) from 13.13.13.13 (13.13.13.13)
Origin IGP, metric 0, localpref 100, valid, internal, best
Extended Community: RT:1:1
mpls labels in/out nolabel/22
rx pathid: 0, tx pathid: 0x0
Updated on Oct 13 2022 01:41:45 UTC
PE1#show bgp vpnv4 unicast all 192.168.2.2/32
BGP routing table entry for 1:2:192.168.2.2/32, version 29
Paths: (1 available, best #1, table B)
Flag: 0x100
Advertised to update-groups:
1
Refresh Epoch 1
2 65202
21.21.21.21 (metric 1) (via default) from 13.13.13.13 (13.13.13.13)
Origin IGP, metric 0, localpref 100, valid, internal, best
Extended Community: RT:1:2
mpls labels in/out nolabel/24
rx pathid: 0, tx pathid: 0x0
Updated on Oct 13 2022 01:41:45 UTC
PE1#show ip route vrf A bgp
Routing Table: A
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, m - OMP
n - NAT, Ni - NAT inside, No - NAT outside, Nd - NAT DIA
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
H - NHRP, G - NHRP registered, g - NHRP registration summary
o - ODR, P - periodic downloaded static route, l - LISP
a - application route
+ - replicated route, % - next hop override, p - overrides from PfR
& - replicated local route overrides by connected
Gateway of last resort is not set
172.16.0.0/16 is variably subnetted, 3 subnets, 2 masks
B 172.16.2.0/30 [200/0] via 21.21.21.21, 03:26:17
192.168.1.0/32 is subnetted, 2 subnets
B 192.168.1.1 [20/0] via 172.16.1.2, 04:52:06
B 192.168.1.2 [200/0] via 21.21.21.21, 03:26:17
PE1#
PE1#
PE1#show ip route vrf B bgp
Routing Table: B
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, m - OMP
n - NAT, Ni - NAT inside, No - NAT outside, Nd - NAT DIA
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
H - NHRP, G - NHRP registered, g - NHRP registration summary
o - ODR, P - periodic downloaded static route, l - LISP
a - application route
+ - replicated route, % - next hop override, p - overrides from PfR
& - replicated local route overrides by connected
Gateway of last resort is not set
172.16.0.0/16 is variably subnetted, 3 subnets, 2 masks
B 172.16.2.4/30 [200/0] via 21.21.21.21, 03:26:22
192.168.2.0/32 is subnetted, 2 subnets
B 192.168.2.1 [20/0] via 172.16.1.6, 04:52:11
B 192.168.2.2 [200/0] via 21.21.21.21, 03:26:22
PE1#
PE2
PE2#show bgp vpnv4 unicast all
BGP table version is 29, local router ID is 21.21.21.21
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
t secondary path, L long-lived-stale,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 1:1 (default for vrf A)
*>i 172.16.1.0/30 11.11.11.11 0 100 0 1 ?
*> 172.16.2.0/30 0.0.0.0 0 32768 ?
*>i 192.168.1.1/32 11.11.11.11 0 100 0 1 65101 i
*> 192.168.1.2/32 172.16.2.2 0 0 65102 i
Route Distinguisher: 1:2 (default for vrf B)
*>i 172.16.1.4/30 11.11.11.11 0 100 0 1 ?
*> 172.16.2.4/30 0.0.0.0 0 32768 ?
*>i 192.168.2.1/32 11.11.11.11 0 100 0 1 65201 i
*> 192.168.2.2/32 172.16.2.6 0 0 65202 i
PE2#
PE2#
PE2#show bgp vpnv4 unicast all 192.168.1.1/32
BGP routing table entry for 1:1:192.168.1.1/32, version 27
Paths: (1 available, best #1, table A)
Flag: 0x100
Advertised to update-groups:
2
Refresh Epoch 1
1 65101
11.11.11.11 (metric 1) (via default) from 23.23.23.23 (23.23.23.23)
Origin IGP, metric 0, localpref 100, valid, internal, best
Extended Community: RT:1:1
mpls labels in/out nolabel/22
rx pathid: 0, tx pathid: 0x0
Updated on Oct 13 2022 01:40:25 UTC
PE2#show bgp vpnv4 unicast all 192.168.2.1/32
BGP routing table entry for 1:2:192.168.2.1/32, version 29
Paths: (1 available, best #1, table B)
Flag: 0x100
Advertised to update-groups:
1
Refresh Epoch 1
1 65201
11.11.11.11 (metric 1) (via default) from 23.23.23.23 (23.23.23.23)
Origin IGP, metric 0, localpref 100, valid, internal, best
Extended Community: RT:1:2
mpls labels in/out nolabel/24
rx pathid: 0, tx pathid: 0x0
Updated on Oct 13 2022 01:40:25 UTC
PE2#
PE2#
PE2#show ip route vrf A bgp
Routing Table: A
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, m - OMP
n - NAT, Ni - NAT inside, No - NAT outside, Nd - NAT DIA
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
H - NHRP, G - NHRP registered, g - NHRP registration summary
o - ODR, P - periodic downloaded static route, l - LISP
a - application route
+ - replicated route, % - next hop override, p - overrides from PfR
& - replicated local route overrides by connected
Gateway of last resort is not set
172.16.0.0/16 is variably subnetted, 3 subnets, 2 masks
B 172.16.1.0/30 [200/0] via 11.11.11.11, 03:28:59
192.168.1.0/32 is subnetted, 2 subnets
B 192.168.1.1 [200/0] via 11.11.11.11, 03:28:59
B 192.168.1.2 [20/0] via 172.16.2.2, 04:53:32
PE2#
PE2#show ip route vrf B bgp
Routing Table: B
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, m - OMP
n - NAT, Ni - NAT inside, No - NAT outside, Nd - NAT DIA
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
H - NHRP, G - NHRP registered, g - NHRP registration summary
o - ODR, P - periodic downloaded static route, l - LISP
a - application route
+ - replicated route, % - next hop override, p - overrides from PfR
& - replicated local route overrides by connected
Gateway of last resort is not set
172.16.0.0/16 is variably subnetted, 3 subnets, 2 masks
B 172.16.1.4/30 [200/0] via 11.11.11.11, 03:29:03
192.168.2.0/32 is subnetted, 2 subnets
B 192.168.2.1 [200/0] via 11.11.11.11, 03:29:03
B 192.168.2.2 [20/0] via 172.16.2.6, 04:53:36
PE2#
P1
P1#show ip route ospf
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, m - OMP
n - NAT, Ni - NAT inside, No - NAT outside, Nd - NAT DIA
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
H - NHRP, G - NHRP registered, g - NHRP registration summary
o - ODR, P - periodic downloaded static route, l - LISP
a - application route
+ - replicated route, % - next hop override, p - overrides from PfR
& - replicated local route overrides by connected
Gateway of last resort is not set
11.0.0.0/32 is subnetted, 1 subnets
O 11.11.11.11 [110/2] via 10.11.12.11, 04:55:02, GigabitEthernet1
13.0.0.0/32 is subnetted, 1 subnets
O 13.13.13.13 [110/2] via 10.12.13.13, 04:55:04, GigabitEthernet2
14.0.0.0/32 is subnetted, 1 subnets
O 14.14.14.14 [110/2] via 10.12.14.14, 04:55:04, GigabitEthernet3
21.0.0.0/32 is subnetted, 1 subnets
O E2 21.21.21.21 [110/1] via 10.12.14.14, 04:30:14, GigabitEthernet3
23.0.0.0/32 is subnetted, 1 subnets
O E2 23.23.23.23 [110/1] via 10.12.14.14, 04:30:14, GigabitEthernet3
P1#
P2
P2#show ip route ospf
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, m - OMP
n - NAT, Ni - NAT inside, No - NAT outside, Nd - NAT DIA
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
H - NHRP, G - NHRP registered, g - NHRP registration summary
o - ODR, P - periodic downloaded static route, l - LISP
a - application route
+ - replicated route, % - next hop override, p - overrides from PfR
& - replicated local route overrides by connected
Gateway of last resort is not set
11.0.0.0/32 is subnetted, 1 subnets
O E2 11.11.11.11 [110/1] via 20.22.24.24, 04:23:41, GigabitEthernet3
13.0.0.0/32 is subnetted, 1 subnets
O E2 13.13.13.13 [110/1] via 20.22.24.24, 04:23:41, GigabitEthernet3
21.0.0.0/32 is subnetted, 1 subnets
O 21.21.21.21 [110/2] via 20.21.22.21, 04:55:50, GigabitEthernet1
23.0.0.0/32 is subnetted, 1 subnets
O 23.23.23.23 [110/2] via 20.22.23.23, 04:55:50, GigabitEthernet2
24.0.0.0/32 is subnetted, 1 subnets
O 24.24.24.24 [110/2] via 20.22.24.24, 04:55:47, GigabitEthernet3
P2#
PE1#show bgp vpnv4 unicast vrf A 192.168.1.2/32
BGP routing table entry for 1:1:192.168.1.2/32, version 27
Paths: (1 available, best #1, table A)
Flag: 0x100
Advertised to update-groups:
3
Refresh Epoch 1
2 65102
21.21.21.21 (metric 1) (via default) from 13.13.13.13 (13.13.13.13)
Origin IGP, metric 0, localpref 100, valid, internal, best
Extended Community: RT:1:1
mpls labels in/out nolabel/22
rx pathid: 0, tx pathid: 0x0
Updated on Oct 13 2022 01:41:45 UTC
PE1#
PE1#show ip route 21.21.21.21 255.255.255.255
Routing entry for 21.21.21.21/32
Known via "ospf 1", distance 110, metric 1
Tag 2, type extern 2, forward metric 2
Last update from 10.11.12.12 on GigabitEthernet1, 04:40:27 ago
Routing Descriptor Blocks:
* 10.11.12.12, from 14.14.14.14, 04:40:27 ago, via GigabitEthernet1
Route metric is 1, traffic share count is 1
Route tag 2
PE1#
PE1#show mpls ldp bindings 21.21.21.21 32
lib entry: 21.21.21.21/32, rev 16
local binding: label: 25
remote binding: lsr: 12.12.12.12:0, label: 19
PE1#
PE1#show mpls forwarding-table 21.21.21.21 32
Local Outgoing Prefix Bytes Label Outgoing Next Hop
Label Label or Tunnel Id Switched interface
25 19 21.21.21.21/32 0 Gi1 10.11.12.12
PE1#
PE1#show ip cef vrf A 192.168.1.2/32 detai
192.168.1.2/32, epoch 2, flags [rib defined all labels]
recursive via 21.21.21.21 label 22
nexthop 10.11.12.12 GigabitEthernet1 label 19-(local:25)
PE1#
P1
P1#show mpls forwarding-table labels 19
Local Outgoing Prefix Bytes Label Outgoing Next Hop
Label Label or Tunnel Id Switched interface
19 30 21.21.21.21/32 22422480 Gi3 10.12.14.14
P1#
ASBR1
ASBR1#show mpls forwarding-table labels 30
Local Outgoing Prefix Bytes Label Outgoing Next Hop
Label Label or Tunnel Id Switched interface
30 21 21.21.21.21/32 22423284 Gi2 172.16.0.2
ASBR1#
ASBR2
ASBR2#show mpls forwarding-table labels 21
Local Outgoing Prefix Bytes Label Outgoing Next Hop
Label Label or Tunnel Id Switched interface
21 18 21.21.21.21/32 22424088 Gi1 20.22.24.22
ASBR2#
P2
P2#show mpls forwarding-table labels 18
Local Outgoing Prefix Bytes Label Outgoing Next Hop
Label Label or Tunnel Id Switched interface
18 Pop Label 21.21.21.21/32 35471358 Gi1 20.21.22.21
P2#
PE2
PE2#show ip cef vrf A 192.168.1.2/32 detail
192.168.1.2/32, epoch 2, flags [rib only nolabel, rib defined all labels]
dflt local label info: other/22 [0x2]
recursive via 172.16.2.2
attached to GigabitEthernet2
PE2#
Summary
Loopback0s of local PEs and RRs are advertised by the ASBR to the remote AS with labels.
Loopback0s of the remote PEs are redistributed into local IGP by the ASBR.
VPNv4 peering is established between RRs.
Above is a EBGP multi-hop session. This needs to be configured explicitly using “ebgp-multihop”.
RR should not change next-hop of the VPNv4 prefixes advertised to the remote AS. This needs to be configured explicitly using “next-hop-unchanged”.
