ā06-16-2022 07:09 PM
Hello,
XRV1 and XRv2 are the PE routers. And ios1 and ios4 are the CE routers
ios1-----XRv1----XRV2----ios4
I have configured sham link between xrv1 and xrv2. Sham-link is up. 4.4.4.4/32 is a loopback on ios4.
On ios1, 4.4.4.4/32 is received as O*IA route. because of sham link I am expecting (4.4.4.4/32) to be intra-area route.
Am I missing any configuration?
Below is the configuration of all the routers.
ios1
--------------
int gi0/0
ip address 100.10.20.1 255.255.255.0
ip ospf 1 area 0
no sh
int lo0
ip ospf 1 area 0
ip address 1.1.1.1 255.255.255.255
router ospf 1
router-id 1.1.1.1
prefix-suppression
XRV1
-------------------------------
vrf vrf1
address-family ipv4 unicast
export route-target 2:2
import route-target 3:3
exit
int gi0/0/0/0
vrf vrf1
ip address 100.10.20.2 255.255.255.0
no sh
int gi0/0/0/1
ip address 100.20.30.2 255.255.255.0
no sh
int lo0
ip address 2.2.2.2 255.255.255.255
int lo1
vrf vrf1
ip address 22.22.22.22 255.255.255.255
router ospf 1
router-id 2.2.2.2
area 0
int gi0/0/0/1
int lo0
vrf vrf1
domain-id type 0005 value AAAAAAAAAAAA
redistribute bgp 23
area 0
sham-link 22.22.22.22 33.33.33.33
int gi0/0/0/0
router bgp 23
address-family ipv4 unicast
exit
address-family vpnv4 unicast
exit
session-group session1
remote-as 23
update-source lo0
exit
neighbor 3.3.3.3
use session-group session1
address-family vpnv4 unicast
exit
vrf vrf1
rd 2:2
address-family ipv4 unicast
network 22.22.22.22/32
redistribute ospf 1
exit
XRV2
------------------------------
int lo1
vrf vrf1
ip address 33.33.33.33 255.255.255.255
exit
vrf vrf1
address-family ipv4 unicast
export route-target 3:3
import route-target 2:2
exit
int gi0/0/0/1
ip address 100.20.30.3 255.255.255.0
no sh
int lo0
ip address 3.3.3.3 255.255.255.255
int gi0/0/0/0
vrf vrf1
ip address 100.30.40.3 255.255.255.0
no sh
router ospf 1
area 0
int gi0/0/0/1
int lo0
vrf vrf1
domain-id type 0005 value AAAAAAAAAAAA
redistribute bgp 23
area 0
sham-link 33.33.33.33 22.22.22.22
int gi0/0/0/0
router bgp 23
address-family vpnv4 unicast
exit
address-family ipv4 unicast
exit
session-group session1
remote-as 23
update-source lo0
exit
neighbor 2.2.2.2
use session-group session1
address-family vpnv4 unicast
exit
vrf vrf1
rd 3:3
address-family ipv4 unicast
network 33.33.33.33/32
redistribute ospf 1
exit
router ospf 1
router-id 3.3.3.3
prefix-suppression
ios4
------------------
int gi0/0
ip address 100.30.40.4 255.255.255.0
ip ospf 1 area 0
no sh
int lo0
ip address 4.4.4.4 255.255.255.255
ip ospf 1 area 0
router ospf 1
prefix-suppression
ā06-17-2022 01:02 AM
ā06-18-2022 09:47 AM - edited ā06-18-2022 10:27 AM
I have removed redistribute command under bgp but I have to keep 'redistribute bgp 23' under ospf. If I remove 'redistribute bgp 23' under ospf then sham link goes down. Why do we need ''redistribute bgp 23' under ospf ? If I use Cisco XE instead of XRV, then removing 'redistribute bgp 23' under ospf configuration does not impact sham link. Sham link stays up.
router ospf 1
router-id 3.3.3.3
prefix-suppression
area 0
mpls ldp auto-config
interface Loopback0
!
interface GigabitEthernet0/0/0/1
!
!
vrf vrf1
domain-id type 0005 value AAAAAAAAAAAA
redistribute bgp 23
area 0
interface GigabitEthernet0/0/0/0
ā06-17-2022 02:44 AM - edited ā06-17-2022 02:48 AM
try do the following :-
CE-PE-PE-CE
*between PE run OSPF 1 with area 0 in global mode not in VRF
**between PE CE run OSPF 10 with area 0, OSPF 10 is in VRF mode and redistribute it under the BGP IPv4 VRF.
***advertise the LO of sham under the BGP IPv4 VRF.
****config the sham under the OSPF 10 VRF.
ā06-18-2022 10:52 AM
https://ipwithease.com/understand-configure-ospf-sham-links/
check this link,
as I mention above you have only one OSPF process for both MPLS Core and CE-PE ? you need two
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