Sham-link is down

[sachin30720041]

Hello,

I have following setup. And I have configured sham link between 2 PEs. But sham-link does not come up. I am not sure what configuration am I missing ?

ios11---------CSR1(PE)---------CSR2----------CSR3(PE)-------ios22

When I execute "show ip ospf sham-link" on CSR1 and CSR2 I see sham-link is down.

CSR1#show ip ospf sham-links
Sham Link OSPF_SL0 to address 222.222.222.222 is down
Area 0 source address 111.111.111.111
Run as demand circuit
DoNotAge LSA allowed. Cost of using 1 State DOWN

CSR3#show ip ospf sham-links
Sham Link OSPF_SL0 to address 111.111.111.111 is down
Area 0 source address 222.222.222.222
Run as demand circuit
DoNotAge LSA allowed. Cost of using 1 State DOWN,

ios11
--------------
int gi0/2
ip address 100.10.10.11 255.255.255.0
ip ospf 1 area 0
no sh

int lo0
ip address 11.11.11.11 255.255.255.255
ip ospf 1 area 0
exit

router ospf 1
exit

CSR1
-------------------
vrf def vrf1
rd 1:1
address-family ipv4 unicast
route-target export 1:1
route-target import 3:3
exit

int gi2
vrf forw vrf1
ip address 100.10.10.1 255.255.255.0
ip ospf 11 area 0
no sh

router ospf 11 vrf vrf1
area 0 sham-link 111.111.111.111 222.222.222.222
exit

int gi1
ip address 100.10.20.1 255.255.255.0
ip ospf 1 area 0
no sh

int lo0
ip address 1.1.1.1 255.255.255.255
ip ospf 1 area 0
exit

int lo1
vrf forw vrf1
ip address 111.111.111.111 255.255.255.255
exit

router ospf 1
mpls ldp autoconfig
exit

router bgp 13
template peer-session session1
remote-as 13
update-source lo0
exit
neighbor 3.3.3.3 inherit peer-session session1
address-family vpnv4 unicast
neighbor 3.3.3.3 activate
exit
address-family ipv4 vrf vrf1
network 111.111.111.111 mask 255.255.255.255
exit

CSR2
------------------------
int gi2
ip address 100.20.30.2 255.255.255.0
ip ospf 1 area 0
no sh

int gi1
ip address 100.10.20.2 255.255.255.0
ip ospf 1 area 0
no sh

int lo0
ip address 2.2.2.2 255.255.255.255
ip ospf 1 area 0
exit

router ospf 1
mpls ldp autoconfig
exit

CSR3
-------------------
vrf def vrf1
rd 3:3
address-family ipv4 unicast
route-target export 3:3
route-target import 1:1
exit

int gi1
vrf forw vrf1
ip address 100.20.20.3 255.255.255.0
ip ospf 11 area 0
no sh

router ospf 11 vrf vrf1
area 0 sham-link 222.222.222.222 111.111.111.111
exit

int gi2
ip address 100.20.30.3 255.255.255.0
ip ospf 1 area 0
no sh

int lo0
ip address 3.3.3.3 255.255.255.255
ip ospf 1 area 0
exit

int lo1
vrf for vrf1
ip address 222.222.222.222 255.255.255.255
exit

router ospf 1
mpls ldp autoconfig
exit

router bgp 13
template peer-session session1
remote-as 13
update-source lo0
exit
neighbor 1.1.1.1 inherit peer-session session1
address-family vpnv4 unicast
neighbor 1.1.1.1 activate
exit
address-family ipv4 vrf vrf1
network 222.222.222.222 mask 255.255.255.255
exit

ios22
---------------------------
int gi0/1
ip address 100.20.20.22 255.255.255.0
ip ospf 1 area 0
no sh

int lo0
ip address 22.22.22.22 255.255.255.255
ip ospf 1 area 0
exit

router ospf 1
exit

Thanks,

Sachin

[MHM Cisco World]

I check your config, 
all your config is OK except 
you not redistribute the OSPF 11 vrf into BGP 13
and you not redistribute BGP 13 into OSPF 11 vrf
that it.

[MHM Cisco World]

for typo bgp 100 (I correct it)
I usually use in my MPLS LAB BGP AS number same as OSPF process and always I use 100.

[sachin30720041 · Accepted solution]

It seems area 0 can not have sham link. Below is the complete configuration.

ios11
--------------
int gi0/2
ip address 100.10.10.11 255.255.255.0
ip ospf 1 area 1
no sh

int lo0
ip address 11.11.11.11 255.255.255.255
ip ospf 1 area 1
exit

router ospf 1
exit

CSR1
-------------------
vrf def vrf1
rd 1:1
address-family ipv4 unicast
route-target export 1:1
route-target import 3:3
exit

int gi2
vrf forw vrf1
ip address 100.10.10.1 255.255.255.0
ip ospf 11 area 1
no sh

router ospf 11 vrf vrf1
redistribute bgp 13
area 1 sham-link 111.111.111.111 222.222.222.222
exit

int gi1
ip address 100.10.20.1 255.255.255.0
ip ospf 1 area 0
no sh

int lo0
ip address 1.1.1.1 255.255.255.255
ip ospf 1 area 0
exit

int lo1
vrf forw vrf1
ip address 111.111.111.111 255.255.255.255
exit

router ospf 1
mpls ldp autoconfig
exit

router bgp 13
template peer-session session1
remote-as 13
update-source lo0
exit
neighbor 3.3.3.3 inherit peer-session session1
address-family vpnv4 unicast
neighbor 3.3.3.3 activate
exit
address-family ipv4 vrf vrf1
redistribute ospf 11
network 111.111.111.111 mask 255.255.255.255
exit

CSR2
------------------------
int gi2
ip address 100.20.30.2 255.255.255.0
ip ospf 1 area 0
no sh

int gi1
ip address 100.10.20.2 255.255.255.0
ip ospf 1 area 0
no sh

int lo0
ip address 2.2.2.2 255.255.255.255
ip ospf 1 area 0
exit

router ospf 1
mpls ldp autoconfig
exit

CSR3
-------------------
vrf def vrf1
rd 3:3
address-family ipv4 unicast
route-target export 3:3
route-target import 1:1
exit

int gi1
vrf forw vrf1
ip address 100.20.20.3 255.255.255.0
ip ospf 11 area 1
no sh

router ospf 11 vrf vrf1
redistribute bgp 13
area 1 sham-link 222.222.222.222 111.111.111.111
exit

int gi2
ip address 100.20.30.3 255.255.255.0
ip ospf 1 area 0
no sh

int lo0
ip address 3.3.3.3 255.255.255.255
ip ospf 1 area 0
exit

int lo1
vrf for vrf1
ip address 222.222.222.222 255.255.255.255
exit

router ospf 1
mpls ldp autoconfig
exit

router bgp 13
template peer-session session1
remote-as 13
update-source lo0
exit
neighbor 1.1.1.1 inherit peer-session session1
address-family vpnv4 unicast
neighbor 1.1.1.1 activate
exit
address-family ipv4 vrf vrf1
redistribute ospf 11
network 222.222.222.222 mask 255.255.255.255
exit

ios22
---------------------------
int gi0/1
ip address 100.20.20.22 255.255.255.0
ip ospf 1 area 1
no sh

int lo0
ip address 22.22.22.22 255.255.255.255
ip ospf 1 area 1
exit

router ospf 1
exit

[MHM Cisco World]

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