Carrier Support Carrier (CSC) Notes
\ Carrier Support Carrier (CSC)
ISP1
– Main ISP
-> Core ISP
ISP2
– Second level ISP
-> Tier 2 ISP
Clients
– Connected to ISP2
1. ISP1 provides L3VPN connection to ISP2
2. Because of this connection, ISP2 PE routers can ping each other loopback to loopback
3. VPNv4 neighbors between ISP2 PE routers require end-to-end Labeled Switch Path (LSP)
4. The LSP is missing on VRF links of ISP1
-> CSC-PE to CSC-CE
5. To activate LSP, there are two options
– If CSC-PE to CSC-CE protocol is IGP
-> IGP + label
– If CSC-PE to CSC-CE protocol is eBGP
-> eBGP + label
6. For VRF interfaces, if LSP is required, then the only option on XR routers is eBGP
Configuring CSC
1. Configure ISP1 with L3VPN
2. Enable communication between ISP2 PE routers
3. Configure “label processing” between ISP1 and ISP2
4. Configure L3VPN between ISP2 PE routers
5. Enable communication between client routers by CSC-CE to CE configuration
6. In case ISP1 and ISP2 has XR routers, then two things to remember
– Static route is needed for next-hop IP address between ASBRs
– Only eBGP supported as VRF + label protocol
! R1
router rip
version 2
network 1.0.0.0
! R2
router bgp 200
address-family ipv4 unicast
network 2.2.2.2/32
allocate-label all
neighbor 23.0.0.3
remote-as 100
address-family ipv4 labeled-unicast
route-policy allow-all in
route-policy allow-all out
route-policy allow-all
pass
end
router static
address-family ipv4 unicast
23.0.0.3/32 gi0/0/0/1
!
router bgp 200
address-family vpnv4 unicast
neighbor 7.7.7.7
remote-as 200
update-source lo0
address-family vpnv4 unicast
!
vrf DEF
address-family ipv4 unicast
export route-target 2:2
import route-target 2:2
router bgp 200
vrf DEF
rd 2:2
int gi0/0/0/0
no ipv4 address 12.0.0.2 255.255.255.0
vrf DEF
ipv4 address 12.0.0.2 255.255.255.0
!
router rip
vrf DEF
int gi0/0/0/0
redistribute bgp 200
router bgp 200
vrf DEF
address-family ipv4 unicast
redistribute rip
! R3
mpls ldp
router ospf 1
router-id 3.3.3.3
mpls ldp auto-config
area 0
int lo0
int gi0/0/0/1
!
vrf ABC
address-family ipv4 unicast
export route-target 1:1
import route-target 1:1
router bgp 100
bgp router-id 3.3.3.3
vrf ABC
rd 1:1
int gi0/0/0/0
no ipv4 address 23.0.0.3 255.255.255.0
vrf ABC
ipv4 address 23.0.0.3 255.255.255.0
!
router bgp 100
address-family vpnv4 unicast
vrf ABC
address-family ipv4 unicast
redistribute connected
allocate-label all
neighbor 23.0.0.2
remote-as 200
address-family ipv4 labeled-unicast
route-policy allow-all in
route-policy allow-all out
as-override
route-policy allow-all
pass
end
router static
vrf ABC
address-family ipv4 unicast
23.0.0.2/32 gi0/0/0/1
!
router bgp 100
neighbor 6.6.6.6
remote-as 100
update-source lo0
address-family vpnv4 unicast
! R4
mpls ldp
router ospf 1
router-id 4.4.4.4
mpls ldp auto-config
area 0
int lo0
int gi0/0/0/0
int gi0/0/0/1
! R5
mpls label protocol ldp
mpls ldp router-id lo0 force
int lo0
ip ospf 1 area 0
int e1/0
ip ospf 1 area 0
int e1/1
ip ospf 1 area 0
router ospf 1
router-id 5.5.5.5
mpls ldp autoconfig
! R6
mpls label protocol ldp
mpls ldp router-id lo0 force
int lo0
ip ospf 1 area 0
int e1/0
ip ospf 1 area 0
router ospf 1
router-id 6.6.6.6
mpls ldp autoconfig
!
vrf definition ABC
rd 1:1
address-family ipv4
route-target both 1:1
int e1/1
vrf forwarding ABC
ip address 67.0.0.6 255.255.255.0
!
router bgp 100
bgp router-id 6.6.6.6
no bgp default ipv4-unicast
address-family ipv4 vrf ABC
neighbor 67.0.0.7 remote-as 200
neighbor 67.0.0.7 activate
neighbor 67.0.0.7 as-override
neighbor 67.0.0.7 send-label
redistribute connected
!
router bgp 100
neighbor 3.3.3.3 remote-as 100
neighbor 3.3.3.3 update-source lo0
address-family vpnv4
neighbor 3.3.3.3 activate
neighbor 3.3.3.3 send-community extended
! R7
router bgp 200
address-family ipv4 unicast
network 7.7.7.7/32
allocate-label all
neighbor 67.0.0.6
remote-as 100
address-family ipv4 labeled-unicast
route-policy allow-all in
route-policy allow-all out
route-policy allow-all
pass
end
router static
address-family ipv4 unicast
67.0.0.6/32 gi0/0/0/1
!
router bgp 200
address-family vpnv4 unicast
neighbor 2.2.2.2
remote-as 200
update-source lo0
address-family vpnv4 unicast
!
vrf DEF
address-family ipv4 unicast
export route-target 2:2
import route-target 2:2
router bgp 200
vrf DEF
rd 2:2
int gi0/0/0/0
no ipv4 address 78.0.0.7 255.255.255.0
vrf DEF
ipv4 address 78.0.0.7 255.255.255.0
!
router rip
vrf DEF
int gi0/0/0/0
redistribute bgp 200
router bgp 200
vrf DEF
address-family ipv4 unicast
redistribute rip
! R8
router rip
version 2
network 78.0.0.0
network 8.0.0.0
Verification:
! R1
sh rip database
sh ip route rip
ping 8.8.8.8
! R2
sh bgp ipv4 labeled-unicast sum
sh bgp ipv4 labeled-unicast
sh route bgp
sh route static
ping 7.7.7.7
sh bgp vpnv4 u sum
sh bgp vpnv4 u
sh vrf DEF detail
sh rip vrf DEF database
! R3
sh ospf int bri
sh ospf nei
sh route ospf
sh mpls int
sh mpls ldp nei bri
sh mpls ldp dis
sh vrf ABC detail
sh bgp vrf ABC ipv4 labeled-unicast sum
sh bgp vrf ABC ipv4 labeled-unicast
sh route vrf ABC static
sh bgp vpnv4 u sum
sh bgp vpnv4 u
sh route vrf ABC bgp
sh mpls forwarding
! R4
sh ospf int bri
sh ospf nei
sh route ospf
sh mpls int
sh mpls ldp nei bri
sh mpls ldp dis
! R5
sh ip ospf int bri
sh ip ospf nei
sh ip route ospf
sh mpls int
sh mpls ldp nei
sh mpls ldp dis
! R6
sh ip ospf int bri
sh ip ospf nei
sh ip route ospf
sh mpls int
sh mpls ldp nei
sh mpls ldp dis
sh vrf detail
sh bgp vrf ABC all sum
sh bgp vrf ABC all
sh bgp vpnv4 u all sum
sh bgp vpnv4 u all
sh mpls forwarding
! R7
sh bgp ipv4 labeled-unicast sum
sh bgp ipv4 labeled-unicast
sh route bgp
sh route static
ping 2.2.2.2
sh bgp vpnv4 u sum
sh bgp vpnv4 u
sh vrf DEF detail
sh rip vrf DEF database
! R8
sh rip database
sh ip route rip
ping 1.1.1.1
