MPLS Layer 3 VPNs
- Routing protocol between PE and CE to learn customer routes
- VRF - Virtual Routing and Forwarding
- VPNv4 Route - Information added to routes to identify the customer
- mBGP used to exchange VPNv4 routes between PE routers
- No encryption on traffic
PE to PE mBGP
router bgp 65536
neighbor 5.5.5.5 remote-as 65536
neighbor 5.5.5.5 update-source Loopback0
address-family vpnv4
neighbor 5.5.5.5 activate
neighbor 5.5.5.5 send-community extended
show ip bgp neighbors | section capabilities
VRFs

Export - take route out of VRF
Import - adding route into VRF
VRF is locally significant, case sensitive
Route Distinguisher/Targets ASN:# or IP:#. can be the same at both sides
Export on one side needs to match Import on other side
Interface will lose IP address configuration when assigning a vrf
!!IPv4 only
ip vrf 101:ACME
vrf definition 101:ACME
rd 1.1.1.1:1
address-family ipv4
route-target export 1.1.1.1:101
route-target import 5.5.5.5:101
int fa2/0
vrf forwarding 101:ACME
ip address 172.16.101.1 255.255.255.252
show vrf
show ip route vrf 101:ACME
CE to PE routing
Don’t need to use the same protocol at each site.
next hop self option needed if using BGP
!!PE
router ospf 101 vrf 101:ACME
network 172.16.101.1 0.0.0.0 area 0
router eigrp 1
address-family ipv4 vrf 101:ACME autonomous-system 101
network 172.16.0.0
router rip
version 2
address-family ipv4 vrf 101:ACME
network 192.168.202.0
no auto-summary
router bgp 65536
address-family ipv4 vrf 101:ACME
neighbor 192.168.202.2 remote-as 65537
address-family vpnv4
neighbor 1.1.1.1 next-hop-self
!!CE
router ospf 1
net 0.0.0.0 255.255.255.255 area 0
router eigrp 101
no auto-summary
network 0.0.0.0
router rip
version 2
network 0.0.0.0
no auto-summary
router bgp 65537
neighbor 192.168.202.1 remote-as 65536
redistribute connected
Redistribution
Not needed if using BGP
VPNv4 Routes - Prefix, RD, RT, VPN Label
show ip bgp vpnv4 rd 1.1.1.1:1 labels
OR show bgp vpnv4 unicast rd 1.1.1.1:1 labels
show mpls forwarding-table vrf 101:ACME
router bgp 65536
address-family ipv4 vrf 101:ACME
redistribute ospf 101 vrf 101:ACME
redistribute eigrp 101 vrf 101:ACME
redistribute rip
router ospf 101 vrf 101:ACME
redistribute bgp 65536 subnets
router eigrp 1
address-family ipv4 vrf 101:ACME autonomous-system 101
redistribute bgp 65536 metric 1 1 1 1 1
router rip
version 2
address-family ipv4 vrf 101:ACME
redistribute bgp 65536 metric 5