The second OSPF connectivity option is to place the PE-to-CE link into a non-backbone area. In this case, the PE-router acts as an ABR (and an ASBR) for the customer site, and forms an adjacency with the CE-router so that it can exchange LSAs. An illustration of this connectivity option can be seen in Figure 10-7.
Figure 10-7 shows that the FastFoods San Jose CE-router has an adjacency with the SuperCom San Jose PE-router in OSPF area 1. The Type-1 LSA describing the 126.96.36.199/32 prefix is received by the SuperCom San Jose PE-router and is placed into the FastFoods VRF. This LSA can be seen in Example 10-12.
San Jose# show ip ospf data router 188.8.131.52 OSPF Router with ID (184.108.40.206) (Process ID 100) Router Link States (Area 1) LS age: 1707 Options: (No TOS-capability, DC) LS Type: Router Links Link State ID: 220.127.116.11 Advertising Router: 18.104.22.168 LS Seq Number: 80000002 Checksum: 0xE118 Length: 48 Number of Links: 2 Link connected to: a Stub Network (Link ID) Network/subnet number: 22.214.171.124 (Link Data) Network Mask: 255.255.255.255 Number of TOS metrics: 0 TOS 0 Metrics: 1 Link connected to: a Transit Network (Link ID) Designated Router address: 126.96.36.199 (Link Data) Router Interface address: 188.8.131.52 Number of TOS metrics: 0 TOS 0 Metrics: 1
This route is then redistributed into MP-iBGP and is advertised across the MPLS/VPN backbone as an intra-area route. This is highlighted by the OSPF route type of 1:2:0 shown in Example 10-13, where the 1 signifies that the route belongs to OSPF area 1, and the 2 signifies that the route type is intra-area.
San Jose# show ip route vrf FastFoods 184.108.40.206 Routing entry for 220.127.116.11/32 Known via "ospf 100", distance 110, metric 2, type intra area Redistributing via bgp 1, ospf 100 Advertised by bgp 1 match internal external 1 & 2 Last update from 18.104.22.168 on FastEthernet0/0, 00:30:59 ago Routing Descriptor Blocks: * 22.214.171.124, from 126.96.36.199, 00:30:59 ago, via FastEthernet0/0 Route metric is 2, traffic share count is 1 San Jose# show ip bgp vpnv4 vrf FastFoods 188.8.131.52 BGP routing table entry for 1:26:184.108.40.206/32, version 102 Paths: (1 available, best #1, table FastFoods) Advertised to non peer-group peers: 220.127.116.11 Local 18.104.22.168 from 0.0.0.0 (22.214.171.124) Origin incomplete, metric 2, localpref 100, weight 32768, valid, sourced, best Extended Community: RT:100:26 OSPF RT:1:2:0
When the route is received by the SuperCom Paris PE-router and is imported into the FastFoods VRF, a summary LSA for the route is advertised into the FastFoods site in Lyon. This summary LSA can be seen in Example 10-14.
Paris# show ip ospf data summary 126.96.36.199 OSPF Router with ID (188.8.131.52) (Process ID 100) Summary Net Link States (Area 1) LS age: 1533 Options: (No TOS-capability, DC, Downward) LS Type: Summary Links(Network) Link State ID: 184.108.40.206 (summary Network Number) Advertising Router: 220.127.116.11 LS Seq Number: 80000001 Checksum: 0xED1F Length: 28 Network Mask: /32 TOS: 0 Metric: 2