This lab showcases a Carrier Supporting Carrier setup.
It shows a Customer with two sites connected to ISP1 who in turn, has two disparate areas connected via a Backbone Provider implementing CsC.
Customer A has two sites connected to ISP1 in a VRF called CUST_1.
The following are the primary features of this CsC design:
- IS-IS and LDP is used throughout ISP1.
- ISP1 has one route reflector in each area running VPNv4 to the PE routers, and between each other.
- The connection between ASBR1 and BB-PE1 is running OSPF and LDP.
- The loopbacks of RR1 and PE1 are redistributed from IS-IS into OSPF and sent to BB-PE1.
- ASBR1 also redistributes from OSPF into IS-IS (this is expected to be loopbacks for RR2 and PE2).
- The connection between ASBR2 and BB-PE2 is running BGP-LU.
- The loopbacks for RR2 and PE2 are advertised to BB-PE2.
- Instead of redistributing into the local IGP, ASRB1 runs BGP-LU to RR2 who in turn runs BGP-LU to PE2 into order to communicate the label for PE1.
- The customer subnets are represented by loopbacks on the CE routers.
For full details on how CsC works check out this document.
> GNS3: 13 x 3725s
> EVE-NG: 13 x IOS-XE 16.6.5s