Interface-ful IP-VRF-to-IP-VRF with unnumbered SBD IRB model

Interface-ful refers to the fact that there is a full IRB interface between the VPRN and the SBD. However, the SBD IRB is unnumbered in this model, which means no IP address is configured on it. In SR OS, an unnumbered SBD IRB is equivalent to an R-VPLS linked to a VPRN interface through an EVPN tunnel. See EVPN for VXLAN in EVPN tunnel R-VPLS services for more information.

Figure 1 illustrates this model.

Figure 1. Interface-ful IP-VRF-to-IP-VRF with unnumbered SBD IRB model

Figure 1 shows a 7750 SR and a third-party router running interface-ful IP-VRF-to-IP-VRF with unnumbered SBD IRB model. The IP prefix routes are now expected to have a zero gateway IP and the MAC in the router's MAC extended community used for the recursive resolution to a MAC/IP route.

The corresponding configuration of the 7750 SR VPRN and SBD in the example could be:

7750SR#config>service#

vpls 2 customer 1 name "sbd" create
 allow-ip-int-bind
 exit
 bgp
 exit
 bgp-evpn
evi 2
ip-route-advertisement
mpls bgp 1
auto-bind-tunnel resolution any
no shutdown

vprn 1 customer 1 create
 route-distinguisher auto-rd
 interface "sbd" create
  ipv6
  exit
 vpls "sbd" 
  evpn-tunnel ipv6-gateway-address mac

Note that the evpn-tunnel command controls the use of the Router's MAC extended community and the zero gateway IP in the IPv4-prefix route. For IPv6, the ipv6-gateway-address mac option makes the router advertise the IPv6-prefix routes with a Router's MAC extended community and zero gateway IP.