SD-WAN (Viptela) DIA - Advertise 0.0.0.0/0 to Core

Hi Guys,

Getting to grips with SD-WAN and DIA. It seems from the design guide there are two use cases to implement DIA:

1. Via centralised data policy distributed out by vsmart
2. Via creating a 0.0.0.0/0 route to VPN0 at the service side VPN template

I would like to use the centeralised data policy method of DIA as this seems to offer more granularity thanks to the use of lists/match statements etc (allows me to match specific prefixes to allow DIA)

However my issue is this, I am peering the cEdge to my core switch with a eBGP handoff, there is no default route in the cEdge to advertise into the core switch, see below

UC03-cEdge1#show ip route vrf 10 Routing Table: 10 Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, m - OMP n - NAT, Ni - NAT inside, No - NAT outside, Nd - NAT DIA i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route H - NHRP, G - NHRP registered, g - NHRP registration summary o - ODR, P - periodic downloaded static route, l - LISP a - application route + - replicated route, % - next hop override, p - overrides from PfR & - replicated local route overrides by connected Gateway of last resort is not set 10.0.0.0/8 is variably subnetted, 9 subnets, 4 masks B 10.250.9.0/30 [20/0] via 10.250.9.6, 00:23:13 C 10.250.9.4/30 is directly connected, GigabitEthernet4.10 L 10.250.9.5/32 is directly connected, GigabitEthernet4.10 B 10.250.10.0/24 [20/0] via 10.250.9.6, 00:23:13 m 10.250.100.0/24 [251/0] via 2.2.2.1, 00:23:37, Sdwan-system-intf m 10.250.101.0/29 [251/0] via 2.2.2.1, 00:23:37, Sdwan-system-intf m 10.250.250.0/24 [251/0] via 2.2.2.1, 00:23:37, Sdwan-system-intf m 10.251.10.0/24 [251/0] via 4.4.4.2, 00:23:29, Sdwan-system-intf [251/0] via 4.4.4.1, 00:23:29, Sdwan-system-intf m 10.251.20.0/29 [251/0] via 4.4.4.2, 00:23:29, Sdwan-system-intf [251/0] via 4.4.4.1, 00:23:29, Sdwan-system-intf 

The DIA data policy is getting pushed to from vSmart as expected

UC03-cEdge1#show sdwan policy from-vsmart from-vsmart data-policy _corp_and_guest_DIA-BRANCH direction from-service vpn-list corp_and_guest sequence 1 match destination-data-prefix-list RFC-1918 action accept sequence 11 match source-data-prefix-list All-Traffic action accept nat use-vpn 0 no nat fallback default-action accept from-vsmart lists vpn-list corp_and_guest vpn 10 vpn 29 from-vsmart lists data-prefix-list All-Traffic ip-prefix 0.0.0.0/0 from-vsmart lists data-prefix-list RFC-1918 ip-prefix 10.0.0.0/8 ip-prefix 172.16.0.0/12 ip-prefix 192.168.0.0/16 

I can reach the internet directly from the cEdge's service side interface, however because this method of DIA policy does not create a default route in the routing table I cant advertise anything into my core switch to give the rest of the network DIA - I really don't want to create a static route on the core.

Without switching to the DIA nat route method at the template level, I am struggling to think how i could announce a default route to my core switch.

any ideas please?