Dell EMC Configuration Guide for the S4048T–ON System 9.14.2.4

In the above illustration, R1 and R2 are the VTEPs that are trying to form the VXLAN tunnel. R3, the route reflector, exchanges the routes across two IBGP peers (R1 and R2). Also, the R3 connects the R1 and R2 through a default route.

Following is the output of show ip routecommand for the above connection:

DellEMC# show ip route
Destination            Gateway                  Dist/Metric Last      Change
-----------            -----                    -----------           -----------
   
*B IN 0.0.0.0/0        via 192.168.11.2         200/0                16:13:30
 C    1.1.1.1/32       Direct, Lo 1               0/0                 8:59:34
 B IN 2.2.2.2/32       via 192.168.22.1         200/0                00:36:48

From the above routing table it is understood that the remote VTEP 2.2.2.2/32 is resolved through next-hop 192.168.22.1, which is not directly connected. This route is considered as a recursive route and there is no other route matching the next-hop except the default 0.0.0.0/0. If the recursive lookup ends in a default route, the route is considered to be an unsuccessful recursion. The VXLAN tunnel stays down even though the remote VTEP IP is reachable through a recursive route. As a workaround, make sure to advertise the underlying routes from the route-reflector, so that the recursive lookup succeeds.