OSPF work between NE40 and Cxxxxx.The interconnecting network-segment between NE40 and Cxxxxx is 192.168.1.1/30,the interface address of Cxxxxx is 192.168.1.2/30.On Cxxxxx, release one OSPF default route.At the OSPF procesion of NE40,import one static route 126.96.36.199/24,its nexthop is 10.1.1.1.As tracert 188.8.131.52，detect the packet oscillates between 192.168.1.1 and 192.168.1.2.
For the limitation of NE40,currently only the single interface vlan forwarding is supported.To solve the problem, we must avoid it via the networking solution.If we configure multiple VLAN-interfaces or underlying layer 2 LSW,make the local VLAN interface contain one physical interface only.
The reason is that the static route 184.108.40.206/24 is invalid,its nexthop 10.1.1.2 is the address of some layer 3 VLAN interface address on NE40，both the physical interface and VLANinterface are UP，but this VLAN interface contains three physical interfaces. If we want to do the routing forwarding via NE40 layer 2 boards, configure the Vlan to the routing mode via "property routing", but under this mode, each VLAN interface can contain one physical interface only. In this network, because we did not configure property routing, this VLAN cannot do the routing forwarding. So the packets accessing 220.127.116.11/24 can match the default routes on NE40 only，the packets are forwarded to Cxxxxx， while on Cxxxxx,we learn the O_ASE routes of 18.104.22.168 via OSPF, the nexthop of O_ASE is 192.168.1.1,it backs to NE40, loops form.