NE80E-2 cannot ping to the network segment (attached with MA5200) with direct interface under NE40-2.
1. ISIS is enabled between four GSRs and NE80E.
2. Between NE80E and NE40, and between two NE40s, OSPF is enabled.
3. Import the OSPF route into the ISIS area of NE80E-1, and the direct route into OSPF of NE40-2.
1. At NE80E-2, execute trace command for MA5200, with two next hops pointting to GSR-2 and NE80E-1 Check the routing table, and the route learned through ISIS has a priority of 15.
2. Check the OSPF LSDB at NE80E-2, and we could find that the ASE route of the network segment is learned from NE40-2, with priority as 150.
3. At NE40-2, use network command to enable the direct network segment; the next hop of the route of the network segment learned at NE80E-2 points to NE40- 2, and the network segment could be pinged through.
The case involves the import between dynamic routing protocols, so it may relate to the priority of protocol. Once NE40-2 imports the direct network segment, the route is learned by OSPF of NE80E-1, and then into ISIS, with priority as 150. The route that NE80E-1 has advertised to both NE80E-2 and GSR has the priority of 15, so NE80E-2 points the next hop of the route for direct interface of NE40 to NE80E-1 and GSR-2.
1. It would better to deploy one dynamic IGP protocol in AS.
2. In OSPF, it'd better to use network command, and avoid import direct command.
3. If necessary to deploy multiple routing protocols, it would better to define the priority for the protocols as to avoid loopback.