Two NE80E form core network in one MAN. One ISN8850 dual-homes to two NE80E and OSPF is enabled on three devices (in area 0).
Before NE80E upgrades, ISN8850 can learn two default routes advertised by two NE80E and forms load balancing.
After one NE80E upgrades from VRP5.1 to VRP5.3, ISN8850 cannot create corresponding default route. Only single default route uplinks.
1. Compare port information of NE80E before upgrade and after upgrade. MAC address of all ports changes.
2. Update ARP bundling of upstream port on ISN8850. ISN8850 can create two default routes pointing to two NE80E and the problem is solved.
1. Check BAS MA5200G and two default routes can be formed. Check LSDB of ISN8850 and Type 5 LSA advertised by two NE80E can be seen. NE80E is not problematic.
2. Check ISN8850 configuration. It is found that upstream interface configures static ARP bundling. Bundled MAC address and MAC address of NE80E after upgrade are different.