OSPFv3 cannot remove IPv6 routes that have no next hop？

[ChinHunghsing]

There are two devices running ospf6d and zebra. Device A's eth1 and Device B's eth2 form an adjacency. Before establishing the adjacency, IPv4 addresses from the same subnet were configured on eth1 and eth2. After the adjacency was established, some IPv6 prefixes were configured on eth1 without specifying a next hop. At this point, the peer device B learned these routes but also did not display a next hop. When certain IPv6 prefixes on eth1 were deleted from device A, an unusual issue occurred: only some routes were successfully deleted on both devices A and B, while others were not removed. However, if I add or remove the same IPv6 routes on other interfaces of device A, the deletion works normally. Alternatively, if IPv6 addresses (instead of IPv4) are configured before establishing the adjacency, and IPv6 routes are subsequently configured/deleted after the adjacency is formed, both devices can delete them properly. Could this be a bug? The logs are here:

"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] ospf6_install_lsa Install LSA: [Inter-Prefix Id:0.0.0.1 Adv:10.146.70.45] age 3600 seqnum 80000032 in LSDB."
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] Originating summary in area 0.0.0.1 for 3024:201:d0::/64 cost 15"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] The route has just removed, purge previous LSA"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] LSA: Premature aging: [Inter-Prefix Id:0.0.0.1 Adv:10.146.70.45]"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] LSA Expire:"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] [Inter-Prefix Id:0.0.0.1 Adv:10.146.70.45]"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] Age: 3600 SeqNum: 0x80000004 Cksum: d2d8 Len: 36"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] ospf6_install_lsa Install LSA: [Inter-Prefix Id:0.0.0.1 Adv:10.146.70.45] age 3600 seqnum 80000004 in LSDB."
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] Send remove route: 3024:201:d0::/64"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] Best-path removal resulted Sencondary addition"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] nexthop: fe80::fcfc:feff:fe0d:fd0%eth2(8)"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] area 1.0.0.1 route table 0xb2e730: route next: (nil)<-[0xa07150]->0xb3a890 , route ref count 2"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] area 1.0.0.1 route table 0xb2e730: route remove 0xa07150: 3024:201:d3::/64 cost 15 refcount 1"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] global route table 0xb1ac70: route remove 0xb3b5f0: 3024:201:d3::/64 cost 15 refcount 1"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] Originating summary in area 0.0.0.0 for 3024:201:d3::/64 cost 15"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] The route has just removed, purge previous LSA"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] LSA: Premature aging: [Inter-Prefix Id:0.0.0.2 Adv:10.146.70.45]"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] LSA Expire:"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] [Inter-Prefix Id:0.0.0.2 Adv:10.146.70.45]"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] Age: 3600 SeqNum: 0x80000029 Cksum: aed3 Len: 36"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] ospf6_install_lsa Install LSA: [Inter-Prefix Id:0.0.0.2 Adv:10.146.70.45] age 3600 seqnum 80000029 in LSDB."
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] Originating summary in area 0.0.0.1 for 3024:201:d3::/64 cost 15"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] The route has just removed, purge previous LSA"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] LSA: Premature aging: [Inter-Prefix Id:0.0.0.2 Adv:10.146.70.45]"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] LSA Expire:"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] [Inter-Prefix Id:0.0.0.2 Adv:10.146.70.45]"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] Age: 3600 SeqNum: 0x80000004 Cksum: f8ae Len: 36"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] ospf6_install_lsa Install LSA: [Inter-Prefix Id:0.0.0.2 Adv:10.146.70.45] age 3600 seqnum 80000004 in LSDB."
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] Send remove route: 3024:201:d3::/64"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] Best-path removal resulted Sencondary addition"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] nexthop: fe80::fcfc:feff:fe0d:fd0%eth2(8)"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] area 1.0.0.1 route table 0xb2e730: route next: (nil)<-[0xb3a890]->0xb4d090 , route ref count 2"
"2025-03-20 09:46:05","DEBUG","OSPF6D","00000000","[(null)] [0] area 1.0.0.1 route tabl

[ChinHunghsing]

I was removed 1212:abab:d0::/64 in the eth，but route -6 -n still can found this route，zebra log as bellow，who can help to explain ?

"2025-03-31 10:17:03","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_parse_info: netlink-listen (NS 0) type RTM_NEWNEIGH(28), len=76, seq=0, pid=0"
"2025-03-31 10:17:10","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_parse_info: netlink-listen (NS 0) type RTM_NEWNEIGH(28), len=76, seq=0, pid=0"
"2025-03-31 10:17:10","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_parse_info: netlink-listen (NS 0) type RTM_NEWNEIGH(28), len=76, seq=0, pid=0"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_parse_info: netlink-listen (NS 0) type RTM_DELADDR(21), len=72, seq=0, pid=0"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_interface_addr RTM_DELADDR eth1 flags 0x82:"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0]   IFA_ADDRESS   1212:abab:d0::1/64"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0]   IFA_CACHEINFO pref -1, valid -1"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] MESSAGE: ZEBRA_INTERFACE_ADDRESS_DELETE 1212:abab:d0::1/64 on eth1(0)"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] rib_delnode: 0:1212:abab:d0::/64: rn 0x7fef58000970, re 0x7fef58001260, removing"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] rib_delnode: 0:1212:abab:d0::/64 (MRIB): rn 0x7fef58000c30, re 0x7fef58000a80, removing"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] rib_update : AFI_IP event 0"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] rib_update : AFI_IP6 event 0"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] 0: IF eth1 IP 1212:abab:d0::/64 address down, scheduling MPLS processing"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] rib_update : AFI_IP event 0"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] rib_update : AFI_IP6 event 0"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] 0: IF eth1 IP 1212:abab:d0::1/64 address delete, scheduling MPLS processing"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_parse_info: netlink-listen (NS 0) type RTM_DELROUTE(25), len=116, seq=0, pid=0"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] RTM_DELROUTE ipv6  proto  NS 0"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_parse_info: netlink-listen (NS 0) type RTM_DELROUTE(25), len=116, seq=0, pid=0"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] RTM_DELROUTE ipv6 unicast proto kernel NS 0"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] 0:1212:abab:d0::/64: Updating route rn 0x7fef58000970, re 0x7fef58000eb0 (type 7) old 0x7fef58001260 (type 2)"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] Not Notifying Owner: 2 about prefix 1212:abab:d0::/64(254) 1 vrf: 0"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] zebra2proto: Please add this protocol(2) to proper rt_netlink.c handling"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_route_multipath(): RTM_DELROUTE 1212:abab:d0::/64 vrf 0(254)"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_talk: netlink-cmd (NS 0) type RTM_DELROUTE(25), len=56 seq=17 flags 0x401"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] netlink-cmd (NS 0): error: No such process type=RTM_DELROUTE(25), seq=17, pid=3024971197"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_route_multipath(): RTM_NEWROUTE 1212:abab:d0::/64 vrf 0(254)"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_route_multipath() (single-path): nexthop via if 13(0)"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_talk: netlink-cmd (NS 0) type RTM_NEWROUTE(24), len=64 seq=18 flags 0x401"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] Not Notifying Owner: 7 about prefix 1212:abab:d0::/64(254) 2 vrf: 0"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] 0:1212:abab:d0::/64: Redist update re 0x7fef58000eb0 (type 7), old 0x7fef58001260 (type 2)"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] zsend_redistribute_route: ZEBRA_REDISTRIBUTE_ROUTE_DEL to client ospf6: type connected, vrf_id 0, p 1212:abab:d0::/64"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] rib_process: 0:1212:abab:d0::/64: rn 0x7fef58000970, removing re 0x7fef58001260"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] rib_unlink: 0:1212:abab:d0::/64: rn 0x7fef58000970, re 0x7fef58001260"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] 0:1212:abab:d0::/64: Deleting route rn 0x7fef58000c30, re 0x7fef58000a80 (type 2)"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] 0:1212:abab:d0::/64: Redist delete re 0x7fef58000a80 (type 2)"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] zsend_redistribute_route: ZEBRA_REDISTRIBUTE_ROUTE_DEL to client ospf6: type connected, vrf_id 0, p 1212:abab:d0::/64"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] rib_process: 0:1212:abab:d0::/64 (MRIB): rn 0x7fef58000c30, removing re 0x7fef58000a80"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] rib_unlink: 0:1212:abab:d0::/64 (MRIB): rn 0x7fef58000c30, re 0x7fef58000a80"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] rib_gc_dest: 0:1212:abab:d0::/64 (MRIB): removing dest from table"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] 0: repeated route in fib rn 0x7fef58000970, re 0x7fef58000eb0 (type 7)"
"2025-03-31 10:17:49","DEBUG","ZEBRA","00000000","[(null)] [0] 0: Scheduling all LSPs upon RIB completion"
"2025-03-31 10:17:56","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_parse_info: netlink-listen (NS 0) type RTM_NEWNEIGH(28), len=76, seq=0, pid=0"
"2025-03-31 10:18:05","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_parse_info: netlink-listen (NS 0) type RTM_NEWNEIGH(28), len=76, seq=0, pid=0"
"2025-03-31 10:18:05","DEBUG","ZEBRA","00000000","[(null)] [0] netlink_parse_info: netlink-listen (NS 0) type RTM_NEWNEIGH(28), len=76, seq=0, pid=0"

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