When the interface is down, a small number of routes are deleted without notifying fpm.

[wangdan1323]

Description

When the interface is down, a small number of routes are deleted without notifying fpm.

Version

FRR 8.5

How to reproduce

A --- B (1) B learns 19k ipv6 bgp route from A----must be ipv6 routes and a large number (2) B Down the interface connected to A.

Expected behavior

When the interface is down, all routes are deleted with notifying fpm.

Actual behavior

When the interface is down, a small number of routes are deleted without notifying fpm.

Additional context

I notice in rib_delete /*

• This is a non FRR route
• as such we should mark
• it as deleted / dest->selected_fib = NULL; result when rib_process process / Update fib according to selection results */ if (new_fib && old_fib) rib_process_update_fib(zvrf, rn, old_fib, new_fib); else if (new_fib) rib_process_add_fib(zvrf, rn, new_fib); else if (old_fib) rib_process_del_fib(zvrf, rn, old_fib); old_fib is NULL， cannot rib_process_del_fib。

Backtrace: rib_delete+0x42d 56375cb8befd 7ffc94977940 /usr/lib/frr/zebra (mapped at 0x56375cb08000) vrf_lookup_by_table+0x905 56375cb4a2d5 7ffc94977a90 /usr/lib/frr/zebra (mapped at 0x56375cb08000) netlink_route_change+0xd3 56375cb4b053 7ffc94977fa0 /usr/lib/frr/zebra (mapped at 0x56375cb08000) netlink_parse_info+0x177 56375cb40e97 7ffc94977ff0 /usr/lib/frr/zebra (mapped at 0x56375cb08000) netlink_parse_info+0x445 56375cb41165 7ffc949800d0 /usr/lib/frr/zebra (mapped at 0x56375cb08000) thread_call+0x56 7f58df218e96 7ffc94980160 /usr/lib64/libfrr.so.0 (mapped at 0x7f58df185000) frr_run+0xe8 7f58df1e0658 7ffc94980300 /usr/lib64/libfrr.so.0 (mapped at 0x7f58df185000) main+0x329 56375cb31df9 7ffc94980530 /usr/lib/frr/zebra (mapped at 0x56375cb08000) libc_init_first+0x90 7f58dec7c390 7ffc94980670 /usr/lib64/libc.so.6 (mapped at 0x7f58dec4f000) libc_start_main+0x7c 7f58dec7c43c 7ffc94980710 /usr/lib64/libc.so.6 (mapped at 0x7f58dec4f000) _start+0x25 56375cb32775 7ffc94980780 /usr/lib/frr/zebra (mapped at 0x56375cb08000)

Checklist

• [X] I have searched the open issues for this bug.
• [X] I have not included sensitive information in this report.

[donaldsharp]

Can you give us an idea of which routes are not deleted through the FPM? Could you turn on debug zebra dplane detailed and debug zebra rib when this problem ocurrs

[wangdan1323]

See attachment for log。 routes are deleted without notifying fpm： 100::af1" 100::aff" 100::b10" 100::afa" 100::af3" 100::b09" 100::afd" 100::b17" 100::b16" 100::b04" 100::b0f" 100::b03" 100::b07 100::af0 100::af5 100::b12 100::afb 100::b0a 100::b02 100::b08 100::afe 100::b0b 100::af8 100::af7 100::b00 100::b0c 100::af9 100::af4 100::b0d 100::b06 100::af6 100::b01 100::b11 100::b13 100::b0e 100::b14 100::b15 100::af2 100::afc 100::b05

[wangdan1323]

you can analyze 100::b02