After upgrading to 1.6.8, no problem seems to occur.
Of course, I can upgrade to version 2.0.x and check, but My question is whether there is a bug related to this problem.

2020년 6월 19일 (금) 오전 11:07, Brian Topping <brian.topping@gmail.com>님이 작성:

> On Jun 18, 2020, at 19:50, seunghwan hwang <seunghwan.hwang99@gmail.com> wrote:
>
> I think BGP Keepalive packets can't be transmitted to the BIRD(from the kernel).
> Is there an issue related to this in this version?

Instead of waiting until morning for others to maybe say the same thing, I would put effort into getting the latest version installed first.