랜카드 전체 다운(Link is Down)

한달동안 잘 버티고 있던 서버가... 어제 갑자기 메인보드 랜카드 제외 다른 랜카드가 꺼졌습니다... 재부팅시키니까 돼서 로그를 보니 

Oct 07 14:16:01 helgisnw kernel: r8169 0000:06:00.0 enp6s0: Link is Down
Oct 07 14:16:02 helgisnw kernel: tg3 0000:05:00.3 enp5s0f3: Link is down
Oct 07 14:16:02 helgisnw kernel: tg3 0000:05:00.2 enp5s0f2: Link is down
Oct 07 14:16:02 helgisnw kernel: tg3 0000:05:00.0 enp5s0f0: Link is down
Oct 07 14:16:02 helgisnw kernel: tg3 0000:05:00.1 enp5s0f1: Link is down
Oct 07 14:16:02 helgisnw kernel: vmbr0: port 1(enp6s0) entered disabled state
Oct 07 14:16:02 helgisnw kernel: vmbr3: port 1(enp5s0f3) entered disabled state
Oct 07 14:16:02 helgisnw kernel: vmbr2: port 1(enp5s0f2) entered disabled state
Oct 07 14:16:02 helgisnw kernel: vmbr1: port 1(enp5s0f0) entered disabled state
Oct 07 14:16:02 helgisnw kernel: vmbr4: port 1(enp5s0f1) entered disabled state
Oct 07 14:16:47 helgisnw kernel: r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control rx/tx
Oct 07 14:16:47 helgisnw kernel: vmbr0: port 1(enp6s0) entered blocking state
Oct 07 14:16:47 helgisnw kernel: vmbr0: port 1(enp6s0) entered forwarding state

이런 로그가 있더군요... 로그를 뒤져보니 저번에 이런 로그가 있긴했는데 1분도 안되서 다 살아나더라구요...

모든 포트가  Link is up이 되더라구요.... 왜그러는지 아시는 분 계시나요..