板卡ping不通某设备时，可以尝试用ipv6地址ssh进一步定位

1、换槽位排除硬件问题
2、在主控上tcpdump -i eth0 ip6
3、复位或拔插下板卡，记录2步中的ipv6地址
4、ipv6登录板卡
     ssh root@fe80::213:95ff:fe4f:fba8%eth0

[root@localhost ~]# tcpdump -i eth0 ip6
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
09:57:16.192431 IP6 :: > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28
09:57:16.330506 IP6 :: > ff02::1:ff4f:fba8: ICMP6, neighbor solicitation, who has fe80::213:95ff:fe4f:fba8, length 32
09:57:16.640427 IP6 :: > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28
09:57:16.703619 IP6 :: > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28
09:57:17.331419 IP6 fe80::213:95ff:fe4f:fba8 > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28
09:57:17.331439 IP6 fe80::213:95ff:fe4f:fba8 > ff02::2: ICMP6, router solicitation, length 16