ping ipv6.baidu.com，为什么返回的是ipv4的地址？ping其他ipv6地址，报如下错误？

Question

Answer 1

第一个本来就不通，我这边也ping报错。百度本来就没有ipv6地址:

dig ipv6.baidu.com AAAA

; <<>> DiG 9.18.1 <<>> ipv6.baidu.com AAAA
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 6745
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;ipv6.baidu.com.                        IN      AAAA

;; ANSWER SECTION:
ipv6.baidu.com.         1       IN      CNAME   www.a.shifen.com.

;; AUTHORITY SECTION:
a.shifen.com.           1       IN      SOA     ns1.a.shifen.com. baidu_dns_master.baidu.com. 2203280012 5 5 2592000 3600

;; Query time: 30 msec
;; SERVER: 192.168.31.1#53(192.168.31.1) (UDP)
;; WHEN: Mon Mar 28 22:42:37 CST 2022
;; MSG SIZE  rcvd: 116

你试试ping一个支持ipv6地址的，比如:

ping mirrors.aliyun.com 
PING mirrors.aliyun.com(240e:bf:c800:2910:3::3fc (240e:bf:c800:2910:3::3fc)) 56 字节的数据
64 字节，来自 240e:bf:c800:2910:3::3fc (240e:bf:c800:2910:3::3fc): icmp_seq=1 ttl=57 时间=1.71 毫秒
64 字节，来自 240e:bf:c800:2910:3::3fc (240e:bf:c800:2910:3::3fc): icmp_seq=2 ttl=57 时间=1.68 毫秒
64 字节，来自 240e:bf:c800:2910:3::3fc (240e:bf:c800:2910:3::3fc): icmp_seq=3 ttl=57 时间=1.70 毫秒
64 字节，来自 240e:bf:c800:2910:3::3fc (240e:bf:c800:2910:3::3fc): icmp_seq=4 ttl=57 时间=1.76 毫秒
^C
--- mirrors.aliyun.com ping 统计 ---
已发送 4 个包， 已接收 4 个包, 0% packet loss, time 3002ms
rtt min/avg/max/mdev = 1.677/1.712/1.761/0.030 ms