這裡說明 DNS proxy 的行為
( p.s. 不是每個 DNS proxy 都是這樣做 )
CASE 1 :
若 DNS proxy 第一個 nameserver 是 IPv4 DNS server
Query A over IPv4 packet --> DNS proxy --> Query A over IPv4 packet
Query AAAA over IPv4 packet --> DNS proxy --> Query AAAA over IPv4 packet
Query A over IPv6 packet --> DNS proxy --> Query A over IPv4 packet
Query AAAA over IPv6 packet --> DNS proxy --> Query AAAA over IPv4 packet
CASE 2 :
若 DNS proxy 第一個 nameserver 是 IPv6 DNS server
Query A over IPv4 packet --> DNS proxy --> Query A over IPv6 packet
Query AAAA over IPv4 packet --> DNS proxy --> Query AAAA over IPv6 packet
Query A over IPv6 packet --> DNS proxy --> Query A over IPv6 packet
Query AAAA over IPv6 packet --> DNS proxy --> Query AAAA over IPv6 packet
由上面 2 個例子來看 , DNS proxy 送出的封包是根據 nameserver 來決定
若 nameserver 是 IPv4 , 則 DNS proxy 送出 IPv4 封包
若 nameserver 是 IPv6 , 則 DNS proxy 送出 IPv6 封包
CASE 3 :
假設 DNS proxy 有 2 個 nameserver
若 DNS proxy 第 1 個 nameserver 沒有回應
則 DNS proxy 會改用第 2 個 nameserver
注意 ! 是沒有回應才改用下一個 nameser
待續
看完文章請按 讚 or 推 , 感謝啦 ~