從我的 DNS server 解析結果
$ host www.treasury.gov
www.treasury.gov is a nickname for www.georedirector.treasury.akadns.net
www.georedirector.treasury.akadns.net is a nickname for www.treasury.gov.edgesuite.net
www.treasury.gov.edgesuite.net is a nickname for a756.b.akamai.net
a756.b.akamai.net has address 203.69.113.135
a756.b.akamai.net has address 203.69.113.143

用 dig 查的結果
$ dig a756.b.akamai.net any
a756.b.akamai.net. 20S IN A 203.69.113.135
a756.b.akamai.net. 20S IN A 203.69.113.143

從 168.95.1.1 解析結果
$ host www.treasury.gov 168.95.1.1
Using domain server 168.95.1.1:
www.treasury.gov is a nickname for www.georedirector.treasury.akadns.net
www.georedirector.treasury.akadns.net is a nickname for www.treasury.gov.edgesuite.net
www.treasury.gov.edgesuite.net is a nickname for a756.b.akamai.net
a756.b.akamai.net has address 203.69.138.11
a756.b.akamai.net has address 203.69.138.40

從 8.8.8.8 解析結果
$ host www.treasury.gov 8.8.8.8
Using domain server 8.8.8.8:
www.treasury.gov is a nickname for www.georedirector.treasury.akadns.net
www.georedirector.treasury.akadns.net is a nickname for www.treasury.gov.edgesuite.net
www.treasury.gov.edgesuite.net is a nickname for a756.b.akamai.net
a756.b.akamai.net has address 23.15.9.136
a756.b.akamai.net has address 23.15.9.154

**www.treasury.gov 有使用 akamai.net 服務,
它會根據dns query來源決定, 該回應給哪個它們認為最接近你的站台.**就你目前的情況與需要, 把
203.69.138.11 , 203.69.138.40 ,
以及你的 DNS 查到的該主機IP ,
列入開放 FW 名單即可.

但, 留意到這些 akamai 主機的 TTL 非常短(20S),
也就是, 它有可能因應需要而即時調整.

如果, 能夠知道 akamai.net 在台灣的網段有那些, 可能會比較好辦.

在內部 DNS server 上動手腳, 加上 www.treasury.gov 對應到固定的幾筆 IP
address.
FW 再開放這幾個 IP address 就好.