.is 的域名 Nameserver 要如何配置？

[wuxqing]

直接加 NS 会报错，说是 nameserver 没登记

尝试登记 cloudxns 的 NS
结果报错
Nameserver lv3ns1.ffdns.net does not appear to comply with ISNIC's technical requirements

Please note that in order for a nameserver to host .IS domains it must comply with the technical requirements set forth here.

Test result # CHK-20170724.022915 for lv3ns1.ffdns.net:
The nameserver LV3NS1.FFDNS.NET is not correctly registered in DNS (The PTR RRset for 34.201.177.100 does not include the name LV3NS1.FFDNS.NET)
The nameserver LV3NS1.FFDNS.NET is not correctly registered in DNS (The PTR RRset for 54.153.30.23 does not include the name LV3NS1.FFDNS.NET)
The nameserver LV3NS1.FFDNS.NET (34.201.177.100) seems to reject connections to TCP port 53
The nameserver LV3NS1.FFDNS.NET (54.153.30.23) seems to reject connections to TCP port 53

试了 dnspod 也一样报错

[airyland]

以前有个 is 域名，最后用 cloudflare 的 dns。

[CinderellaCiCi]

is 域名，需要 NS 支持 TCP 和 PTR 反向解析。。
国内现在貌似暂时没有支持的。