These people should run Split-horizon DNS;
| Host | Wrong IP address | Reason |
|---|---|---|
| 49-158-112-63.dynamic.elinx.com.tw | 0.0.0.0 | Unconfigured |
| 49-158-53-200.dynamic.elinx.com.tw | 0.0.0.0 | Unconfigured |
| 81-27-243-242.rascom.as20764.net | 10.6.6.6 | RFC 1918 |
| imap0.officemail.fi001.nl.intern.freedomnet.nl | 10.1.1.115 | RFC 1918 |
| none.underplatform.com | 192.168.6.177 | RFC 1918 |
| ns1.gmaxtelecom.com.br | fe80::2ca8:7dff:fe05:7be5 | IPv6 Link local |
| ns2.j2global.com | 0.0.0.0 | Unconfigured |
Last update: Tue 5 Aug 06:02:01 UTC 2025
You can block answers like these with Bind's 'deny-answer-addresses' feature;
deny-answer-addresses {
// Unconfigured
0.0.0.0;
// RFC 1918
10.0.0.0/8;
172.16.0.0/12;
192.168.0.0/16;
// RFC 3927
169.254.0.0/16;
// IPv6
// :: to ::ffff:ffff:ffff.
// Includes ::, ::1, IPv4-Compatible IPv6 Addresses ::/96,
// and IPv4-mapped IPv6 addresses ::ffff:0:0/96
::/80;
// RFC 6052
64:ff9b::/96;
// Reserved for Documentation
2001:db8::/32;
// IPv6 Unique Local
fc00::/7;
// IPv6 Link local
fe80::/10;
// IPv6 Site local
fec0::/10;
// Your IPv6 address range(s)
Net/Mask
} except-from { "Your.Domain"; };
deny-answer-aliases { "Your.Domain"; };
The produces log entries like;
Aug 21 19:31:01 sput named[1601]: answer address 10.0.0.100 denied for spacefon.com/A/IN
Not blocking these addresses can be a serious security risk.