Prevent upstream DNS queries of NCSI domain names#102
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This setting tells dnsmasq not to process IPv6 DNS queries for NCSI domains. Without this, dnsmasq returns randomly (?) response from IPv4 response from "host-record" or CNAME value from IPv6 query made to upstream. Later, the client resolves CNAME response to null-route (`address=/#/0.0.0.0`) which makes Windows clients to search NCSI responses from localhost.
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The discussed solutions did not result to desired outcome, but the IPv6 null-route Added also null-route to unknown IPv6 addresses, as discussed elsewhere. |
linuswillner
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Apr 13, 2026
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Without setting upstream DNS servers to none, the dnsmasq resolves the IPv6 addresses. In the case of NCSI servers the upstream server returns CNAME-record, which is resolved by dnsmasq to 127.0.0.1.
When client tries to get the valid NCSI response from 127.0.0.1 it obviously fails which causes NCSI to switch the network.