server-quic how is -fallback triggered?

Author: bcookatpcsdCreated Sep 12, 2026Updated Sep 16, 2026

bash

server-quic 149.112.112.112:853 \
        -host-ip 149.112.112.112 \
        -host-name dns.quad9.net \
        -tls-host-verify dns.quad9.net

(and)

server-h3 h3://1.0.0.2/dns-query \
        -host-name security.cloudflare-dns.com \
        -tls-host-verify security.cloudflare-dns.com \
        -http-host security.cloudflare-dns.com \
        -fallback

server-h3 h3://76.76.2.11/no-malware \
        -host-name freedns.controld.com \
        -tls-host-verify freedns.controld.com \
        -http-host freedns.controld.com \
        -fallback

when queries start going to the bottom two, fallback has been triggered..

what is happening to make the other two servers viable?

Thank you in advance.

Source: pymumu/smartdns

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