Guest wifi networks, do not have access to Custom DNS

[Chubbachops]

G’day

Within DNS, if you specify a Custom DNS with the Ignore Interface DNS setting enabled, DNS on the Guest WIFI will either fail (timeout) or after a very long time period revert to an unexpected DNS server

Technicolor DJA0231
Software Version 20.3.c
Firmware Version 20.3.c.0501-MR22.1-RA
tch-gui-unhide Version 2024.10.10@10:10

The issue can be worked around, by enabling the combination of the Ignore Interface DNS setting and then enabling the Auto-Discover WAN DNS setting The workaround will have much more latency than just a custom dns, as it still involves a timeout

The issue can be observed using https://dnsleaktest.com/

This likely isn’t an ideal workaround for people explicitly setting out to replace their ISP’s preferred DNS List on privacy grounds or to implement a parental filter like 1.1.1.3 but its okay if you sought an alternate DNS to simply lower latency.

[seud0nym]

If you are having DNS issues on your Guest Wi-Fi clients, the solution is to set the primary and secondary DNS on the Local Network -> Interfaces tab for the Guest1 and Guest_5GHz ALN Interfaces. This will ensure that those clients get the correct DNS resolvers, rather than relying on the DJA0231 DNS proxy.

The DNS card and its settings only apply to the device itself, not to client devices, although if you leave the primary/secondary DNS blank, it will use the DJA0231 as a DNS proxy. I am not sure why the proxy is not working for you on the Guest networks, but setting the DNS resolvers in Local Network will defintely fix it.