On Sun, 2025-03-02 at 20:38 +0100, Patrick Dupre via users wrote:
Trying to add a nameserver.
On PC B, I have Global Protocols: LLMNR=resolve -mDNS -DNSOverTLS DNSSEC=no/unsupported resolv.conf mode: stub
Link 2 (enp3s0) Current Scopes: LLMNR/IPv4 LLMNR/IPv6 Protocols: -DefaultRoute LLMNR=resolve -mDNS -DNSOverTLS DNSSEC=no/unsupported
Link 3 (wlp2s0) Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6 Protocols: +DefaultRoute LLMNR=resolve -mDNS -DNSOverTLS DNSSEC=no/unsupported Current DNS Server: 192.168.43.1 DNS Servers: 192.168.43.1
On PC A
Global Protocols: LLMNR=resolve -mDNS -DNSOverTLS DNSSEC=no/unsupported resolv.conf mode: stub
Link 2 (enp1s0) Current Scopes: LLMNR/IPv4 LLMNR/IPv6 Protocols: -DefaultRoute LLMNR=resolve -mDNS -DNSOverTLS DNSSEC=no/unsupported
Link 3 (enp2s0) Current Scopes: LLMNR/IPv4 LLMNR/IPv6 Protocols: -DefaultRoute LLMNR=resolve -mDNS -DNSOverTLS DNSSEC=no/unsupported
Link 4 (virbr0) Current Scopes: none Protocols: -DefaultRoute LLMNR=resolve -mDNS -DNSOverTLS DNSSEC=no/unsupported
What should I set on this PC A?
resolvectl dns enps2s0 192.168.43.1 systemctl restart systemd-resolved
With what we're presuming to be your network topology, and the usual way things are done when sharing an internet connection, and presuming you just want a DNS server that lets everyone surf the internet rather than be a resolver of local addresses:
WiFi mobile 192.168.43.1 | | 192.168.43.115 PC B (acting as a gateway) 10.42.0.1 | | 10.42.0.5 PC A
B should be using the 192.168.43.1 device as its DNS server, and A should be using B (10.42.0.1) as its DNS server. B should be behaving like some kind of forwarder for the name resolution requests (either acting as a kind of proxy, answering them itself, or just redirecting IP packets through to the mobile device and using it as the DNS server).
And it might be worth having a look at this:
https://fedoramagazine.org/internet-connection-sharing-networkmanager/
It's a bit old, but might say something helpful.