# LAN reachability and mDNS discovery shared by all machines. { ... }: { # Allow IPv4 ICMP echo requests so hosts can be found with ping. networking.firewall.allowPing = true; # Avahi/mDNS: publish .local and resolve other *.local LAN names. # Keep the multicast DNS firewall opening scoped to the Wi-Fi LAN interface. networking.firewall.interfaces.wlp8s0.allowedUDPPorts = [ 5353 ]; services.avahi = { enable = true; nssmdns4 = true; openFirewall = false; allowInterfaces = [ "wlp8s0" ]; publish = { enable = true; addresses = true; workstation = true; }; }; }