Hi. On Fri, 25 Aug 2017 07:28:00 +0900 Mark Fletcher <mark2...@gmail.com> wrote:
> On Thu, Aug 24, 2017 at 11:35:25PM +0300, Reco wrote: > > On Thu, 24 Aug 2017 22:21:04 +0200 > > Pascal Hambourg <pas...@plouf.fr.eu.org> wrote: > > > > > Le 24/08/2017 à 11:30, Reco a écrit : > > > > > > > > Somewhat hackish, but straightforward way to achieve this is to redirect > > > > DNS requests from your LAN to correct DNS. Something like this should do > > > > the trick: > > > > > > Not so straightforward because you still need to get the ISP's DNS and > > > update the iptables rules whenever the DNS change. > > > > Appropriate dhclient hook should do this trick. > > I'd start with copying and modifying resolvconf one. > > > I think the concept of "appropriate dhclient hook" might be exactly what > I was after -- could an "appropriate dhclient hook" perhaps be used to > update the name servers being offered by the DHCP server? Sure it can. What you need is to copy /etc/dhcp/dhclient-enter-hooks.d/resolvconf under a different name and make changes in make_resolv_conf shell function. > And would that > be done by updating dhcp.conf and restarting the dhcp server, or would > that cause other problems? I don't see why it should. I still prefer iptables approach as that way you whole internal network will get new DNS immediately and not after the Airstation decide to renew DHCP lease. > And, is dhclient a separate piece of software from systemd.networkd? I was referring to a reference implementation - isc-dhcp-client. I honestly do not know if systemd-networkd utilizes these hooks. > Because I am using the latter at the moment to get the IP address from > the ISP on the firewall machine, although I am not married to that > method, it's just that it was super-easy to set up and worked first > time, so I never had reason to look for an alternative. Utilizing any other DHCP client is as simple as adding two lines in /etc/network/interfaces: auto <WAN interface> inet <WAN interface> inet dhcp Reco