dhcpcd-discuss

Hi

On 04/08/2017 09:08, Henning Schild wrote:
> i am using dhcpcd and am very happy with how it manages resolv.conf
> from various interfaces. But that magic quickly becomes a problem if
> something like a vpn client wants to manage that file. The copy of the
> client will get overwritten by dhcpcd all the time.
> 
> My solution to that is to start a dhcpcd with static ip_address routers
> domain_name_servers domain_name ... instead of letting the vpn client
> generate a resolv.conf. That works like a charm with i.e. the wifi
> dhcpcd that is running next to the tun one. Local names still resolve,
> after a while ... ;).
> 
> When the vpn clients shuts down i "dhcpcd -x tun" but that does not
> clear the injected values from resolv.conf, where i think it probably
> should. At least the nameservers seem to move down in the list.
> I am talking about v6.11.3 in case the problem is known and fixed.
> 
> I think that is a good way of dealing with resolv.conf issues, or does
> anyone have a better suggestion?

So there are two issues here:
1) contention for resolv.conf from seperate programs
2) resolv.conf isn't being cleaned up at program exit

Luckily both are easily solvable :)
1) Use resolvconf as a middleman - I also maintain openresolv
https://roy.marples.name/projects/openresolv

2) Comment out the persistent keyword in dhcpcd.conf
dhcpcd will then remove the lease (including IP address, routing, etc)
from the interface when it exits.

> Another issue i found is that "dhcpcd tun0" requires a "dhcpcd -x
> tun0-4" to match the PIDfile. I guess the number 4 is somehow generated
> when creating the file so the killing process should do the same steps
> to find that file.

This is because you limited tun0 to IPv4 only either in dhcpcd.conf or
the the commandline. As so it's expected because some users which to
control an IPv6 instance of dhcpcd seperately.

Roy