On Mar 26, 2004, at 2:33 PM, Christos Zoulas wrote:

> On Mar 26,  2:24pm, ipthomas@mac.com (Ian Thomas) wrote:
> -- Subject: Re: dhclient-script question regarding resolv.conf
>
> | The contents of /etc/dhclient.conf
> |
> | # DHCP setup options.
> | interface "rtk0"
> | {
> | 	send host-name "my.domain.org";
> |          	request subnet-mask, broadcast-address, routers,
> | domain-name-servers;
> |          	require subnet-mask, domain-name-servers;
> |          	script  "/sbin/dhclient-script";
> | }
>
> mine looks like:
>
> timeout 60;
> retry 120;
> reboot 10;
> select-timeout 10;
> initial-interval 2;
>
> interface "ep0" {
>     supersede host-name "stinky.astron.com";
>     supersede domain-name "astron.com gw.com";
>     supersede nis-domain "";
>     prepend domain-name-servers 127.0.0.1, 192.168.2.9;
>     request subnet-mask, broadcast-address, routers,
>         domain-name, domain-name-servers, host-name;
>     require subnet-mask, routers;
>     script "/sbin/dhclient-script";
> }

	The proverbial light-bulb came on as I was looking at the man page for 
dhclient.conf(5).

1. By default, the DHCP server requests the ... domain-name, 
domain-name-servers, and ...

If the DHCP server doesn't get a value for its request for a 
domain-name, then resolv.conf will not be created unless you specify a 
domain-name value in your dhclient.conf file.  By adding

supersede domain-name "domain.org";

a copy of resolv.conf was generated.  The values in the file 
dhclient-script: new_domain_name and new_domain_name_servers;  
correspond to the values domain-name and domain-name-servers in the 
file dhclient.conf, respectively.
	Should the logic in the function make_resolv_conf be changed to allow 
for the situation when just domain-name-servers are sent without a 
domain-name, and vice-versa?  resolv.conf can do its job with either 
the search or nameserver option filled in.  Maybe just generate a 
resolv.conf file containing two comments like if the DHCP server fails 
to give either a domain-name or domain-name-servers.

ex.
# Created by dhclient ...
# No domain-name or nameservers could be found.

	This would allow a person just setting up a box on a network using 
DHCP to not have to create a dhclient.conf file at all because the 
defaults would "do-the-right-thing".  Just a suggestion to make DHCP 
more user-friendly.  Appreciate the help.


Ian