Bug 130437 - RFE: support dhclient-${IF}.conf supersede, prepend, append options
Summary: RFE: support dhclient-${IF}.conf supersede, prepend, append options
Alias: None
Product: Fedora
Classification: Fedora
Component: system-config-network (Show other bugs)
(Show other bugs)
Version: rawhide
Hardware: All Linux
Target Milestone: ---
Assignee: Harald Hoyer
QA Contact:
Keywords: FutureFeature
: 99464 (view as bug list)
Depends On:
TreeView+ depends on / blocked
Reported: 2004-08-20 15:37 UTC by Jason Vas Dias
Modified: 2007-11-30 22:10 UTC (History)
3 users (show)

Fixed In Version:
Doc Type: Enhancement
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2007-11-13 11:53:22 UTC
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)

Description Jason Vas Dias 2004-08-20 15:37:19 UTC
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040510

Description of problem:
It would be nice if the network configuration gui would allow
users to configure their nameserver / domain search path options
with the dhcp-options 'prepend', 'append', or 'supersede' in 
/etc/dhclient-${interface}.conf - ie. /etc/dhclient-eth0.conf
if eth0 is being configured with DHCP.
Using these options, users can:
1. Change the search order for domains received from DHCP :
 ie. :
 'prepend domain-name "devel.redhat.com ";'
 will add "devel.redhat.com" to the domain-name list received from
 DHCP at the start of the "search" path in /etc/resolv.conf when the
 dhclient-script writes it;
 'append domain-name " devel.redhat.com";' would add it at the end,
 'supersede domain-name "devel.redhat.com";' would replace the 
 domain-name option received from the DHCP server entirely.

2. Change the domain-name-server list received from DHCP :
 ie. :
 'prepend domain-name-server;' 
 would make be queried  before nameservers recieved from
 'append domain-name-server;' would make be
 queried after nameservers recieved from DHCP; and
 'supersede domain-name-server;' replaces the nameservers
 returned by DHCP with
This would be very useful for users wishing to run a caching
nameserver, or for those users who get DHCP from a public ISP
but then need to connect to a VPN with private nameservers, or
anyone who gets DHCP settings that conflict with local preferences.

This would remove a source of many DHCP bugs and user confusion -
eg. bug #126637, bug #106275, bug #111208 ... (more!).

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. Set your nameserver or search options in /etc/resolv.conf
   to your local preferences
2. Bring a up DHCP interface 


Actual Results:   Your nameserver and search options in
/etc/resolv.conf have been
 wiped out!

Expected Results:   If those local preferences had been specified in
/etc/dhclient-${IF}.conf, they would have been retained.

Additional info:

Comment 1 Jason Vas Dias 2004-08-27 17:00:31 UTC
With an initscripts-7.66+ fix,  dhclient will now use the generic 
/etc/dhclient.conf (non-interface specific) if /etc/dhclient-${IF}.conf
is non-existent or empty - the generic /etc/dhclient.conf might be 
a more suitable place to put the prepend, append, supersede statements.

Comment 2 Jason Vas Dias 2005-06-03 18:52:21 UTC
*** Bug 99464 has been marked as a duplicate of this bug. ***

Comment 3 John Thacker 2006-10-29 22:01:07 UTC
Changing version to correct one.  (test1 -> fc3test1, and some were filed as
test3 accidentally instead; but clearly must be fc3test1 given the date of filing.)

Comment 4 Christian Iseli 2007-01-20 00:36:56 UTC
This report targets the FC3 or FC4 products, which have now been EOL'd.

Could you please check that it still applies to a current Fedora release, and
either update the target product or close it ?


Comment 5 Matthew Miller 2007-04-06 15:09:25 UTC
Fedora Core 3 and Fedora Core 4 are no longer supported. If you could retest
this issue on a current release or on the latest development / test version, we
would appreciate that. Otherwise, this bug will be marked as CANTFIX one month
from now. Thanks for your help and for your patience.

Comment 6 Steve Whitehouse 2007-05-01 13:17:41 UTC
On FC6 the config line:


added to the relavent ifcfg- file prevents overwrite of /etc/resolv.conf. There
is still a problem relating to default routes though as there is no similar
mechanism relating to those. I can override the DHCP supplied route, but what I
really want to do is just tell dhclient-script not to touch my current default
route. Perhaps we might add a PEERDEFAULT=no option too?

In fact, I think it can be argued that the behaviour is also wrong because I set
my default route up as a static route and I can see no reason why the
dhclient-script should touch it at all. If dhclient would have its own rtproto
number then it could be designed to only remove or replace routes which have an
rtproto of "kernel" or its own number. That would mean that it would play nicely
with any other dymanic/static routing which might be in use.

Should I start another bz or bump this one to FC6? I'm less worried about the
GUI side of things (I always edit the config files directly), but there ought to
be a suitable config option in the ifcfg file at least and the issue appears to
be the same.

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