My machine has a static IP, with dhcp and IPv6 disabled. Every time I reboot, some process rewrites /etc/resolv.conf, including a comment about dhcpclient. The only package I have installed that shows up in "rpm -qa|grep -i dhcp" is dhcpv6-client-1.0.10-16.el5, and nothing in there is named dhcpclient.
I'd like to figure out what software is rewriting this file and why. man 5 resolv.conf and man resolver are unhelpful in this case. rpm reports /etc/resolv.conf is not owned by any package.
At this point, I am as (or more) interested in pointers regarding how to find the answer as I am in the actual answer. Please teach me to fish.
mahalo, Dave
On Thu, Oct 8, 2009 at 10:41 AM, Dave tdbtdb+centos@gmail.com wrote:
My machine has a static IP, with dhcp and IPv6 disabled. Every time I reboot, some process rewrites /etc/resolv.conf, including a comment about dhcpclient. The only package I have installed that shows up in "rpm -qa|grep -i dhcp" is dhcpv6-client-1.0.10-16.el5, and nothing in there is named dhcpclient.
I don't know that answer, but one workaround would be to maintain a backup copy of the file and initiate a late-boot service that replaces the rewritten one with the backup if they don't match.
mhr
On Thu, Oct 8, 2009 at 1:41 PM, Dave tdbtdb+centos@gmail.com wrote:
My machine has a static IP, with dhcp and IPv6 disabled. Every time I reboot, some process rewrites /etc/resolv.conf, including a comment about dhcpclient. The only package I have installed that shows up in "rpm -qa|grep -i dhcp" is dhcpv6-client-1.0.10-16.el5, and nothing in there is named dhcpclient.
Looks like the dhclient script is still being called.
One option would be to comment out the make_resolv_conf() function in /sbin/dhclient-script.
M
Meenoo Shivdasani wrote:
One option would be to comment out the make_resolv_conf() function in /sbin/dhclient-script.
That's the last-ditch solution. Never use it, unless everything else fails.
Hi,
One option would be to comment out the make_resolv_conf() function in /sbin/dhclient-script.
btw. a more common way would be to create a /etc/dhclient-enter-hooks
with the following content:
make_resolv_conf(){
:
}
Best Regards Marcus
Maybe it overwritten by NetworkManager?
On Thu, Oct 8, 2009 at 9:41 PM, Dave <tdbtdb+centos@gmail.comtdbtdb%2Bcentos@gmail.com
wrote:
My machine has a static IP, with dhcp and IPv6 disabled. Every time I reboot, some process rewrites /etc/resolv.conf, including a comment about dhcpclient. The only package I have installed that shows up in "rpm -qa|grep -i dhcp" is dhcpv6-client-1.0.10-16.el5, and nothing in there is named dhcpclient.
I'd like to figure out what software is rewriting this file and why. man 5 resolv.conf and man resolver are unhelpful in this case. rpm reports /etc/resolv.conf is not owned by any package.
At this point, I am as (or more) interested in pointers regarding how to find the answer as I am in the actual answer. Please teach me to fish.
mahalo, Dave _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
On Thu, Oct 8, 2009 at 7:52 AM, Sergey Smirnov sergey.a.smirnov@gmail.com wrote:
Maybe it overwritten by NetworkManager?
I almost wish.
[root@ ~]# /etc/init.d/NetworkManager status NetworkManager is stopped [root@ ~]# chkconfig --list|grep Netw NetworkManager 0:off 1:off 2:off 3:off 4:off 5:off 6:off
Dave wrote:
On Thu, Oct 8, 2009 at 7:52 AM, Sergey Smirnov sergey.a.smirnov@gmail.com wrote:
Maybe it overwritten by NetworkManager?
I almost wish.
[root@ ~]# /etc/init.d/NetworkManager status NetworkManager is stopped [root@ ~]# chkconfig --list|grep Netw NetworkManager 0:off 1:off 2:off 3:off 4:off 5:off 6:off _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Hi
Try adding PEERDNS=no to /etc/sysconfig/network :)
Clint Dilks wrote:
Try adding PEERDNS=no to /etc/sysconfig/network :)
aw, man :)
This is not fixing the leaking faucet. It's hammering the water pipe shut instead.
aw, man :)
This is not fixing the leaking faucet. It's hammering the water pipe shut instead.
Huh, what r u talking about? This is the right way to do this. Check the deployment docs on network scripts.
Joseph L. Casale wrote:
aw, man :)
This is not fixing the leaking faucet. It's hammering the water pipe shut instead.
Huh, what r u talking about? This is the right way to do this. Check the deployment docs on network scripts.
Yes, I know the docs. What I was saying is - it will not help finding the cause, which is what the OP requested. It will just make the problem go away.
Yes, I know the docs. What I was saying is - it will not help finding the cause, which is what the OP requested. It will just make the problem go away.
Uhm, am I missing something? It *is* the cause? Its designed to do just what it's doing, and here's a real shocker, it's doing it:)
Joseph L. Casale wrote:
Yes, I know the docs. What I was saying is - it will not help finding the cause, which is what the OP requested. It will just make the problem go away.
Uhm, am I missing something? It *is* the cause? Its designed to do just what it's doing, and here's a real shocker, it's doing it:)
Take a step back and look at the whole picture.
Your suggestion will override a DHCP-related config item somewhere else.
Yes, it will likely stop the system from over-writing resolv.conf - in that, you are correct.
No, it will not satisfy the requirement of the the o.p. which was, I quote: "At this point, I am as (or more) interested in pointers regarding how to find the answer as I am in the actual answer. Please teach me to fish."
What I'm trying to do here is to help the o.p. to find what causes the modification of resolv.conf, not how to cover up the issue. It's easy to hide the problem, either do what you suggest, or edit away make_resolv_conf(). But the underlying cause will remain, and may resurface if these changes are undone.
about dhcpclient. The only package I have installed that shows up in
It's called "dhclient", so searching for "dhcp" won't give you a hit on that.
chkconfig for dhclient too, and see what that results.
Also, look at /etc/sysconfig/network-scripts/ifcfg-eth0.
It's possible to have addresses "statically" assigned via DHCP based on MAC addresses. If resolv.conf is getting populated by dhclient, then I'm guessing the odds of you having a dhcp server on your network is good. :)
In all likelihood, you have a static IP assigned in your ifcfg-eth0, and the resolv.conf is being over-written by dhclient.
On Thu, Oct 8, 2009 at 9:49 AM, Spiro Harvey spiro@knossos.net.nz wrote:
chkconfig for dhclient too, and see what that results.
[root@ ~]# chkconfig --list|grep -e dh -e clie [root@ ~]#
Also, look at /etc/sysconfig/network-scripts/ifcfg-eth0.
[root@lee1 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 # Broadcom Corporation NetXtreme BCM5751 Gigabit Ethernet PCI Express DEVICE=eth0 BOOTPROTO=none HWADDR=00:18:8b:0f:ad:c2 IPADDR=1[snip]0 ONBOOT=yes DHCP_HOSTNAME=[snip] DNS1=1[snip]0 DNS2=1[snip].2 NM_CONTROLLED=no SEARCH=[snip] NETMASK=255.255.255.0 DNS3=1[snip]0 GATEWAY=1[snip]0.1 TYPE=Ethernet USERCTL=no PEERDNS=yes IPV6INIT=no
It's possible to have addresses "statically" assigned via DHCP based on MAC addresses. If resolv.conf is getting populated by dhclient, then I'm guessing the odds of you having a dhcp server on your network is good. :)
You guessed right. But the question remains, what software is writing the file?
In all likelihood, you have a static IP assigned in your ifcfg-eth0, and the resolv.conf is being over-written by dhclient.
What is invoking dhclient, how do I find it? rpm -qR dhclient /bin/bash initscripts >= 6.75 libc.so.6()(64bit) libc.so.6(GLIBC_2.2.5)(64bit) libc.so.6(GLIBC_2.3)(64bit) libc.so.6(GLIBC_2.3.4)(64bit) libc.so.6(GLIBC_2.4)(64bit) libc.so.6(GLIBC_2.8)(64bit) rpmlib(CompressedFileNames) <= 3.0.4-1 rpmlib(PayloadFilesHavePrefix) <= 4.0-1 rpmlib(VersionedDependencies) <= 3.0.3-1 rtld(GNU_HASH)
Dave
You guessed right. But the question remains, what software is writing the file?
/etc/init.d/network calls /etc/sysconfig/network-scripts/ifup which calls /sbin/dhclient which calls /sbin/dhclient-script which overwrites your resolv.conf with the info it gets from the DHCP server on the network.
M
On Thu, Oct 8, 2009 at 11:27 AM, Meenoo Shivdasani meenoo@gmail.com wrote:
/etc/init.d/network calls /etc/sysconfig/network-scripts/ifup which calls /sbin/dhclient which calls /sbin/dhclient-script which overwrites your resolv.conf with the info it gets from the DHCP server on the network.
How would I find this out on my own? And it seems not to be correct. At least, if /etc/sysconfig/network-scripts/ifup calls /sbin/dhclient, it must use some indirection, as dhclient is not mentioned in the script explicitly:
grep -i dhc /etc/sysconfig/network-scripts/ifup if [ "${BOOTPROTO}" = "bootp" -o "${BOOTPROTO}" = "dhcp" ]; then
Why does it overwrite /etc/resolv.conf when the machine is not set to use DHCP? The IP address etc. is set statically using /usr/bin/system-config-network.
Dave
On Thu, Oct 8, 2009 at 5:39 PM, Dave tdbtdb+centos@gmail.com wrote:
On Thu, Oct 8, 2009 at 11:27 AM, Meenoo Shivdasani meenoo@gmail.com wrote:
/etc/init.d/network calls /etc/sysconfig/network-scripts/ifup which calls /sbin/dhclient which calls /sbin/dhclient-script which overwrites your resolv.conf with the info it gets from the DHCP server on the network.
And it seems not to be correct.
At least, if /etc/sysconfig/network-scripts/ifup calls /sbin/dhclient, it must use some indirection, as dhclient is not mentioned in the script explicitly:
My bad -- on the 4.x system I referred to, ifup is where it's called.
On my 5.x system, it's called by ifup-eth.
Why does it overwrite /etc/resolv.conf when the machine is not set to use DHCP? The IP address etc. is set statically using /usr/bin/system-config-network.
Are there any interfaces that have BOOTPROTO=dhcp? Perhaps one that's not connected to the network?
grep BOOTPROTO /etc/sysconfig/network-scripts/ifcfg*
How would I find this out on my own?
That's a harder one to answer. I would start with the comment that got added to the resolv.conf file -- and Google resolv.conf dhclient. That brings up hits that describe several ways of avoiding the whole issue (and confirms for you that you're on the right track). man dhclient mentions dhclient-script, then poking around in various etc directories gets you to where it gets called from.
Making the leap to figuring out that PEERDNS is one of the ways that you can control whether or not resolv.conf gets modified would mean looking through the various definitions in ifcfg-eth0 and making sure that you know what each one does. When you hit one that you don't recognize, look it up. In this case:
PEERDNS=<answer>, where <answer> is one of the following: yes — Modify /etc/resolv.conf if the DNS directive is set. If using DCHP, then yes is the default. no — Do not modify /etc/resolv.conf.
M
On Thu, Oct 8, 2009 at 11:57 AM, Meenoo Shivdasani meenoo@gmail.com wrote:
Are there any interfaces that have BOOTPROTO=dhcp? Perhaps one that's not connected to the network?
grep BOOTPROTO /etc/sysconfig/network-scripts/ifcfg*
grep BOOTPROTO /etc/sysconfig/network-scripts/ifcfg* /etc/sysconfig/network-scripts/ifcfg-eth0:BOOTPROTO=none
mahalo, Dave
On Thu, Oct 8, 2009 at 4:39 PM, Dave tdbtdb+centos@gmail.com wrote:
On Thu, Oct 8, 2009 at 11:27 AM, Meenoo Shivdasani meenoo@gmail.com wrote:
/etc/init.d/network calls /etc/sysconfig/network-scripts/ifup which calls /sbin/dhclient which calls /sbin/dhclient-script which overwrites your resolv.conf with the info it gets from the DHCP server on the network.
How would I find this out on my own? And it seems not to be correct. At least, if /etc/sysconfig/network-scripts/ifup calls /sbin/dhclient, it must use some indirection, as dhclient is not mentioned in the script explicitly:
grep -i dhc /etc/sysconfig/network-scripts/ifup if [ "${BOOTPROTO}" = "bootp" -o "${BOOTPROTO}" = "dhcp" ]; then
Why does it overwrite /etc/resolv.conf when the machine is not set to use DHCP? The IP address etc. is set statically using /usr/bin/system-config-network.
Dave _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
i feel the pain as i went through this just last night on a multihomed CentOS 5.3 box. It was using old and wrong lease info which helped me notice it as a problem.
i ended up deleting:
/var/lib/dhcpd/dhclient.leases /var/lib/dhcpd/dhclient.leases~ /etc/dhclient.conf (but you should make a backup or at least look at the dhclient.conf because i think you can tell it what ethX to work on or not). rm anything else associated with dhclient
Some guys say to uninstall NetworkManager, not just keep it from running.
Setting a static dhcp lease in our separate dhcpd server you would think would fix this. But static lease made things worse because dhclient broke /etc/sysconfig/network-scripts/ifup-routes calls to '/sbin/ip/route add" and "/sbin/ip/rule add". With dhclient, i could not set a default gw rule for each different network interface card. After deleting the lease info and maybe changing the /etc/dhclient.conf and then deleting it, i could have a separate default gateway for each nic.
Ok, the other BUG is ping. There is a bug in ping that has sucked up much of my life for the last 2 or 3 years. i will post separately on the ping -I bug.
On Thu, 2009-10-08 at 11:19 -1000, Dave wrote:
On Thu, Oct 8, 2009 at 9:49 AM, Spiro Harvey spiro@knossos.net.nz wrote:
chkconfig for dhclient too, and see what that results.
[root@ ~]# chkconfig --list|grep -e dh -e clie [root@ ~]#
Also, look at /etc/sysconfig/network-scripts/ifcfg-eth0.
[root@lee1 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 # Broadcom Corporation NetXtreme BCM5751 Gigabit Ethernet PCI Express DEVICE=eth0 BOOTPROTO=none HWADDR=00:18:8b:0f:ad:c2 IPADDR=1[snip]0 ONBOOT=yes DHCP_HOSTNAME=[snip] DNS1=1[snip]0 DNS2=1[snip].2 NM_CONTROLLED=no SEARCH=[snip] NETMASK=255.255.255.0 DNS3=1[snip]0 GATEWAY=1[snip]0.1 TYPE=Ethernet USERCTL=no PEERDNS=yes
- ^^^^^^^^^^^ change to PEERDNS=no
Craig
On Thu, Oct 8, 2009 at 11:44 AM, Craig White craigwhite@azapple.com wrote:
On Thu, 2009-10-08 at 11:19 -1000, Dave wrote:
[root@lee1 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
[snip]
PEERDNS=yes
- ^^^^^^^^^^^
change to PEERDNS=no
What man page would tell me what this means? How should I have known that's what I should do, if I were lacking the luxury of being told by one wiser than myself?
rpm -qf /etc/sysconfig/network-scripts/ifcfg-eth0 file /etc/sysconfig/network-scripts/ifcfg-eth0 is not owned by any package man ifcfg No manual entry for ifcfg man ifcfg-eth0 No manual entry for ifcfg-eth0
mahalo, Dave
Quoting Dave tdbtdb+centos@gmail.com:
On Thu, Oct 8, 2009 at 11:44 AM, Craig White craigwhite@azapple.com wrote:
On Thu, 2009-10-08 at 11:19 -1000, Dave wrote:
[root@lee1 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
[snip]
PEERDNS=yes
- ^^^^^^^^^^^
change to PEERDNS=no
What man page would tell me what this means? How should I have known that's what I should do, if I were lacking the luxury of being told by one wiser than myself?
/usr/share/doc/initscripts-*/sysconfig.txt
On Thu, Oct 8, 2009 at 11:57 AM, Barry Brimer lists@brimer.org wrote:
Quoting Dave tdbtdb+centos@gmail.com:
On Thu, Oct 8, 2009 at 11:44 AM, Craig White craigwhite@azapple.com wrote:
On Thu, 2009-10-08 at 11:19 -1000, Dave wrote:
[root@lee1 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
[snip]
PEERDNS=yes
- ^^^^^^^^^^^
change to PEERDNS=no
What man page would tell me what this means? How should I have known that's what I should do, if I were lacking the luxury of being told by one wiser than myself?
/usr/share/doc/initscripts-*/sysconfig.txt
Wow, there it is. I guess I could've found it by doing a careful search of the initscripts package, which contains/owns /etc/sysconfig/network-scripts/ifcfg-eth0, which was the only script in /etc/ that invokes /sbin/dhclient, which a comment in /etc/resolv.conf revealed to be the program that wrote it.
Thanks guys, Dave
On Thu, Oct 08, 2009 at 01:32:39PM -1000, Dave wrote:
On Thu, Oct 8, 2009 at 11:57 AM, Barry Brimer lists@brimer.org wrote:
Quoting Dave tdbtdb+centos@gmail.com:
On Thu, Oct 8, 2009 at 11:44 AM, Craig White craigwhite@azapple.com wrote:
On Thu, 2009-10-08 at 11:19 -1000, Dave wrote:
[root@lee1 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
[snip]
PEERDNS=yes
- ^^^^^^^^^^^
change to PEERDNS=no
What man page would tell me what this means? How should I have known that's what I should do, if I were lacking the luxury of being told by one wiser than myself?
/usr/share/doc/initscripts-*/sysconfig.txt
Wow, there it is. I guess I could've found it by doing a careful search of the initscripts package, which contains/owns /etc/sysconfig/network-scripts/ifcfg-eth0, which was the only script in /etc/ that invokes /sbin/dhclient, which a comment in /etc/resolv.conf revealed to be the program that wrote it.
Just one of those things you kind of pick up as you go along and remember. Tribal knowledge if you will.
Where exactly did you attempt to look first? I'm just trying to think of where a more obvious place to look would be first. Perhaps a man page documenting all the ifcfg type settings? man ifcfg?
Ray
Just one of those things you kind of pick up as you go along and remember. Tribal knowledge if you will.
There's two pdf's and one command I use "often" :)
The redhat 5.3 deployment and installation pdf's (or the online versions) and:
# find /usr/share/doc/ -exec grep "PEERDNS" '{}' ; -print PEERDNS=yes|no file if PEERDNS is not set to "no". /usr/share/doc/initscripts-8.45.25/sysconfig.txt honor PEERDNS=no for pump and dhcpcd too (#18619) DEFROUTE defaults on; PEERDNS documented and defaults on /usr/share/doc/initscripts-8.45.25/ChangeLog
Now you know what doc to read...
Also: man -K PEERDNS But that's generally a slow and last ditch effort even after google:) It also never helped with this string but its useful to know.
On Fri, 2009-10-09 at 00:54 +0000, Joseph L. Casale wrote:
<snip>
Also: man -K PEERDNS But that's generally a slow and last ditch effort even after google:) It also never helped with this string but its useful to know.
And don't forget to run "makewhatis" occasionally (if not automatically done) so that the "man -k" and apropos have a current database to search.
<snip sig stuff>
On Thu, Oct 8, 2009 at 2:54 PM, Joseph L. Casale JCasale@activenetwerx.com wrote:
Just one of those things you kind of pick up as you go along and remember. Tribal knowledge if you will.
There's two pdf's and one command I use "often" :)
The redhat 5.3 deployment and installation pdf's (or the online versions)
That looks useful to know.
and:
# find /usr/share/doc/ -exec grep "PEERDNS" '{}' ; -print PEERDNS=yes|no file if PEERDNS is not set to "no". /usr/share/doc/initscripts-8.45.25/sysconfig.txt honor PEERDNS=no for pump and dhcpcd too (#18619) DEFROUTE defaults on; PEERDNS documented and defaults on /usr/share/doc/initscripts-8.45.25/ChangeLog
Now you know what doc to read...
Yeah, but by the time I knew PEERDNS was involved, all the hard work was done. Try that find command with 'resolv.conf' instead of PEERDNS and you get way too many hits.
mahalo, Dave
On Thu, Oct 8, 2009 at 2:20 PM, Ray Van Dolson rayvd@bludgeon.org wrote:
On Thu, Oct 08, 2009 at 01:32:39PM -1000, Dave wrote:
Wow, there it is. I guess I could've found it by doing a careful search of the initscripts package, which contains/owns /etc/sysconfig/network-scripts/ifcfg-eth0, which was the only script in /etc/ that invokes /sbin/dhclient, which a comment in /etc/resolv.conf revealed to be the program that wrote it.
Just one of those things you kind of pick up as you go along and remember. Tribal knowledge if you will.
Where exactly did you attempt to look first?
man 5 resolv.conf Not saying it was smart. second try was rpm -qf /etc/resolv.conf on the theory that some package ought to own every config file and have some sort of documentation about the files it owns. Not much of a theory.
I'm just trying to think of where a more obvious place to look would be first. Perhaps a man page documenting all the ifcfg type settings? man ifcfg?
That would have taken me just as long as this process did, since I had no connection in my brain initially between resolv.conf and ifcfg. I think if there was an obvious good candidate, we would not be talking about this, I'd have found my answer right away on my own.
I think Meenoo Shivdasani probably had the best idea, to google the message I found in my modified /etc/resolv.conf.
best, Dave
Dave wrote:
On Thu, Oct 8, 2009 at 11:44 AM, Craig White craigwhite@azapple.com wrote:
On Thu, 2009-10-08 at 11:19 -1000, Dave wrote:
[root@lee1 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
[snip]
PEERDNS=yes
- ^^^^^^^^^^^
change to PEERDNS=no
What man page would tell me what this means? How should I have known that's what I should do, if I were lacking the luxury of being told by one wiser than myself?
It's in /usr/share/doc/initscripts-<version>/sysconfig.txt
Cheers
frank
I haven't been following this thread very closely since my last post, but if you want to know who is doing what ... use auditctl. http://kbase.redhat.com/faq/docs/DOC-10108
Barry
Dave wrote:
[root@lee1 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 # Broadcom Corporation NetXtreme BCM5751 Gigabit Ethernet PCI Express DEVICE=eth0 BOOTPROTO=none HWADDR=00:18:8b:0f:ad:c2 IPADDR=1[snip]0 ONBOOT=yes DHCP_HOSTNAME=[snip] DNS1=1[snip]0 DNS2=1[snip].2 NM_CONTROLLED=no SEARCH=[snip] NETMASK=255.255.255.0 DNS3=1[snip]0 GATEWAY=1[snip]0.1 TYPE=Ethernet USERCTL=no PEERDNS=yes IPV6INIT=no
Holy cow, something put every single option in that file. For static address, the minimum you need is this:
DEVICE=eth0 BOOTPROTO=none HWADDR=00:18:8b:0f:ad:c2 IPADDR=1[snip]0 ONBOOT=yes NETMASK=255.255.255.0 TYPE=Ethernet
And you can either leave GATEWAY there or put it in /etc/sysconfig/network
I assume it's because of PEERDNS=yes, and you'll have to try to be sure, but anyway all that junk serves no purpose there (well, arguably you could put back USERCTL and stuff like that, if you really need it).
At Thu, 08 Oct 2009 14:54:36 -0700 CentOS mailing list centos@centos.org wrote:
Dave wrote:
[root@lee1 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 # Broadcom Corporation NetXtreme BCM5751 Gigabit Ethernet PCI Express DEVICE=eth0 BOOTPROTO=none HWADDR=00:18:8b:0f:ad:c2 IPADDR=1[snip]0 ONBOOT=yes DHCP_HOSTNAME=[snip] DNS1=1[snip]0 DNS2=1[snip].2 NM_CONTROLLED=no SEARCH=[snip] NETMASK=255.255.255.0 DNS3=1[snip]0 GATEWAY=1[snip]0.1 TYPE=Ethernet USERCTL=no PEERDNS=yes IPV6INIT=no
Holy cow, something put every single option in that file. For static address, the minimum you need is this:
DEVICE=eth0 BOOTPROTO=none
Shouldn't that be:
BOOTPROTO=static
HWADDR=00:18:8b:0f:ad:c2 IPADDR=1[snip]0 ONBOOT=yes NETMASK=255.255.255.0 TYPE=Ethernet
And you can either leave GATEWAY there or put it in /etc/sysconfig/network
I assume it's because of PEERDNS=yes, and you'll have to try to be sure, but anyway all that junk serves no purpose there (well, arguably you could put back USERCTL and stuff like that, if you really need it).
On Thu, Oct 8, 2009 at 1:04 PM, Robert Heller heller@deepsoft.com wrote:
At Thu, 08 Oct 2009 14:54:36 -0700 CentOS mailing list centos@centos.org wrote:
Dave wrote: BOOTPROTO=none
Shouldn't that be:
BOOTPROTO=static
My options (according to /usr/share/doc/initscripts-8.76.4/sysconfig.txt) are: BOOTPROTO=none|bootp|dhcp
This was all set by the network panel (/usr/bin/system-config-network).
I have an embarrassing admission to make - I just realized the system I was looking at is running fedora 9. I've noticed the same behavior on my centos systems, though.
Dave
At Thu, 8 Oct 2009 11:19:18 -1000 CentOS mailing list centos@centos.org wrote:
On Thu, Oct 8, 2009 at 9:49 AM, Spiro Harvey spiro@knossos.net.nz wrote:
chkconfig for dhclient too, and see what that results.
[root@ ~]# chkconfig --list|grep -e dh -e clie [root@ ~]#
Also, look at /etc/sysconfig/network-scripts/ifcfg-eth0.
[root@lee1 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 # Broadcom Corporation NetXtreme BCM5751 Gigabit Ethernet PCI Express DEVICE=eth0 BOOTPROTO=none
BOOTPROTO=static
HWADDR=00:18:8b:0f:ad:c2 IPADDR=1[snip]0 ONBOOT=yes DHCP_HOSTNAME=[snip]
???
DNS1=1[snip]0 DNS2=1[snip].2
???
NM_CONTROLLED=no SEARCH=[snip] NETMASK=255.255.255.0 DNS3=1[snip]0
???
GATEWAY=1[snip]0.1 TYPE=Ethernet USERCTL=no PEERDNS=yes
???
IPV6INIT=no
It's possible to have addresses "statically" assigned via DHCP based on MAC addresses. If resolv.conf is getting populated by dhclient, then I'm guessing the odds of you having a dhcp server on your network is good. :)
You guessed right. But the question remains, what software is writing the file?
In all likelihood, you have a static IP assigned in your ifcfg-eth0, and the resolv.conf is being over-written by dhclient.
What is invoking dhclient, how do I find it? rpm -qR dhclient /bin/bash initscripts >= 6.75 libc.so.6()(64bit) libc.so.6(GLIBC_2.2.5)(64bit) libc.so.6(GLIBC_2.3)(64bit) libc.so.6(GLIBC_2.3.4)(64bit) libc.so.6(GLIBC_2.4)(64bit) libc.so.6(GLIBC_2.8)(64bit) rpmlib(CompressedFileNames) <= 3.0.4-1 rpmlib(PayloadFilesHavePrefix) <= 4.0-1 rpmlib(VersionedDependencies) <= 3.0.3-1 rtld(GNU_HASH)
Dave _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Dave wrote:
My machine has a static IP, with dhcp and IPv6 disabled. Every time I reboot, some process rewrites /etc/resolv.conf, including a comment about dhcpclient. The only package I have installed that shows up in
What happens when you do this:
grep BOOTPROTO /etc/sysconfig/network-scripts/ifcfg-*
On Thu, Oct 8, 2009 at 10:10 AM, Florin Andrei florin@andrei.myip.org wrote:
What happens when you do this:
grep BOOTPROTO /etc/sysconfig/network-scripts/ifcfg-*
grep BOOTPROTO /etc/sysconfig/network-scripts/ifcfg-* /etc/sysconfig/network-scripts/ifcfg-eth0:BOOTPROTO=none
Dave
Dave wrote:
My machine has a static IP, with dhcp and IPv6 disabled. Every time I reboot, some process rewrites /etc/resolv.conf, including a comment about dhcpclient.
Is that dhcpclient, or dhclient?
The only package I have installed that shows up in "rpm -qa|grep -i dhcp" is dhcpv6-client-1.0.10-16.el5, and nothing in there is named dhcpclient.
What is the output of these commands?
rpm -qa | grep dhc # to see what's actually installed as a package
find / -name dhclient # to see if and where is the executable installed
grep -rI dhclient /etc | grep -v selinux | grep -v /ifup-eth: \ | grep -v /ifdown-eth: # to see if it's called from somewhere else than the regular places
On Thu, Oct 8, 2009 at 10:29 AM, Florin Andrei florin@andrei.myip.org wrote:
What is the output of these commands?
rpm -qa | grep dhc # to see what's actually installed as a package
rpm -qa | grep dhc dhcpv6-client-1.0.14-1.fc9.x86_64 libdhcp4client-4.0.0-22.fc9.x86_64 libdhcp6client-1.0.14-1.fc9.x86_64 libdhcp-1.99.8-1.fc9.x86_64 dhclient-4.0.0-22.fc9.x86_64
find / -name dhclient # to see if and where is the executable installed
I hope this is an acceptable substitute: rpm -qfs /sbin/dhclient normal /sbin/dhclient normal /sbin/dhclient-script normal /usr/share/doc/dhclient-4.0.0 normal /usr/share/doc/dhclient-4.0.0/dhclient.conf.sample normal /usr/share/man/man5/dhclient.conf.5.gz normal /usr/share/man/man5/dhclient.leases.5.gz normal /usr/share/man/man5/dhcp-eval.5.gz normal /usr/share/man/man5/dhcp-options.5.gz normal /usr/share/man/man8/dhclient-script.8.gz normal /usr/share/man/man8/dhclient.8.gz normal /var/lib/dhclient
grep -rI dhclient /etc | grep -v selinux | grep -v /ifup-eth: \ | grep -v /ifdown-eth: # to see if it's called from somewhere else than the regular places
Substituting: find /etc -type f -exec grep -iH dhclient {} ; | grep -v selinux /etc/bluetooth/network.conf:Script=dhclient /etc/rwtab:empty /var/lib/dhclient /etc/resolv.conf.save:; generated by /sbin/dhclient-script /etc/sysconfig/network-scripts/ifdown-eth:[ -n "`pidof -x dhclient`" ] && { /etc/sysconfig/network-scripts/ifdown-eth: if [ -f "/var/run/dhclient-${DEVICE}.pid" ]; then /etc/sysconfig/network-scripts/ifdown-eth: dhcpid=`cat /var/run/dhclient-${DEVICE}.pid` /etc/sysconfig/network-scripts/ifdown-eth: /sbin/dhclient -r -lf /var/lib/dhclient/dhclient-${DEVICE}.leases -pf /var/run/dhclient-${DEVICE}.pid ${DEVICE} >/dev/null 2>&1 /etc/sysconfig/network-scripts/ifdown-eth: reason=STOP interface=${DEVICE} /sbin/dhclient-script /etc/sysconfig/network-scripts/ifdown-eth: if [ -f "/var/run/dhclient-${DEVICE}.pid" ]; then /etc/sysconfig/network-scripts/ifdown-eth: rm -f /var/run/dhclient-${DEVICE}.pid /etc/sysconfig/network-scripts/ifup-eth:if [ -n "${DYNCONFIG}" -a -x /sbin/dhclient ]; then /etc/sysconfig/network-scripts/ifup-eth: # Remove any temporary references which were previously added to dhclient config /etc/sysconfig/network-scripts/ifup-eth: if [ -w /etc/dhclient-${DEVICE}.conf ] ; then /etc/sysconfig/network-scripts/ifup-eth: LC_ALL=C grep -v "# temporary RHL ifup addition" /etc/dhclient-${DEVICE}.conf > /etc/dhclient-${DEVICE}.conf.ifupnew 2> /dev/null /etc/sysconfig/network-scripts/ifup-eth: cat /etc/dhclient-${DEVICE}.conf.ifupnew > /etc/dhclient-${DEVICE}.conf /etc/sysconfig/network-scripts/ifup-eth: rm -f /etc/dhclient-${DEVICE}.conf.ifupnew /etc/sysconfig/network-scripts/ifup-eth: if [[ "${PERSISTENT_DHCLIENT}" = [yY1]* ]]; then /etc/sysconfig/network-scripts/ifup-eth: if [ -w /etc/dhclient-${DEVICE}.conf ] ; then /etc/sysconfig/network-scripts/ifup-eth: if ! LC_ALL=C grep "send *host-name *"${DHCP_HOSTNAME}"" /etc/dhclient-${DEVICE}.conf > /dev/null 2>&1 ; then /etc/sysconfig/network-scripts/ifup-eth: echo "send host-name "${DHCP_HOSTNAME}"; # temporary RHL ifup addition" >> /etc/dhclient-${DEVICE}.conf /etc/sysconfig/network-scripts/ifup-eth: elif ! [ -e /etc/dhclient-${DEVICE}.conf ] ; then /etc/sysconfig/network-scripts/ifup-eth: echo "send host-name "${DHCP_HOSTNAME}"; # temporary RHL ifup addition" >> /etc/dhclient-${DEVICE}.conf /etc/sysconfig/network-scripts/ifup-eth: # allow users to use generic '/etc/dhclient.conf' (as documented in manpage!) /etc/sysconfig/network-scripts/ifup-eth: if [ -s /etc/dhclient-${DEVICE}.conf ]; then /etc/sysconfig/network-scripts/ifup-eth: DHCLIENTCONF="-cf /etc/dhclient-${DEVICE}.conf"; /etc/sysconfig/network-scripts/ifup-eth: DHCLIENTCONF=''; /etc/sysconfig/network-scripts/ifup-eth: if [ -f /dev/.dhclient-${DEVICE}.leases ] ; then /etc/sysconfig/network-scripts/ifup-eth: mv -f /dev/.dhclient-${DEVICE}.leases /var/lib/dhclient/dhclient-${DEVICE}.leases /etc/sysconfig/network-scripts/ifup-eth: [ -x /sbin/restorecon ] && restorecon /var/lib/dhclient/dhclient-${DEVICE}.leases > /dev/null 2>&1 /etc/sysconfig/network-scripts/ifup-eth: DHCLIENTARGS="${DHCLIENTARGS} ${ONESHOT} -q ${DHCLIENTCONF} -lf /var/lib/dhclient/dhclient-${DEVICE}.leases -pf /var/run/dhclient-${DEVICE}.pid" /etc/sysconfig/network-scripts/ifup-eth: if [[ "${PERSISTENT_DHCLIENT}" != [yY1]* ]] && check_link_down ${DEVICE}; then /etc/sysconfig/network-scripts/ifup-eth: if /sbin/dhclient ${DHCLIENTARGS} ${DEVICE} ; then /etc/sudoers:Cmnd_Alias NETWORKING = /sbin/route, /sbin/ifconfig, /bin/ping, /sbin/dhclient, /usr/bin/net, /sbin/iptables, /usr/bin/rfcomm, /usr/bin/wvdial, /sbin/iwconfig, /sbin/mii-tool
Script=dhclient looks interesting, but that's for bluetooth?
On Thu, Oct 8, 2009 at 11:50 AM, Dave tdbtdb+centos@gmail.com wrote:
On Thu, Oct 8, 2009 at 10:29 AM, Florin Andrei florin@andrei.myip.org wrote:
What is the output of these commands?
rpm -qa | grep dhc # to see what's actually installed as a package
rpm -qa | grep dhc dhcpv6-client-1.0.14-1.fc9.x86_64 libdhcp4client-4.0.0-22.fc9.x86_64 libdhcp6client-1.0.14-1.fc9.x86_64 libdhcp-1.99.8-1.fc9.x86_64 dhclient-4.0.0-22.fc9.x86_64
find / -name dhclient # to see if and where is the executable installed
I hope this is an acceptable substitute: rpm -qfs /sbin/dhclient normal /sbin/dhclient normal /sbin/dhclient-script normal /usr/share/doc/dhclient-4.0.0 normal /usr/share/doc/dhclient-4.0.0/dhclient.conf.sample normal /usr/share/man/man5/dhclient.conf.5.gz normal /usr/share/man/man5/dhclient.leases.5.gz normal /usr/share/man/man5/dhcp-eval.5.gz normal /usr/share/man/man5/dhcp-options.5.gz normal /usr/share/man/man8/dhclient-script.8.gz normal /usr/share/man/man8/dhclient.8.gz normal /var/lib/dhclient
grep -rI dhclient /etc | grep -v selinux | grep -v /ifup-eth: \ | grep -v /ifdown-eth: # to see if it's called from somewhere else than the regular places
Substituting: find /etc -type f -exec grep -iH dhclient {} ; | grep -v selinux
[snip]
/etc/sysconfig/network-scripts/ifup-eth:if [ -n "${DYNCONFIG}" -a -x /sbin/dhclient ]; then /etc/sysconfig/network-scripts/ifup-eth: # Remove any temporary references which were previously added to dhclient config
[snip]
Previous poster Meenoo Shivdasani was close, looks like it is /etc/sysconfig/network-scripts/ifup-eth (not /etc/sysconfig/network-scripts/ifup) that invokes dhclient. Dave
At Thu, 8 Oct 2009 07:41:33 -1000 CentOS mailing list centos@centos.org wrote:
My machine has a static IP, with dhcp and IPv6 disabled. Every time I reboot, some process rewrites /etc/resolv.conf, including a comment about dhcpclient. The only package I have installed that shows up in "rpm -qa|grep -i dhcp" is dhcpv6-client-1.0.10-16.el5, and nothing in there is named dhcpclient.
I'd like to figure out what software is rewriting this file and why. man 5 resolv.conf and man resolver are unhelpful in this case. rpm reports /etc/resolv.conf is not owned by any package.
At this point, I am as (or more) interested in pointers regarding how to find the answer as I am in the actual answer. Please teach me to fish.
Is NetworkManager running? If so, stop it:
sudo /sbin/service NetworkManager stop
and disable it:
sudo /sbin/chkconfig NetworkManager off
mahalo, Dave _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
On Thu, Oct 8, 2009 at 1:04 PM, Robert Heller heller@deepsoft.com wrote:
Is NetworkManager running? If so, stop it:
/etc/init.d/NetworkManager status NetworkManager is stopped
mahalo, Dave
Dave wrote:
My machine has a static IP, with dhcp and IPv6 disabled. Every time I reboot, some process rewrites /etc/resolv.conf, including a comment about dhcpclient. The only package I have installed that shows up in "rpm -qa|grep -i dhcp" is dhcpv6-client-1.0.10-16.el5, and nothing in there is named dhcpclient.
I'd like to figure out what software is rewriting this file and why. man 5 resolv.conf and man resolver are unhelpful in this case. rpm reports /etc/resolv.conf is not owned by any package.
At this point, I am as (or more) interested in pointers regarding how to find the answer as I am in the actual answer. Please teach me to fish.
mahalo, Dave
Hi
Is network-manager enabled?
Regards
mg.
On Thu, Oct 8, 2009 at 11:40 PM, Marcelo M. Garcia marcelo.maia.garcia@googlemail.com wrote:
Is network-manager enabled?
No. Dave
The consensus of the list seemed to be that I should change the PEERDNS variable. It seems not to be working. The machine rebooted yesterday, /etc/resolv.conf got rewritten again. And yet:
find /etc/sysconfig/ -type f -exec grep -iH 'peerdns=' {} ; /etc/sysconfig/network-scripts/ifcfg-eth0:PEERDNS=no /etc/sysconfig/network-scripts/ifcfg-eth0.old:PEERDNS=yes /etc/sysconfig/networking/profiles/default/ifcfg-eth0:PEERDNS=no /etc/sysconfig/networking/devices/ifcfg-eth0:PEERDNS=no # chkconfig --list|grep Net NetworkManager 0:off 1:off 2:off 3:off 4:off 5:off 6:off # /etc/init.d/NetworkManager status NetworkManager is stopped # find /etc/sysconfig/ -type f -exec grep -iH 'bootproto=' {} ; /etc/sysconfig/network-scripts/ifcfg-eth0:BOOTPROTO=none /etc/sysconfig/network-scripts/ifcfg-eth0.old:BOOTPROTO=none /etc/sysconfig/network-scripts/ifup-eth: BOOTPROTO=bootp /etc/sysconfig/networking/profiles/default/ifcfg-eth0:BOOTPROTO=none /etc/sysconfig/networking/devices/ifcfg-eth0:BOOTPROTO=none # cat /etc/resolv.conf ; generated by /sbin/dhclient-script search soest.hawaii.edu nameserver 1... nameserver 1...
So, it's not PEERDNS, not DHCP, not NetworkManager. Why is dhclient-script even being run?
Maybe I should disable selinux altogether, instead of just making it permissive? I think I'll try that.
# grep resol /sbin/dhclient-script make_resolv_conf() { save_previous /etc/resolv.conf change_resolv_conf $rscf for resolvfile in /etc/resolv.conf* ; do /sbin/restorecon $resolvfile >/dev/null 2>&1 make_resolv_conf if [ -f /etc/resolv.conf.predhclient.$interface ]; then change_resolv_conf /etc/resolv.conf.predhclient.$interface rm -f /etc/resolv.conf.predhclient.$interface [root@lee1 ~]# getenforce Permissive
How badly would things blow up if I did this?
chmod a-w /etc/resolv.conf
mahalo, Dave
On Thu, Oct 8, 2009 at 7:41 AM, Dave <tdbtdb+centos@gmail.comtdbtdb%2Bcentos@gmail.com
wrote:
My machine has a static IP, with dhcp and IPv6 disabled. Every time I reboot, some process rewrites /etc/resolv.conf, including a comment about dhcpclient. The only package I have installed that shows up in "rpm -qa|grep -i dhcp" is dhcpv6-client-1.0.10-16.el5, and nothing in there is named dhcpclient.
I'd like to figure out what software is rewriting this file and why. man 5 resolv.conf and man resolver are unhelpful in this case. rpm reports /etc/resolv.conf is not owned by any package.
At this point, I am as (or more) interested in pointers regarding how to find the answer as I am in the actual answer. Please teach me to fish.
mahalo, Dave
/etc/sysconfig/network-scripts/ifup-eth: BOOTPROTO=bootp
So, it's not PEERDNS, not DHCP, not NetworkManager. Why is dhclient-script even being run?
BOOTPROTO=bootp is triggering it.
In /etc/sysconfig/network-scripts/ifup-eth:
if [ "${BOOTPROTO}" = "bootp" -o "${BOOTPROTO}" = "dhcp" ]; then DYNCONFIG=true fi
Then, later on in that script:
if [ -n "${DYNCONFIG}" -a -x /sbin/dhclient ]; then
do a bunch of stuff related to dynamically assigned addresses and names.
And finally:
if /sbin/dhclient ${DHCLIENTARGS} ${DEVICE} ; then echo $" done." else
Maybe I should disable selinux altogether, instead of just making it permissive? I think I'll try that.
selinux shouldn't have anything to do with the resolv.conf file being rewritten -- unless it's set to enforcing and something that isn't allowed to do so is trying to rewrite the file.
HTH,
M
On Thu, Oct 29, 2009 at 9:00 AM, Meenoo Shivdasani meenoo@gmail.com wrote:
BOOTPROTO=bootp is triggering it.
I'm confused. I just rebooted another machine with 'BOOTPROTO=bootp' in /etc/sysconfig/network-scripts/ifup-eth, it did not rewrite /etc/resolv.conf.
Okay, my goof, the one with the problem is actually running fc9. Sorry.
I will try
sed -i "s/BOOTPROTO=bootp/BOOTPROTO=none/" /etc/sysconfig/network-scripts/ifup-eth
mahalo, Dave
On 10/29/2009 04:03 PM Dave wrote:
On Thu, Oct 29, 2009 at 9:00 AM, Meenoo Shivdasani <meenoo@gmail.com mailto:meenoo@gmail.com> wrote:
BOOTPROTO=bootp is triggering it.I'm confused. I just rebooted another machine with 'BOOTPROTO=bootp' in /etc/sysconfig/network-scripts/ifup-eth, it did not rewrite /etc/resolv.conf.
....
I haven't followed the entire discussion, but do you have correct settings in /etc/sysconfig/networking/devices/ifcfg-eth0 (or whatever the NIC is) and the two relevant files in /etc/sysconfig/networking/profiles/default/ ??
hth, ken
ken wrote:
On 10/29/2009 04:03 PM Dave wrote:
On Thu, Oct 29, 2009 at 9:00 AM, Meenoo Shivdasani <meenoo@gmail.com mailto:meenoo@gmail.com> wrote:
BOOTPROTO=bootp is triggering it.I'm confused. I just rebooted another machine with 'BOOTPROTO=bootp' in /etc/sysconfig/network-scripts/ifup-eth, it did not rewrite /etc/resolv.conf.
....
I haven't followed the entire discussion, but do you have correct settings in /etc/sysconfig/networking/devices/ifcfg-eth0 (or whatever the NIC is) and the two relevant files in /etc/sysconfig/networking/profiles/default/ ??
hth, ken
To add to Ken's answer... The setting is PEERDNS in the /etc/sysconfig/network-scripts/ifcfg-eth? file. If PEERDNS is set to "yes" then the resolv.conf file will be rewritten on every reboot. If set to "no" then the resolv.conf should not change.
BTW, I have not read the OP's original post and basing my answer just on the subject line.
Phil
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