Centos server keeps jumping to address instead of static assigned address
Solution 1
plain and simple solution: deinstall what you dont need :)
yum remove dhclient
Solution 2
You don't need PEERDNS
since you're using a static IP. This is causing dhclient
to run and update your resolv.conf
file (as it's designed to do). In the process, it also requests an IP address when it requests the nameservers from DHCP.
Solution 3
To assign a fixed IP address, use none
as the value for BOOTPROTO
.
From the "RHEL5 Deployment Guide", section "Interface Configuration Files":
BOOTPROTO=protocol
where
protocol
is one of the following:
none
— No boot-time protocol should be used.bootp
— The BOOTP protocol should be used.dhcp
— The DHCP protocol should be used.
Solution 4
Maybe I'm a hack, but I like using the system-config-network-tui
utility on RHEL/CentOS/RPM-based system for this, as it helps clean up any funky or hand-(mis)configured interface scripts.
Related videos on Youtube
blarg
Updated on September 18, 2022Comments
-
blarg over 1 year
I have a headless Centos server that I've configured with a static IP address. I've disabled Network Manager, avahi-daemon etc. Whenever I restart the network it just jumps to 10.155.90.100 instead of the required 10.155.90.61 with no explanation:
Here is my ifcfg-eth0:
# Intel Corporation 82545EM Gigabit Ethernet Controller (Copper) DEVICE=eth0 BOOTPROTO=static ONBOOT=yes #HWADDR=00:50:56:b0:5a:57 IPADDR=10.155.90.61 NETMASK=255.255.255.0 GATEWAY=10.155.90.1 TYPE=Ethernet USERCTL=no IPV6INIT=no PEERDNS=yes NM_CONTROLLED=no
It seems to be running DHCP anyway. I cant seem to get a more detailed log than this in /var/log/messges:
Jul 11 12:50:33 NET[4767]: /sbin/dhclient-script : updated /etc/resolv.conf Jul 11 12:50:34 kernel: 8021q: adding VLAN 0 to HW filter on device eth0 Jul 11 12:50:34 kernel: ADDRCONF(NETDEV_UP): eth0: link is not ready Jul 11 12:50:34 kernel: e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: None Jul 11 12:50:34 kernel: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready Jul 11 12:50:36 dhclient: DHCPREQUEST on eth0 to 255.255.255.255 port 67 (xid=0x39edae98) Jul 11 12:50:36 dhclient: DHCPACK from 10.155.50.20 (xid=0x39edae98) Jul 11 12:50:36 NET[5157]: /sbin/dhclient-script : updated /etc/resolv.conf Jul 11 12:50:36 dhclient: bound to 10.155.90.100 -- renewal in 255205 seconds.
How can I turn off DHCP and stop the server jumping for the wrong IP?
-
Dennis Nolte almost 10 yearsdeinstall the service? dhclient
-
blarg almost 10 years@DennisNolte. That fixed it!
-
-
MadHatter almost 10 yearsI don't think that's right; I use
BOOTPROTO=static
very happily in all sorts of CentOS boxes, specifically both C5 and C6, with no problems. -
iSee almost 10 yearsMaybe he should have a look at the documentation i.e.
less /usr/share/doc/initscripts-*/sysconfig.txt
and search forBOOTPROTO
. It saysBOOTPROTO=none|bootp|dhcp
on Scientific Linux 6.5. -
Nathan C almost 10 yearsIt appears
none
orstatic
is dependent on the OS. RHEL5 changed it, but from the research I've done (like this wiki) CentOS still usesstatic
. -
ewwhite almost 10 yearsOr just stop the service.
-
Andrew almost 10 yearsIt will fix this problem but it's a bit "brute force". What if other interfaces need DHCP? I would investigate Nathan C's answer below about PEERDNS.