[SOLVED] New install - error host already uses address

kongfranon · Post by **kongfranon** » 2011/12/06 17:17:26

Hi,

I just intalled CentOS 6 for the first time, I have used 5.5/5.6 before. After I configured networking through the install, and restarted the box I noticed no connectivity.

If I do a

ifup eth0

Error, some other host already uses adress 192.168.100.30

I know no other machine is using it, and I did disabled SeLinux and restarted the box again.

I am not sure what I am missing?

Thanks

pschaff · Post by **pschaff** » 2011/12/06 18:36:00

Welcome to the CentOS fora. Please see the recommended reading for new users linked in my signature.

SELinux should have nothing to do with the network starting, and disabling it is not recommended, rather "setenforce 0" to temporarily go to Permissive mode if required for testing/debugging.

Perhaps you are not aware of the upstream changes to the defaults for networking, including use of NetworkManager in place of the "network" service. See [url=http://wiki.centos.org/FAQ/CentOS6#head-b67e85d98f0e9f1b599358105c551632c6ff7c90]FAQ #2. Why does my Ethernet not work unless I log in and explicitly enable it?[/url]

If more help is needed then please [url=http://www.centos.org/modules/newbb/viewtopic.php?topic_id=28723&forum=54]provide more information about your system[/url] by running "./getinfo.sh [b]network[/b]" and showing us the output file.

Post by **TrevorH** » 2011/12/06 20:49:56

[quote]
Error, some other host already uses adress 192.168.100.30
[/quote]

If it says that then I would believe it and investigate your network to find out where it is. Install using a different IP address then ping the address you wanted to use and run arp afterwards to see if it lists a MAC address for that IP.

kongfranon · Post by **kongfranon** » 2011/12/06 21:48:15

Thanks I got it to work, I think it had to do with the NIC was on the wrong VLAN, but I thought it was odd, since usually it would start up but just could not route anywhere or so I thought.

out of curiosity how do you start up network manager on the command line? this is for a server and don't have the gui installed, I usually just vi /etc/sysconfig/network-scripts/ifcfg-eth0

Thanks again

pschaff · Post by **pschaff** » 2011/12/06 22:02:26

The NetworkManager service should be started by default.[code]
# chkconfig --list | grep -i network
NetworkManager 0:off 1:off 2:on 3:on 4:on 5:on 6:off
network 0:off 1:off 2:on 3:on 4:on 5:on 6:off[/code]

For command line configuration see "man nmcli", "man nm-tool", "man nm-online" "man NetworkManager.conf", and "man nm-system-settings.conf"

kongfranon · Post by **kongfranon** » 2011/12/07 14:38:18

Thanks for the help!

I was trying to figure out where to hit the solved button, or how to mark this thread solved?

I cannot seem to edit my first post.

pschaff · Post by **pschaff** » 2011/12/07 15:44:51

Just reply with [SOLVED] (or [RESOLVED] if more appropriate) in the subject, as explained in [url=http://www.centos.org/modules/newbb/viewtopic.php?topic_id=28726&forum=54]Readme First[/url], and a moderator should come along and mark the head of the thread on your behalf. The current brain-damaged forum software does not allow a user to do so.

Thanks for reporting back. Marking this thread [SOLVED] for posterity.

CentOS