Changing server IP address from DHCP not working

khooke · 09-25-2005, 12:35 AM

When my Fedora Core 4 server is configured to use DHCP the internet connection via my hub (on 192.168.0.1) works as expected.

I'd like to change the IP to be a fixed address, say 192.168.0.4. If I change it using

Code:

ifconfig eth0 192.168.0.4

I lose internet connectivity - it seems that I can no longer resolve domain names, and I can not ping the nameservers either.

My resolve.conf:

Code:

nameserver 206.13.31.12
nameserver 206.13.28.12
search localdomain

Output from route -e:

Code:

Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
192.168.0.0     *               255.255.255.0   U         0 0          0 eth0
169.254.0.0     *               255.255.0.0     U         0 0          0 eth0
default         192.168.0.1     0.0.0.0         UG        0 0          0 eth0

As soon as I change it using the ifconfig command, I can no longer access the internet. I'm assuming that this is the corect way to do this, but its obviously not working. What do I need to do to correctly change the IP address?

Thanks!

debianmike · 09-25-2005, 12:57 AM

i'd add netmask 255.255.255.0 and maybe even gw 192.168.0.? to your ifconfig command.

If you want to make it perminant, look at the /etc/sysconfig/network-scripts/ifcfg-eth0 file.

RH networking kind-of sucks. If you use their GUI tool, it creates a different config file somewhere else, so do a search for ifcfg-eth0 and see if you have multiple ones.

khooke · 09-25-2005, 01:19 AM

That works great, thanks. If I add that to the command then the IP changes and I still have connectivity. I'm unsure how to make this a permanent change though, as the content in the ifcfg-eth0 file does not seem to match up with what I have in the command. Anyone else know how to do this?

Thanks!

debianmike · 09-25-2005, 09:00 AM

what is in ifcfg-eth0?

Should be things like:

ONBOOT=yes
USERCTL=no (or yes)
IPADDR=1.1.1.1
NETMASK=
GATEWAY= (See note below)
MACADDR=(See note below)
NETWORK=1.1.1.0
BROADCAST=1.1.1.255

Redhat monkies with the gateway...it may be in /etc/sysconfig/network instead.

MACADDR is not needed to much, but make sure it is unique on your network.

Userctl is if you want users to be able to start/stop this nic.