When moving a radius service from one machine to another I had to do the following:
On the first machine bring down the IP address:
ifconfig eth0 down
On the new machine, create a file for the new IP address:
vi /etc/sysconfig/network-scripts/ifcfg-eth0:1
DEVICE=eth0:1
BOOTPROTO=static
HWADDR=00:16:3E:6D:BD:63
IPADDR=123.111.1.2
NETMASK=255.255.255.0
NETWORK=123.111.1.0
ONBOOT=yes
And bring up the interface with:
/etc/init.d/network restart
or
ifconfig eth0:1 up
It may take a few minutes for the Arp-Ip tables on the switches to update but issuing the following may help (where 123.117.1.2 is the new IP address the Arp of which you want to advertise to the switches):
arping -U -I eth0 123.117.1.2
Then test the radius response using NTRadPing or the following:
echo "User-Name=33-22-BA-14-A2-F8,Password=testing123" | radclient -t 2 123.111.1.2:1812 auth testing123
radclient: received response to request we did not send. (id=241 socket 3)
radclient: received response to request we did not send. (id=241 socket 3)
radclient: received response to request we did not send. (id=241 socket 3)
radclient: no response from server for ID 241 socket 3
Oops I forgot to configure Radius to listen on the new IP address so edit /etc/raddb/radius.conf and set the bind_address value:
bind_address = 123.111.1.2
On Freeradius version 2 the line is:
ipaddr = 123.111.1.2
Test it again:
echo "User-Name=33-22-BA-14-A2-F8,Password=testing123" | radclient -t 2 123.111.1.2:1812 auth testing123
Hopefully a succesful response like this:
Received response ID 164, code 2, length = 20