Mass Change Of IP's

[n2972s]

We have to change all the IP's on our server.

I am wondering if anybody has any idea on how to mass change the IP's of all our sites on the server.

What we want to do is do a mass change from our old shared IP to the new shared IP.

Any info would be appreciated.

Thanks

 

[cyrus]

I know this post is way too old, but recently our datacenter changed their entire IP range and this is what we did.


Note: For this example, I assume that you are using a regular Linux Distro (RH/CentOS/FC) and have the /usr/bin/replace command which comes with MySQL-server.xx.rpm. I also assume that your datacenter has configured both old aswell as the new networks on their router.

OLD IP : 10.x.x.x with default route 10.x.x.1
NEW IP : 11.x.x.x with default route 11.x.x.1

Firstly add the new IP range using WHM->IP Functions (don't add the new base IP address).
Ping few of these newly added IPs just to make sure that everything is ok.

Reduce the TTL of all dns zones to something like 600 seconds.

cd /var/named
replace 14400 600 -- *.db
/usr/sbin/rndc reload

Take a backup of all the configuration files which will be modified by this script:

#!/bin/bash
# 10.x.x.x = OLD IP Range
# 11.x.x.x = NEW IP Range

cd /etc/httpd/conf
replace 10.x.x.x 11.x.x.x -- httpd.conf
service httpd restart

cd /var/named
replace 10.x.x.x 11.x.x.x -- *.db
rndc reload

cd /var/cpanel
replace 10.x.x.x 11.x.x.x -- *

cd /var/cpanel/dips
replace 10.x.x.x 11.x.x.x -- *

cd /var/cpanel/mainips
replace 10.x.x.x 11.x.x.x -- *

cd /var/cpanel/users
replace 10.x.x.x 11.x.x.x -- *

Once this script runs successfully, we will change the base IP address of the system. Assuming that your main interface is eth0, edit the file /etc/sysconfig/network-scripts/ifcfg-eth0 and carefully change the IP, Broadcast, Netmask, etc. to that of the new IP range.

From:

DEVICE=eth0
BOOTPROTO=static
BROADCAST=10.x.x..255
IPADDR=10.x.x.x
NETMASK=255.255.255.0
NETWORK=10.x.x.0
ONBOOT=yes

To:

DEVICE=eth0
BOOTPROTO=static
BROADCAST=11.x.x..255
IPADDR=11.x.x.x
NETMASK=255.255.255.0
NETWORK=11.x.x.0
ONBOOT=yes

Now we change the default route by editing /etc/sysconfig/network :

From:

NETWORKING=yes
HOSTNAME=your.hostname
GATEWAY=10.x.x.1

To:

NETWORKING=yes
HOSTNAME=your.hostname
GATEWAY=11.x.x.1

Also, if you are using your datacenter's DNS don't forget to change your DNS servers in /etc/resolv.conf

Thats about it, its better you check the configs once again and reboot the machine (alternately you can also restart each service )

All the best :D




P.S: I forgot to add one more thing, after a day or so, change the TTL of all your zone files back to original

cd /var/named
replace 600 14400  -- *.db
/usr/sbin/rndc reload

 

[gorilla]

or just simply log into WHM > Multi-Account Functions >Change Multiple Sites' IP
which might be easier

 

[cyrus]

Oh sorry I forgot to mention, that function is utterly useless when it comes to changing 100+ IPs on a system with more than 400 accounts. Try it and you'll see

 

[dave9000]

Everytime I have used the change mutli account ips script I have to limit it to no more than 4 sites at a time and if a large site do only 1 at a time or the script will hang and then have to do the kill -9 pid on all hung processes and start over

 

[gorilla]

Have changed up to 20 sites IP at one time with the WHM feature
Havent had to do more so I wouldnt really know how it would do , but just a week ago the change of the 20 sites IP was fine

 

[chirpy]

And once again, when you change a zone file contents you should increase each SERIAL number otherwise you are asking for propagation problems.

 

[ntwaddel]

so does the whm multiple update program increment the serial #?

 

[chirpy]

I would hope so, I've not had any issues with it of late.

 

[ntwaddel]

so how does that work exactly, do i need to setup all the new ips, then use that tool and remove the old ips?

 

[chirpy]

Yes, that's it

 

[ntwaddel]

what about the primary ip

can i change it in
/etc/sysconfig/network-scripts/ifcfg-eth0

then will it be listed as an option to switch the ips to in the whm feature

 

[ntwaddel]

what about the IP Migration tool, how does that work exactly?

I have 12 ip's on this server, the main shared ip is the primary ip address on the box, then 11 other sites with a dedicated ip.

 

[ntwaddel]

the wizard actually worked pretty good, a couple snags, but no show stoppers