IP Address Changes

[Andrew Crowe_2]

Our company is demerging and in about six weeks time we are moving to a new network. I have to change the servers IP Address. I will do this via set_parms. Is this the best way to set new IP address's and are there any major implications?

[Leif Halvarsson_2]

Hi
Perhaps you will get problem using CDE (logging in). I have noticed such problems when changing IP-adress or domain. It is always possible to log in using "Failsafe session", telnet, rlogin or a terminal. I have no good solution for this, sometimes it helps with loggin in using Failsafe session and then logout again.

[Stefan Farrelly]

We had a similar exercise here. set_parms ip_address works fine. It asks for a reboot once its made its changes so ensure all your apps are down once you run it.

We also had to change subnetmask so used set_parms addl_netwrk and this caused problems. Because once you input new subnetmask and def gateway the set_parms script tries to reconfig the network straight away - and if youre new network is not available yet (def gateway not up) then set_parms hangs without having properly updated /etc/rc.config.d/netconf fully - so watch out for this if youre changing subnetmask/def gateway.

[Shahul]

Hi

I select set_parms for this. Halt the applications which are running. then

#set_parms ip_address
#cd /etc/rc.config.d
#more netconf This is to confirm the change.

Best of luck
Shahul

[Peter Kloetgen]

Hi Andrew,

set_parms seems to be the best choice, perhaps you should run it the following way:

set_parms initial

This command gives you the possibility to change other parameters like subnet mask, DNS, hostname and so on...

Allways stay on the bright side of life!

Peter

[Andrew Crowe_2]

Thanks for the advice. it is much appreciated.

Hopefully I won't be back here panicking in a few weeks time.

Thanks again

Andrew

[Sukant Naik]

Hi Andrew,

As all have said earlier, set_parms is the best option.

One word of caution.
I have done a similar execrise three times last year of changing the IP address of all the servers.

1. Always unexport all the filesystems which you had exported and most important unmount all nfs filesystems. I faced the problem because I had to few server names too.

2. Applications like Oracle have listeners file. Check for them if they contain IP address for any TNS and change them accordingly.

3. Change in IP address did not affect my ClearCase server at all.

-Sukant

[Chris Wilshaw]

It's also worth remembering that you'll need to update any name resolution on any DNS servers too (and in hosts files on other servers that are associated to this one if DNS is not being used). As a precaution, you may also want to check host equivalency if you need to keep the parts of the company totally separate.

Another problem that I've encountered in the past is that occasionally, people hard code IP addresses into scripts/programs (not generally a good idea), so if you think that this is likely, try

find / -exec grep -l {} \;

This will give you a list of all files containing the IP address.

Chris

[George Abraham_1]

hai

Do the set_parms Ip command and then make sure for netconf file wheather the change has been made properly

cheero
george

[Sebastian Galeski_1]

Hi
thats true that set_parms is the best way to change ip address, but check if there are right entry in /etc/rc.config.d/netconf and in /etc/hosts.
Before you decide to change ip address check if some application will work. Some application like all openView family based on license which base on ip address, so you will need to generate license keys again.

[PIYUSH D. PATEL]

Hi,

Whenever you change the ip address there are lot of consideration to be made :

What applications are running on your server which are IP based and what implications it will have on the users which are running the s/w. So keep into mind all the factors and then change the ip_address to set_parms ip_address

Piyush

[John Waller]

Using "set_parms initial" will work fine, but I personally manually change the /etc/rc.config.d/netconf file and /etc/hosts file. I manually change the files as I find it quicker, specially if you only are changing a couple of entries. (normally IP_ADDRESS[0] and ROUTE_GATEWAY[0]). Also beaware if you are using DNS that you will also need to change your DNS files or /etc/resolv.conf.

[Robert Sipe]

set_parms is the best way to reset your ip address as well as your hostname, & date-time. However, problems may appear on other systems if the developers did not use host name. I guess they would have problems anyway if the server is going to a new network.

[U.SivaKumar_2]

Hi,
While you are moving to new IP addressing scheme , you have to note down there are Applications which have IP address based licensing like HP omniback, SAP R3, HP NNM etc. So you will have to move the licenses to
new IP address for the applications to function
properly. Most of this license moving activities are fast.

regards,
U.SivaKumar