Change ip using sed command

glennbtn · 08-01-2016, 04:59 AM

Hi All

We have a backup server which sometimes needs to be the master machine which just involves changing the ip address.

What I would like to do is have a bash script that will change the ip restart the service etc so it's up and running quick.

Can anyone tell me how I would change the ip using say the sed command from say my 10.10.10.2 address to 10.10.10.3

I have tried different examples found on the net but nothing seems to work. I would be looking to change the /etc/network/interfaces file

Thanks

Glenn

syg00 · 08-01-2016, 05:05 AM

Safer to have another file correctly set up in advance and merely copy it over. Make sure you have a backup of the original.

As for the sed, looks trivial - show us what you did, and what happened.

glennbtn · 08-01-2016, 05:09 AM

I have tried various 1's but non seem to work. No errors but no changes either

sed 's/10.10.10.2/10.10.10.3/'
sed -i -e "s@\b$10.10.10.2\b@$10.10.10.3@g"
sed -i -e "s/$10.10.10.2\b/$10.10.10.3/g"

Thanks

Glenn

syg00 · 08-01-2016, 05:28 AM

First two look sane - would need to see the file content and permissions.

keefaz · 08-01-2016, 11:04 AM

You can change ip on the fly using ifconfig too...

24x7servermanagement · 08-01-2016, 07:45 PM

sed -i.bak 's/127.0.0.1/127.0.0.2/g' Path/of/filename

Should work fine. (-i.bak - create backup file of original file)

What is the error you are getting when you fire above command?

chrism01 · 08-02-2016, 02:49 AM

I'm with syg00, make 2 copies of the file and simply copy over whichever you need at any given time.
This way if something happens, you can easily recover & cp is simpler than sed

michaelk · 08-02-2016, 05:24 AM

I agree with keefaz you can change the IP on the fly by adding an alias or changing the interface by using the ip or the legacy ifconfig command which depends on your distribution. No need to restart anything.

I assume your services are configured to listen to all interfaces.

https://tty1.net/blog/2010/ifconfig-...arison_en.html