Shell Programming and Scripting

Hello, Newbie question on scripting - I'm looking to create a simple script that will work on RHEL5 that will adjust the network settings: ip address, default gateway, and subnet mask. If anything else needs to be done (service network stop / start) or should be done to make settings active - I want to include that - then ping to a public IP and confirm a successful response.
Thanks for your input

looks like homework to me...?!

No sir, it is not. I am provisioning RHEL virtual machines and need to automate checking and updating the network configuration of them afterwards.

so show us what you have done so far... nobody is going to write scripts for you because this is your job. you have to start and if specific problems occur, you can always ask. for starters, you might want to take a look at commands like "ifconfig" (for checking your network) and "sed" or "ed" for editing files from a script.

The main issue I'm having is with the default gateway. After provisioning a virtual machine, the default gateway for some reason does not populate. So the main problem is to script the population of the default gateway

So in what I've tried so far,

This line is intended to populate the default gateway:

route add default gw 192.168.26.1

but results in the following message:

SIOCADDRT: File Exists


Some postings suggest steps such as this:

1. Open ifcfg file vi /etc/sysconfig/network-scripts/ifcfg-eth0:7
2. NETWORK=217.174.242.0 Make sure this address is unique to each ifcfg file; if you use the same address in another ifcfg file you will receive the aforementioned error.
3. Edit if required by pressing i to begin insert mode, make the changes, then pressing Esc to return to view mode.
3. Save the document by using a SHIFT ZZ combination.
4. Restart the network: service network restart


But having to that for every vm would defeat my object of saving time through scripting the process.

Thanks