CentOS

Hello All,
I installed lately Elastix 2.5 which is working on centos 5.10 Final and I wanted to assign the IP Address + Gateway. I already did that but I can't ping the Gateway for some reason. This is my config, Am I missing something? I'm new on Linux and I saw a lot of discussions and forums and tried so many thing like routing etc.. but none worked with me so a hint would be great!
Configuration attached

You're missing, among many other things, going on for 4 years of security fixes on CentOS 5 which died a very long time ago and should no longer be used for anything. Do not use it. Most especially do not use it if you are exposing it to the internet in any way whatsoever. It is not safe. Find an alternative.

CentOS 6 follows CentOS 5 into the grave in about 6 months so it's not a good replacement either. Find something recent with a decent amount of support life left in it. At present you are running the equivalent of Windows XP with no maintenance.

@TrevorH Thanks for the reply, I know that centos 5 is very old and its not practical to use it. But I have packaged iso which is elastix 2.5 working on centos 5.10, and its not gonna be on internet only on lan so I guess its fine but I have to make it work. any tips about the gateway would be great

Thanks,
regards

Elastix is a PBX and if you aim to receive calls from other people outside your LAN then it will need to talk to the internet.

Really, find an alternative. It's a compromise just waiting to happen.

@TrevorH I know its a PBX and I installed the same version I'm talking about in more than 10 locations and its working fine with Voice routers provided by the country's ISP. But the network wasn't an issue for me before till now with new customer the network is complex and gateway must be set.
I really need this to work its urgent because of quarantine I have no time to figure everything out all over again with another PBX or Centos version.

Regards,
Nasser