Birmingham mumbai

Virtual IP
 or 
VIP
) for a pool of servers, with this special IP being applied to a 
single server at a time. Each installation of 
keepalived
 in the same group will be able 
to detect when another server isn't available, and claim ownership of the floating 
IP whenever the primary server isn't responding. This allows you to run a service 
on multiple servers, with a server taking over in the event that another becomes 
unavailable.

---

Chapter 14
[
 371 
]
Let's talk a little bit about how 
keepalived
 can work with Apache in theory. 
Once 
keepalived
 is installed on two or more servers, it can be configured such 
that a primary server will have ownership of the floating IP, and other servers 
will continually check the availability of the primary, claiming the floating IP for 
themselves whenever the current primary becomes unreachable. For this to work, 
each server would need to contain the same Apache configuration and site files. I'll 
leave it up to you to set up multiple Apache servers. If you've followed along so far, 
you should have at least one already. If it's a virtual machine, feel free to create a 
clone of it and use that for the secondary server. If not, all you should have to do is 
set up another server, following the instructions earlier in this chapter. If you're able 
to view a website on both servers, you're good to go.
To get started, we'll need to declare a floating IP. This can be any IP address that's 
not currently in use on your network. For this to work, you'll need to set aside an 
IP address for the purposes of 
keepalived
. If you don't already have one, pick an IP 
address that's not being used by any device on your network. If you're at all unsure, 
you can use an IP scanner on your network to find an available IP address. There 
are several scanners that can accomplish this, such as 
nmap
 on Linux or